[GUIDE] In-depth Guide to CKII

[Meneth]

This guide was started on the Paradox plaza sub-reddit on Reddit as an in-depth guide to various concepts in CKII. After I had posted a few installments, I started a thread on this forum as well so as to reach a larger audience. The original post in that thread eventually went over the character limit, and I therefore made this thread based on the recommendations of a moderator, and have split the guide into several posts instead of one large post.
Any feedback can be posted over in this other thread.

Index:

Installment 1 - The Feudal System and Its Implications
Installment 2 - Construction; Where, When, and What
Installment 3 - Technology; Why and How
Installment 4 - Succession Laws; Pros and Cons
Installment 5 - Taxation; Inner Workings and Maximization
Installment 6 - Levies; Inner Workings and Maximization
Installment 7 - Marriage and Children; Ensuring Your Future
Installment 8 - Claims and Casus Belli; Expanding Your Realm
Installment 9 - Warfare; Diplomacy By Other Means
Installment 10 - Religion; Keeping the Church Strong
Installment 11 - Culture; Unity Through Homogeneity
Installment 12 - Holding Types
Installment 13 - Crown Law
Installment 14 - Distribution of Power; Keeping Your Vassals Weak
Installment 15 - Councilors; Rulers Need Advisers
Installment 16 - Breeding; Eugenics For A Better Future
Installment 17 - Education; Avoiding Idiocracy

 

[Meneth]

The Feudal System and Its Implications
First posted here.

Ten installments have so far been published, and at this point it has become obvious that my first installment, about The Feudal System, is not up to the same standard as the rest. Therefore I've rewritten it and expanded it further in an attempt to make it more exhaustive and to link to other relevant installments. In Feudal Europe, society had a highly hierarchical structure. Everyone had someone above them in the hierarchy whom they defer to. Crusader Kings II tries to replicate this structure, which has various gameplay implications.

The Basics
Everyone you can interact with in CKII has subjects below him/her, and almost everyone has a liege whom he has to defer to. In general anyone below you will pay you taxes and provide you troops, while you do the same for those above you. Power thus trickles upwards, and the highest ruler is generally the most powerful noble in a realm, but as his subjects only provide a fraction of their power to him it is still possible for him to be less powerful than some of his subjects. A good example of this would be the relationship between the king of France and the duke of Aquitaine in 1066, where the duke of Aquitaine has massive personal holdings and a larger power-base than his liege, the king of France.
While in Medieval society all titles are granted by the grace of God, in reality this power once attained relies merely on two things: power and opinion. All the God-granted rights in the world will not help you if you are opposed by every nobleman in your realm, and your rightful rule can easily be undone by mortal hands. Your subjects power and opinion of you will thus affect most aspects of your realm.

The Economical Aspect
More detail here.

First off there's the economic aspect of it. Every vassal has the potential to pay you tax, and if they'll pay you and how much they pay you is dependent on three factors:

1. Their income
2. Your tax laws
3. Their opinion of you

The first factor is simple. The more a vassal earn, the more (s)he can potentially pay you. The second factor is your laws which decide what percentage of their income they're supposed to pay you. However, they'll only pay you this much if they like you. The third factor is their opinion of you. As long as a vassal likes you he'll pay his due taxes to the best of his ability. If he dislikes you, he'll pay you less
Thus, if you're unable to keep your vassals happy you will have very little income beyond what you get from your own personal holdings. If you're catholic you'll also have to make sure your bishops prefer you over the pope for them to pay you any tax whatsoever.
Therefore, you have to strike the right balance between tax law and vassal opinion if you are to run a good economic surplus. High tax law helps nothing if all your vassals hate you.

The Military Aspect
More detail here.

The Feudal system also decides how much military power your vassals provide to you. How much they'll provide to you, like taxes, depends on three factors:

1. Their manpower
2. Your levy laws
3. Their opinion of you

These three factors work essentially the same way as it does for tax. The more powerful a vassal, the higher the levy laws, and the higher their opinion of you, the more military power you'll have.
If you're unable to keep your vassals happy you'll end up with no military power beyond what the crown laws dictate, and you could be hard pressed to deal with war, both external and internal.
This vassal-liege relationship is one of the biggest dangers of succession. If your heir is not well-liked by his new subjects he could end up with near no military power and if pretenders rise he might not be able to subdue them. You thus have to attempt to make your heir as suitable as possible, and strike a good balance between levy law and opinion so that you'll have the military power you need in times of crisis.

The Control Aspect
Vassals will not always like their liege. As described above this hurts the liege both economically and military, but there's one final aspect to the vassal-liege relationship: The vassal attempting to end it.
If a vassal is pushed too far, or he's simply too ambitious, he will rise in rebellion against his liege, and forcefully attempt to gain what he wants, be it independence, reduced crown authority, or the liege abdicating. Do note that only direct vassals can rebel, you're thus safe from the ire of your vassals' vassals.
A vassal's chance of rebellion is affected by several factors that are added together, rather than multiplied. The base chance is 0%, and the factors modifying it are:

• Negative Opinion - Increases chance of rebellion by as many percent
• Positive Opinion - Decreases chance of rebellion by half as many percent
• Shared Culture - Decreases chance of rebellion by 15%
• Shared Religion - Decreases chance of rebellion by 15%
• De Jure Liege - Decreases chance of rebellion by 15%
• Pretender - Increases chance of rebellion by 50%
• Distance - Increases chance of rebellion
• Crown Authority - Modifies chance of rebellion by -20% to 20%, increasing by 10% per level

Thus as long as you are someone's rightful liege and share culture and religion, rebellion is unlikely.

Tactics
Your goal in CKII will due to the above be to keep as many nobles as possible happy, as this is how you get your power. You have many means available.

One way to keep your nobles happy, is by bribing them. By giving a noble a lump sum of gold you will increase his opinion of you by 20 for 5 years. Sometimes this can make the difference between surviving a succession or not, or between winning a war and defeat.

A second way to make nobles happy, is by granting them honorary titles. You have the ability to grant 2 honorary titles increasing opinion by 15, and 4 increasing opinion by 10, 2 of which can be given to both genders. Honorary titles and their opinion modifier persists until death.

Third, you can grant your vassals landed titles. This will increase their opinion of you by 20 to 100 depending on the tier of the title, and the effect will persist for 10 years.

Fourth, you should only grant titles to persons who share your religion and your culture. Together this will reduce their chance of rebellion by 30%, and you'll avoid the infidel/heretic and foreigner penalties.

Fifth, never give anyone but your heir more than one county and more than one duchy. As long as you keep your vassals small, it will be near impossible for them to challenge your power.

Sixth, try to keep your realm's titles within your dynasty. Your dynasty will generally be both the same religion and culture as you, and you get 5 extra opinion with all members of your dynasty.

Seventh, keep your capital in a central location if possible. This will minimize the distance modifier, making rebellion less likely.

Eight, don't put crown authority higher than you can handle. Every step up increases the chance of rebellion directly by 10%, and reduces all your vassals' opinion of you by 10.

Ninth, you should try to hold all the de jure titles for the tier (E.G., duke) you're at for the area you rule. While this means you'll have to deal with the occasional 'desires x title', the -15% to rebellion and the prestige you gain from holding the title is well worth it.

Tenth, form and give out duchies. You'll get huge amounts of prestige, which will increase all noble's opinion of you by up to 20. Keeping your realm's titles within your dynasty means your dynasty's prestige will increase, and your children will start out with more prestige, meaning your heir will start out with considerably higher opinion from his vassals upon your death.

Finally, whenever someone rebels you can as long as you have limited crown authority or above, revoke a single title from them after white peacing or enforcing demands. Use this to keep your nobles balkanized. In times of peace you could deliberately piss off a powerful noble into rebellion, then revoke his primary title after beating him so as to split up his power. You can also revoke the titles of infidels and heretics at any time if you have medium crown authority or above, letting you balkanize their holdings, and giving them to your dynasty instead.

Summary
Keep your vassals happy, and they'll keep you strong. Let them get too strong and unhappy, and they'll undo everything you've achieved. My tips are as follows:

• Bribe powerful and unhappy vassals
• Give out honorary titles to powerful and unhappy vassals
• Give out landed titles as a last resort
• Avoid giving titles to infidels and heretics
• Avoid giving titles to those not of your culture
• Never give someone more than one county and one duchy
• Try to keep your realm's titles within your dynasty
• Keep your capital in a central location
• Don't put crown authority too high
• Hold all de jure titles for the area you rule if possible
• Form all duchies and give them to your dynasty members
• Revoke titles whenever it doesn't incur tyranny

 

[Meneth]

Construction; Where, When, and What
First posted here.

If you want a summary without any of the thought behind it, just scroll to the end. If not, read on.
In Crusader Kings II you can construct buildings in your county capitals, and in any holdings in the county that belong to your direct vassals.
Construction is a long-time prospect, as it will take very long for most buildings to pay off. As it works on such a large timescale, quite a bit of thought should be put into what you build, where, and when.

Where
When constructing buildings, your first priority should be your capital. The reasons for this are two-fold.
First, your capital will almost always be inherited by your heir, even if you're using Gavelkind succession. This is important, as buildings often won't pay back the investment within a single character's reign.
Second, your capital will generally have the highest tech level of your holdings, and many technologies enhance the output of your buildings, thus buildings in your capital will repay your investment faster.
Second, you should focus on your own holdings, not your vassal bishoprics and cities. Your own holdings give you their entire income, while vassals will only give you a percentage. In addition, the benefit you get from your vassals is also subject to change in the long term due to changes in opinion, while your own holdings are unaffected.

What
Your focus should be on improving your economic situation. The higher your income, the faster you can construct or upgrade your buildings, so while at first you'll lag behind on the military front you will quickly catch up once your economic buildings repay their cost.
After you have reached decent economic capital, with at least Castle Villages in all your holdings, you should go onto upgrading your military capabilities. At this point you should have a pretty high income, so this should be relatively quick to do. As before, concentrate on your capital holding first, then go onto other holdings.
For each military building you construct, your personal military capacity increases, and this capacity will be there for you even in times of crisis, and as such gives you a base military capacity at all times, thus vastly improving your capabilities during civil wars and also helping you in both defensive and offensive wars.

When
In general, you want to upgrade your holdings as fast as you can. The quicker you build the sooner your investment is repaid, and the more you can construct in the future as well.
However, you should always keep a reserve. How large this reserve should be depends on your size. Essentially you should imagine the worst possible economic scenario that could happen to your realm, and keep that much money or more in reserve at all times. As a small realm like say, Scotland, having 50 gold in reserve at all times would likely be enough most of the time, but it wouldn't be enough if you suddenly needed to hire mercenaries. As such I would recommend a reserve of 100g at the very least for any realm, as then you'll be able to recruit a band of mercenaries and pay their upkeep for almost four months through your reserve alone.

The Math
For the economical buildings, the return on investment is easily calculated.
For the castle town buildings, you get these numbers:

• Level 1, cost 100, income 1.5 - 67 years
• Level 2, cost 120, income 2.0 - 60 years
• Level 3, cost 200, income 2.5 - 80 years
• Level 4, cost 300, income 3.0 - 100 years
• Level 5, cost 400, income 3.5 - 114 years

As you can see, level 2 pays of faster than level 1, but more slowly than level 3. As such, your first goal should be level 2 in all holdings before you upgrade any further.
For the castle wall buildings, you get these numbers:

• Level 1, cost 50, income 0.2 - 250 years
• Level 2, cost 50, income 0.2 - 250 years
• Level 3, cost 100, income 0.2 - 500 years
• Level 4, cost 150, income 0.2 - 750 years
• Level 5, cost 150, income 0.5 - 300 years

On an economical level, only the first two levels will pay of during the duration of a single campaign, so any level beyond that is not worth it on just an economic level, but their other benefits do of course make them worth it.
Now, what also has to be taken into account is that for any town level after 1, you need a certain level of wall, thus giving you these numbers:

• Level 1 town, level 0 wall, cost 100, income 1.5 - 67 years
• Level 2 town, level 1 wall, cost 170, income 2.2 - 77 years
• Level 3 town, level 2 wall, cost 250, income 2.7 - 93 years
• Level 4 town, level 0 wall, cost 300, income 3.0 - 100 years
• Level 5 town, level 0 wall, cost 400, income 3.5 - 114 years

Note that the last two levels of towns do not need further wall upgrades. With wall upgrades taken into account we now get a gradual progression for how long it takes to get a return on your investment, which thus shows us that aiming for level 1 first in all your holdings, then going to the next level and so on, makes the most sense.

Vassal holdings
Due to you only getting a percentage of your vassal's income and levies, your own holdings should usually be prioritized. For castles, your own holdings are always higher priority, as they give the exact same benefits except in full.
While cities give higher revenue per town building than castles, you'll still get less overall due to only getting a percentage of the income.
Churches and cities however have one building each that can be useful: the monastic school and the university. The monastic school increases your tech growth in the province by 10% at level 1, and 20% at level 2, for a total of 30%, while the university increases tech growth by 20% at level 1 and 30% at level 2, but level 2 comes quite late in the game. This can make a major difference in the long run, so if you favor a tech-based approach to the game, investing in this building can be a good idea.

A Few Notes
As long as you have good stewardship, the break-even point for construction will be considerably sooner, as you get 2% more demesne income for every point of state stewardship beyond 5. Thus, at 30 state stewardship, you'll get 50% higher income, reducing the time to reach break-even by one third.
If your succession laws are gavelkind, try to keep your buildings concentrated in your capital duchy, as any other duchy could end up getting inherited by someone other than your heir. Building up a county and then losing it 20 years later due to gavelkind isn't too great an idea.
You can also build new holdings in a county if there are free holding slots. Doing so costs 400 gold, plus 100 gold per holding already in the county. Thus, the lowest possible cost is 500 gold. Cities can bring in quite a bit of money, at a base rate of 12 gold per year. However, even on harsh taxes this will take 75 years to repay itself, and is thus seldom worth it for the gold alone. However, constructing cities or temples does bring the added benefit of more tech growth slots, letting you speed up tech growth even more.
Castles will repay themselves in 166 years, and are as such not worth it for the money alone. Build new castles only if you've maxed out all your other holdings.

Summary

• Build in your capital first
• Don't build anything in your vassal holdings, except for monastic schools as long as you have places left to build elsewhere
• For any specific building type, get it to the same level in all your holdings before going to the next
• Prioritize economic buildings over military buildings
• Always keep a reserve of at least 100g, and preferably more
• If you're under gavelkind succession laws, keep your construction within your capital duchy as much as possible

 

[Meneth]

Technology; Why and How
First posted here.

Much like construction, technology is a long-time prospect. Unlike construction however making progress in technology takes decades, and the effects are tiny in comparison. I'll go into how technology works, and what you can do to maximize your benefit from it.
If you can't be bothered to read all of this, there's a summary at the end.

What It Does
The basics of how technology works in Crusader Kings II is rather simple, but not immediately obvious. Technology works on a per county basis; technology in one county will not directly benefit any other counties.
For every whole level of a technology, you'll get a benefit in that county. There are a variety of effects, and these will be gone into in a later section.

How It Spreads
Technological progress happens based on percentage chances. Every month you have a percentage chance of making progress for each tech for each county, measured on a per year basis. Through a dice roll you either make progress towards the next level, or remain where you were before.
Each time the dice roll succeeds, your technological level for that specific tech in that specific county increases by 0.1.
Once the technological level reaches a whole number, you gain the benefit from that level; you don't get say 50% of the effect of level 2 if you're at 1.5, you get the effect of level 1.
Most of your tech will be achieved through the dice rolls mentioned earlier. The percentage chances in a county are affected by several conditions:

• What year it is
• State attributes
• Tech focus
• Councillor missions
• County buildings
• Other counties

All of these factors are multiplied together to decide the final percentage. The base percentage is always 1.2% per year, but this can be increased to much higher levels.

The Effects
There are in total 24 different technologies, 8 for each major area: Military, Economy, and Culture. The effects are as follows:

Military:

• Bows - Increases the attack stats of archers and horse archers by 10% at level 1, increases by 5% per level
• Light Armour - Increases the armor stats of Light Infantry, Light Cavalry, Archers, and Horse Archers by 10% at level 1, increases by 5% per level
• Heavy Armour - Increases the armor stats of Heavy Infantry, Heavy Cavalry, and Pikemen by 10% at level 1, increases by 5% per level
• Infantry Melee Weapons - Increases the attack stats of all infantry by 10% at level 1, increases by 5% per level
• Cavalry Melee Weapons - Increases the attack stats of all cavalry by 10% at level 1, increases by 5% per level
• Siege Equipment - Increases siege speed by 10% at level 1, increases by 10% per level
• Military Fortifications - Decreases enemy siege speed by 10% at level 1, increases by 10% per level
• Tactics - Increases morale by 0.1 at level 1, increases by 0.1 per level

Economy:

• Farming - Increases castle tax by 10% at level 1, increases by 10% per level
• Trade Practices - Increases city tax by 10% at level 1, increases 10% per level
• Church Taxes - Increases church tax by 10% at level 1, increases 10% per level
• Castle Infrastructure - Unlocks castle buildings
• Town Infrastructure - Unlocks city buildings
• Temple Infrastructure - Unlocks temple buildings
• Improved Keeps - Unlocks walls, moats, and garrisons
• Construction - Reduces construction time by 5% at level 1, increases by 5% per level

Culture:

• Noble Customs - Increases opinion of nobles by 3/6/8/10/12
• Popular Customs - Increases opinion of burghers by 3/6/8/10/12
• Religious Customs - Increases opinion of priests by 3/6/8/10/12
• Majesty - Increases prestige gain by 10% at level 1, increases by 10% per level
• Spiritual Art - Increases piety gain by 10% at level 1, increases by 10% per level
• Cultural Flexibility - Reduces the 'Foreigner' modifier by 10% at level 1, increases by 10% per level
• Religious Flexibility - Reduces the Infidel/Heretic modifiers by 10% at level 1, increases by 10% per level
• Legalism - Reduces the length of 'Short Reign' by 1 year at level 1, increases by 1 per level. Increases demesne size by 1 per level; every level for kings/emperors, every level but 3 and 5 for dukes, level 1 and 3 for counts, level 2 for barons

What To Research
Now, the culture techs are special in that they only affect you if your capital county has the technology. A low or high tech outside your capital will not hurt or help you directly in any way.
The culture techs are also, arguably, by far the most useful techs, especially the customs techs and legalism. Both let you more easily manage a large realm, and makes succession easier. The flexibility techs are also useful if you expand into areas with different culture or religion than your own, and thus end up with foreign vassals.
So for the culture techs, I would recommend focusing on legalism if you're a king/emperor as it will make succession so much easier both by giving you a larger powerbase, and by decreasing the short reign penalty. Second I would focus on Noble Customs as that will affect pretty much everyone in your realm with any real power.
For the economy techs, the two most important ones are Farming and Castle Infrastructure. Farming directly increases your income from a holding by 10%, while Castle Infrastructure will let you build further buildings, giving you access to more income and more levies.
For the military techs, Tactics is quite useful as it affects all your units. Beyond that you should probably just concentrate on whatever unit(s) you get from your culture's unique building.

How To Maximize Technological Growth
First off, don't try to get too far ahead of the curve, as you'll get a large 'ahead' penalty towards technological growth if you do so. Instead, try to just keep a few decades ahead of opposing realms.
Second, try to get as good councilors as you can, and especially your Court Chaplain. Your state learning (your own stat + your councilor's stat + half your spouse's stat) plus the state stat for the relevant area will increase technological growth in that area by as many percent. This can make a huge difference in how fast you achieve technological growth.
Third, use your tech focus to get what you want, and switch once you've achieved that level. It also benefits you to boost techs that are nearing the next level, as this will fuel tech growth in the rest of your demesne.
Fourth, focus on your capital. As the entire culture branch works based on your capital, there is no real point in encouraging cultural tech elsewhere.
Fifth, build the tech buildings in your capital. By upgrading the Monastic School and University in your capital county, you can easily achieve 50% higher technological growth there.
Sixth, use your councilors whenever they're available. Have them boost tech growth in your capital. They'll increase tech growth in that county by 5% per level they have in the relevant skill.
By concentrating entirely on your capital, you'll also be indirectly increasing tech growth in the rest of your realm as well. Neighboring a county with a higher tech level will increase tech growth by 15% per county, and having a county with a higher tech level in the same demesne will also increase tech growth by 25% per county. Thus, when you achieve a higher level in your capital you'll increase tech growth in your entire demesne for that tech by 25%, and by another 15% for any county your capital borders.

Summary
By maximizing technology you can get the edge you need to survive against the odds, and to deal with bad successions. Investing early in technology can benefit you for the entire length of a campaign, and can bring large benefits.

For those who cannot be bothered to read everything, just remember this:

• Concentrate on your capital
• Focus on Legalism, Noble Customs, Farming, Castle Infrastructure, and Tactics
• Get as good councilors as possible
• Use your councilors to boost tech growth in your capital
• Build tech buildings in your capital
• Utilize your tech focus

 

[Meneth]

Succession Laws; Pros and Cons
First posted here.

Succession laws are extremely important in Crusader Kings II, as they control who gets what land, and control multiple opinion modifiers. I'll go into the advantages and disadvantages of each system. There's a summary at the end.

Succession Laws
There are seven different succession laws, but in practice the player can only use four of these. The seven are as following:

• Gavelkind, the titles of the ruler are divided between his eligible children
• Seniority, the oldest eligible member of the dynasty inherits
• Primogeniture, the oldest eligible child of the ruler inherits
• Feudal Elective, the ruler and every vassal one step under (unless it is an empire, then it extends two steps) him can nominate amongst themselves and the ruler's eligible children. Whoever gets the most nominations inherits.
• Open-Agnatic/Turkish Succession, whoever in your dynasty holds the best titles inherits. The player cannot use this.
• Catholic Bishopric, the pope or the ruler (depending on the investiture laws) decides who inherits. The player cannot use this.
• Open Elective, like feudal elective, except every vassal and courtier gets a vote. The player cannot use this.

Now, each of these laws give various benefits, and also various drawbacks, and I'll go through them one by one.

Gavelkind
Gavelkind has one large advantage: Your demesne can be 30% larger. If you could normally have a demesne 8 holdings large for example, you'd with gavelkind be able to hold 10 holdings without any problems. This can make expansion easier as you don't have to immediately give up gained titles to your vassals, you can instead hold onto them until you have a suitable vassal to give them to.
It also gives 30 extra opinion with every eligible heir except the oldest, 10 opinion with the rest of your dynasty, and 5 with every other vassal.
Gavelkind does however have a rather major drawback. As your titles will be distributed between your children you will almost always end up with fewer titles upon succession, and if you hold multiple kingdoms your realm will be split. It also gives you -10 opinion with your oldest eligible heir.
One workaround for this is to ensure that there is only ever one eligible heir, and this can be done in a few different ways.
The first one, and the simplest one, is making any extraneous heirs bishops as bishops cannot inherit. This is however only possible if you have any bishoprics to grant.
Second, you can assassinate or banish any extraneous heirs. The first however has the drawback of risking the Kinslayer trait which reduces your relations with your entire dynasty and reduces your diplomacy stat, while the second induces tyranny and thus makes every vassal you have angry.
Third, you can ensure that no more than one heir is ever born, either by getting the celibate trait, or by killing your wife. The first method is far from surefire, while killing your wive risks you getting Kinslayer.
A major drawback of the 2nd and 3rd methods are that if your primary heir somehow dies before you do, you're now left with no heirs. Unless you then manage to get another heir in time or change succession laws it would be game over.

Seniority
With seniority the oldest eligible member of your dynasty will inherit. You'll need Medium or higher crown authority to change to it.
This succession law brings several advantages:
*You get an opinion boost (+10) with every member of your dynasty except your first-born eligible heir * There is almost never a shortage of heirs * You can use this to consolidate dynasty-held titles
As there are so many heirs, game over due to not having a dynasty heir is extremely unlikely. The opinion boost reduces the chance of succession crisis, as your potential heirs will be less likely to rebel to try to get the throne.
A rather clever use of seniority succession, is to consolidate multiple titles held by the same dynasty but different characters, to a single character that you control. By switching your own succession laws to seniority, the person inheriting your titles will eventually be one that holds other titles as well, and these titles will thus now be held together with your own by a single character.
This tactic can be especially useful for the Spanish kingdoms and the Russian duchies, as they are all held by a single dynasty.
Seniority succession does however also have its disadvantages. The most obvious, but also relatively minor, disadvantage is the opinion loss you get with your first-born eligible heir (-30) and your other children (-20). The more major disadvantage however is that almost every time you die and another character inherits, that character will already be quite old. Thus, with seniority you end up having very many reigns, but very short ones. You'll thus have to near constantly deal with the short reign penalty, and can lead you to a state of near constant peacekeeping as your vassals are much more likely to rebel from a new king than someone who've reigned for long, and you will almost never get the chance to reign for very long.
Another, but not as major, disadvantage is that now you'll have possibly dozens of potential heirs all gunning for the throne, and assassinations within your dynasty become much more likely as characters try to be the oldest remaining member.
You'll also get a small negative opinion modifier (-10) with all your non-dynasty vassals, so if you use seniority you should try to keep the titles in your realm within your dynasty as much as possible.

Primogeniture
With primogeniture succession, the oldest eligible heir inherits, and you need High or Absolute crown authority to it. Primogeniture has certain advantages:

• You get 20 higher opinion with your oldest eligible heir
• You can more easily control what traits your heir has
• The title always stays in your dynasty as long as you have eligible heirs

Personally I consider the degree of control you get with primogeniture its main advantage. As you know who will inherit, it is much easier to groom this heir to be a worthy successor, most prominently by being your heir's guardian.
Unlike seniority, your heir will also usually be young, so you'll end up with long reigns and will thus get the opportunity to act beyond the initial unrest after a succession. You also, unlike with gavelkind, get to easily hold onto all your titles.
But, as with any succession law, primogeniture has its drawbacks. Every eligible heir you have beyond your first is a potential pretender, and as such succession crisis is more likely. You also get a -20 opinion modifier with all your eligible heirs except for the oldest, and -5 with every other member of your dynasty.
As with seniority, you get the issue of heirs killing each other off in an attempt to gain the throne, sometimes even killing you to get it. You also have a much smaller pool of heirs than with seniority or elective, and you're therefore more likely to get game over. If you're unlucky you could also end up with a really bad heir with little you can do about it beyond assassination or priesthood.

Feudal Elective
Finally, you have feudal elective. With feudal elective succession law every vassal one step below you (E.G., counts if you're a duke) (unless you're an empire, then it extends two steps) get a vote on who inherits, and they can choose from amongst themselves and your eligible children. Every vassal gets a single vote no matter if they hold one duchy or twenty. If there's a tie, your vote takes precedence. If the tie is between two characters you didn't vote for, the person with the highest titles voting takes precedence.
This has the advantage of you being able to choose who specifically inherits your titles. It also gives you a large opinion boost of 20 with all your vassals.
The potential drawbacks for elective succession are quite big. You get -30 opinion with your oldest eligible heir, -10 with every other, and -5 with the rest of your dynasty.
You also have far from complete control over succession, as your vassals can overrule you and vote for someone else than your designated heir. This can lead to someone outside your dynasty inheriting, and thus to either game over or you being left only with your non-elective titles.
These features makes elective quite effective if you have good control over your vassals, and it has high rewards in that you can specifically choose who inherits without having to risk Kinslayer. It also has high risk, and a single untimely death could lose you a lot.

Gender Laws
The other part of succession are gender laws. There are three different gender laws to choose between; agnatic, agnatic-cognatic, and absolute cagnatic. These laws decide what sex can inherit. The effects are as follows:

• Agnatic, only males can inherit
• Agnatic-cognatic, females can inherit as well, but only if there are no eligible males
• True cognatic, females inherit on equal ground as males

Agnatic
With agnatic succession, which many titles start as, only males can inherit. This has the advantage that you will never have female pretenders, as they aren't eligible. You will also almost never lose the game by your heir not being of your dynasty as the only way that can happen is that you have no eligible heirs, through elective, or through matrilineal marriage.
The disadvantage is of course that if you have in primogeniture no male children, nor close dynasty members it is game over upon your death, and in gavelkind if you have no male children. Thus, you could more easily lose the game with agnatic succession.
You will also get -10 opinion with all female members of your dynasty.

Agnatic-cognatic
With agnatic-cognatic succession females can inherit, but only if there are no eligible male heirs. This makes it entirely pointless to have it in combination with elective or seniority as you will always have eligible males, and the only thing you'll get out of it is losing the opinion penalty with female members of your dynasty, while gaining the potential for female pretenders.
Therefore, you should only ever use cognatic-agnatic succession together with primogeniture or gavelkind, as then it'll give you an extra chance of survival if you have no male heirs.
The drawback is that you can then get female pretenders, and your male vassals will get -10 opinion with you if your heir is female, or you yourself are female. You could also end up losing due to a female married patrilinealy inheriting, as her children will not be of your dynasty, making you lose if they inherit. The only way around it if it happens is remarrying matrilinealy and making the original children ineligible through priesthood or death, or changing succession law to elective or seniority.

Absolute cognatic
Finally, you have absolute cognatic succession. This makes females inherit on the same grounds as males, and thus works with every type of succession. However, you can only implement this if your culture is basque, so you're unlikely to ever have this succession type unless you're playing as one of the Spanish factions.
The main advantage of absolute agnatic succession is double as many potential heirs, which can be used in conjugation with elective for even higher control over who inherits. It is also of course interesting for roleplaying purposes.
It is however not very useful for gameplay purposes, as it will give you -10 opinion with any male member of your dynasty, and another -10 with all your vassals if your heir is female or if you yourself are female. As with cognatic-agnatic you have many more potential pretenders than with agnatic, and problems if a patrilineally married woman inherits.

Summary
Overall every single type of succession has both advantages and drawbacks, and it is thus a matter of choosing the risk and control levels you yourself prefer.

• Gavelkind has the advantage of a large demesne, but your titles will easily get split up. Your dynasty and junior heirs like this, and it will make your vassals a bit happier. You're much more likely to get game over due to having no eligible heirs than any other system.
• Seniority can be used to consolidate titles, and makes your dynasty happy. You'll almost never get a game over due to no eligible heirs or inheritance outside of the family. However, all your heirs will be old, so you have to deal with succession constantly. It also makes your own children unhappy, and your vassals.
• Primogeniture gives you more control over the development of your heir as you can tutor him/her. It makes your oldest eligible heir happy, but pisses off the rest and makes your dynasty members slightly unhappy. You're also more likely to get game over due to no eligible heir than seniority and elective.
• Elective gives you a high degree of control over who inherits, but your vassals can overrule you, even giving you game over by having someone outside your dynasty inherit. This law makes your vassals happy but pisses of your children and makes your dynasty members a bit unhappy.
• Agnatic succession avoids the risk of your female heirs marrying patrilinealy, but you're more likely to have no eligible heirs in primogeniture and gavelkind succession. Makes female members of your dynasty unhappy
• Cognatic-agnatic succession gives you a higher chance of having an eligible heir for primogeniture and gavelkind. Doesn't work with elective and seniority. You might end up losing due to your female heir having married patrilineally. Having a female heir pisses of your male vassals.
• Absolute cognatic is only useful for roleplaying purposes as it pisses of your male dynasty members, and having a female heir is generally worse than having a male heir due to how patrilineal marriages work and the penalty for being a female ruler or having a female heir.

 

[Meneth]

Taxation; Workings and Maximization
First posted here.

Taxation is how you get your money in Crusader Kings II, and is thus an important feature to understand. I'll go into how taxation is calculated, and how to gain the greatest economical benefits. As always, there's a summary at the end.

The Basics
How much tax is paid depends on three factors:

• Holding income
• Tax law
• Opinion towards tax recipient

These three factors are multiplied together to decide the tax paid.

Holding income
Holding income is quite simple. It is calculated by adding the income of all buildings in an income to the base income of that holding. The base income is 3 for a castle, 8 for a temple, and 12 for a city.
This income is then multiplied by any additional factors, primarily the Farming/Trade Practices/Church Taxes technologies and the Steward's Collect Taxes missions. In addition there are some events that can affect the income of a holding, but they're rather self-explanatory.

Tax Law
Each type of holding has its own type of tax law. However it is worth noting that the tax a vassal pays is not in fact based on the type of holding, but the type of noble they are. For example if someone owns a city and a castle, and is a count he'll be paying the tax level decided by Feudal Taxation, not City Taxation.
The multiplier can vary from 0 to 1, but for your vassals the max is 0.55. The full list is below:

Nobles:

• No Feudal Tax - 0
• Small Feudal Tax - 0.1
• Large Feudal Tax - 0.2
• Harsh Feudal Tax - 0.3

Burghers:

• Minimal City Taxes - 0.15
• Normal City Taxes - 0.25
• Large City Tax - 0.35
• Harsh City Tax - 0.45

Clergy:

• No Church Tax - 0
• Minimal Church Tax - 0.35
• Medium Church Tax - 0.45
• Large Church Tax - 0.55

Your demesne however always has a multiplier of 1, so unless you're paying tax to anyone above you you get to keep it all.

Opinion
If a tax payer's opinion towards the tax recipient is under 0, tax paid will be reduced by as many percent. Thus at 0 or above opinion they'll pay full tax, at -50 they'll pay half tax, and at -100 they'll pay no tax.
Your opinion towards yourself is always counted as a multiplier of 1.

Indirect Taxation
You will also get a portion of any tax paid to your vassals, the same portion (in percent) as you get from their demesne income. This is generally a trivial amount unless they have a lot of vassals, though.

Calculation
Thus the full formula for tax becomes this:
(TheirTaxIncome + (BaseIncome + Buildings)) * HoldingIncomeFactors * TaxLaw * OpinionModifier
For your own holdings it is simply this as both TaxLaw and OpinionModifier are equal to one.
(BaseIncome + Buildings) * HoldingIncomeFactors

Maximization
Now that we know how tax works and what effects it, we can now work out how to maximize it.
First we've got simple construction, which will directly increase the income of a holding, which will trickle down as tax. As I detailed in this post, constructing buildings in your vassals' holdings gives less of a return on your investment than building in your own demesne. As such when seeking to maximize income you should build as many income buildings in your demesne as possible.
Second, you can up the tax law to make your vassals pay more. However if their opinion is already low enough this will not pay off, with a full list here:

• 10% -> 20% gives more as long as opinion is originally above -80 (0.1 * 0.2 = 0.2 * 0.1)
• 15% -> 25% gives more as long as opinion is originally above -75 (0.15 * 0.25 = 0.25 * 0.15)
• 20% -> 30% gives more as long as opinion is originally above -70 (0.2 * 0.3 = 0.3 * 0.2)
• 25% -> 35% gives more as long as opinion is originally above -65 (0.25 * 0.35 = 0.35 * 0.25)
• 30% -> 40% gives more as long as opinion is originally above -60 (0.3 * 0.4 = 0.4 * 0.3)
• 35% -> 45% gives more as long as opinion is originally above -55 (0.35 * 0.45 = 0.45 * 0.35)
• 45% -> 55% gives more as long as opinion is originally above -45 (0.45 * 0.55 = 0.55 * 0.45)

As such, higher tax will almost always equal more income, but this does not take into account the hit to levies, nor the chance of rebellion.
Third, you can do what you can to keep all vassals above 0 opinion. Granting them titles, running tournaments, granting their wishes, making them councilors, etc.
Finally, we've got one special case: Clergy. Clergy will only ever pay you tax if they prefer you over the pope, and as their opinion towards the pope is generally in the 40 to 60 area getting them to like you more than the pope can be pretty hard. One extremely effective workaround is appointing an anti-pope. You will get all church taxes paid to the antipope, so every bishop who likes either you or the antipope more than they like the real pope will pay you church taxes. In addition, every bishop in the realm will pay tax to you if they like the antipope more than they like the real pope and their liege. If you rule a large realm church taxes could therefore end up as your largest source of income.
For example in my Scotland campaign where I controlled all of the British Isles except a small area in central England, I got about 400 gold a year in church taxes, while the rest of my income amounted to about 100-150 gold.

Impact on Other Areas
While maximizing income is pretty simple, it can have a drastic effect on other areas of your realm. Increasing taxes will make your nobles like you less, and thus make them more likely to rebel and give you less levies. Too high taxes can thus make your realm considerably weaker, and massively increase internal turmoil. You can thus easily end up spending more time and money on placating your vassals and putting down rebellions than you earn in increased income.
So while you might end up earning more money, if you're not careful you'll never actually get to use that extra money for anything useful, instead using it up in unit upkeep and bribes.

Summary
Through several different methods you can increase your income, but if you're not careful you won't get any use out of it.

• Construct buildings. More info here
• Find a suitable tax level. Balance it between good opinion and high taxes.
• If you get the opportunity, appoint an antipope.
• Research relevant technology. More info here

 

[Meneth]

Levies; Inner Workings and Maximization
First posted here.

In Crusader Kings II, most of your military is based around levies. At the time few had anything resembling standing armies, instead drafting peasants in times of war. As levies are core to your ability to defend yourself, understanding how to get as many as possible is important. I'll therefore be going into how levies work, and what you can do to get more.
As always, there's a summary at the end.


The Basics
How many levies you can raise depend on three factors:

• Holding levies
• Levy and crown law
• Opinion towards liege

These three factors are multiplied together to decide how many levies you can raise.


Holding Levies
This is quite similar to holding income, except with soldiers instead of gold. It is calculated by adding the levies of all buildings in a holding to the base levies of that holding. The base levies are 60 light inf, 150 heavy inf, and 15 cavalry for castles, 75 light inf and 40 archers for cities, and 45 light inf, 45 heavy inf, and 40 archers for temples.
The total levy is then multiplied by any additional factors, most notably the buildings that increase levy size, but the Marshal also has a mission that increases levy size, and certain events can increase it as well.

Levy Law
Each type of holding has its own type of levy law. Like with tax law this is based on what type of vassal the vassal is, not the holding itself. For example if someone owns a city and a castle, and is a count his levies will be based on Feudal Levies, not City Levies.
Like with tax this multiplier can vary from 0 to 1. The full list is below:

Nobles:

• Min Feudal Levies - 0.6
• Small Feudal Levies - 0.7
• Normal Feudal Levies - 0.8
• Max Feudal Levies - 1

Burghers:

• Minimal City Levies - 0.5
• Normal City Levies - 0.65
• Large City Levies - 0.8
• Max City Levies - 0.95

Clergy:

• Minimal Church Levies - 0.5
• Normal Church Levies - 0.6
• Large Church Levies - 0.7
• Max Church Levies - 0.8

Like with tax, your demesne always has a multiplier of 1.

Crown Law
Crown law decides the minimum levy your vassals have to provide you. Even if due to other factors they want to give you less than the minimum, they'll still have to give you the minimum as long as they have levies available. The full list of minimums are as follows:

• Autonomous vassals - 0% minimum
• Limited crown authority - 10% minimum
• Medium crown authority - 20% minimum
• High crown authority - 30% minimum
• Absolute crown authority - 40% minimum

Opinion
For any opinion below -25, you will only be able to raise the minimum levy as described above. The higher their opinion above -25 the more they'll want to provide, with 0 at -25 and 100% at 100. As such for each point of opinion they'll want to provide 0.8 percenta more of their levies.
Your opinion towards yourself is always counted as a multiplier of 1.

Calculation
Thus the full formula for tax becomes this:
(BaseLevy + Buildings)) * HoldingLevyFactors * LevyLaw * OpinionModifier
For your own holdings it is simply this as both LevyLaw and OpinionModifier are equal to one.
(BaseLevy + Buildings) * HoldingLevyFactors

Maximization
With this understanding of how levies work we can figure out how to get the most out of it.
First we can, as with taxes, construct buildings, which will directly increase the levies of a holding, part of which you'll be able to raise. However, like with tax, you'll get a much higher return on investment if you build in your own demesne, as then you can raise your full levy capacity. The drawback is of course that you then have to pay upkeep, but you won't be pissing your vassals off.

Second, you can up the levy law to make your vassals pay more. However if their opinion is already low enough this will not pay off, with a full list here:

Nobles:

• Min -> Small gives more as long as opinion is at 10 or above
• Small -> Normal gives more as long as opinion is at 15 or above
• Normal -> Max gives more as long as opinion is at -5 or above
• Max -> Normal gives more as long as opinion is below -10
• Normal -> Small gives more as long as opinion is below 10
• Small -> Min gives more as long as opinion is below 5

Burghers:

• Min -> Small gives more as long as opinion is at 18 or above
• Small -> Normal gives more as long as opinion is at 28 or above
• Large-> Max gives more as long as opinion is at 38 or above
• Max -> Normal gives more as long as opinion is below 28
• Large -> Small gives more as long as opinion is below 18
• Small -> Min gives more as long as opinion is below 8

Clergy:

• Min -> Small gives more as long as opinion is at 35 or above
• Small -> Large gives more as long as opinion is at 45 or above
• Large -> Max gives more as long as opinion is at 55 or above
• Max -> Large gives more as long as opinion is below 45
• Large -> Small gives more as long as opinion is below 35
• Small -> Min gives more as long as opinion is below 25

In case anyone cares, here's the math I used for this: (5/4 * (OriginalLevy% * x = NewLevy%(x - (OpinionChange/100 * 4/3))) * 100 + 25
For the reductions I simply took the value the above formula gives, minus the opinion change.
As you can see, raising levy law will only ever help you if your vassals already like at least somewhat. As such, running high levy laws is not always a good idea. However, at these opinion numbers you're unlikely to hurt any other aspect of your realm, so as long as you benefit levy-wise from raising levy law, you probably should.
Third, you can do what you can to keep all vassals above -25 opinion. Granting them titles, running tournaments, granting their wishes, making them councilors, etc. Each point of opinion will increase the percent they're willing to give by 4/5.
Fourth, you will only ever benefit levy-wise from crown law if you were already getting below the new minimum percent. For example if you're getting 25% at Medium Crown Authority, and raise it to high, the minimum will now be 30% and you'll be able to raise more levies. If on the other hand you were getting 35% before and you raise your Crown Authority, you'll now be getting 5 percentage point less.

Summary
Levies are easy to get plenty of as long as you have a strong demesne or your vassals like you. Your priorities should therefore be:

• Construct buildings. More info here
• Don't put your levy laws high unless your vassals like. You'll gain no benefit whatsoever.
• You'll only benefit levy-wise from crown law if you're already getting less than the percentage the new crown law would demand.
• Research relevant technology. More info here. This won't give you more levies, but it will make them stronger.

 

[Meneth]

Marriage and Children; Ensuring Your Future
First posted here.

As Crusader Kings II is based around your dynasty, getting the most out of marriage is essential. Marriage is the primary way to expand your dynasty, and to ensure its continuation. In addition, marriage can be used to forge alliances.
I'll go into how the marriage mechanic works, and how you can use it to your benefit.
As always there's a summary at the end.


The Basics
Anyone above the age of 16 can get married. Anyone below 16 can get betrothed. There is no max age at which one can get married, but women become completely infertile at 46, with the exception of certain events (bastards for example)
Marriage brings several benefits, the most obvious of which is child birth. In addition, you also get half of your spouse's stats added to your own for the purpose of state statistics, and for determining demesne size. You'll also get prestige if the house your spouse is from is a prestigious one, and you'll get or lose prestige depending on the rank of your spouse, 20 prestige per step above or below you. So if for example you as an emperor marry a king's daughter, you'll lose 20 prestige while she'll gain 20.
Further there are many events, both good and bad, tied to being married. The traits of your children will also be affected by the traits of your spouse, and you can assign your spouse as spymaster as the position is limited to males, the ruler's mother, and the ruler's spouse.

Children
As long as the female in a marriage is under 46 and neither character has the Celibate trait, she can potentially get pregnant. The chance of pregnancy is affected by several traits, like Chaste and Lustful. It is also possible for her to get pregnant through events, for example if your male character becomes rather angry with the death of his first-born son.
Couples tend to have two children on average, but traits increasing fertility can make a couple produce far more than this. My personal record is 9 children, and I've heard of people having as many as 15. So as long as you don't have any fertility reducing traits, you should be able to get enough children to continue your dynasty.
The stats and traits of a child will be affected by the stats and traits of both parents. As such if you want a good heir it is wise to marry someone with good stats and traits. Do note that a mother will have very good relations with her own children, but not the children from a previous pairing. As such if you remarry and have more children, you risk your new wife assassinating your original children to pave the way for her own.

Statistics
Half of your spouse's stats will be added to your own for most purposes. This includes all the state statistics and your demesne limit.
As your spouse affects your demesne limit, a high Stewardship spouse means you'll be able to hold several more holdings, 1 for every 8 points (s)he has in Stewardship. For reference, you can hold 1 extra holding for every 4 points you have in Stewardship.
If your spouse has higher numbers in any stat, you'll be likely to get occasional events where you'll get the opportunity to ask your spouse for help. This usually gives you a positive temporary modifier to some aspect of your realm, and a 20% chance of getting 1 point in that skill. However, there's also an 80% chance to get the Content trait, which means you cannot get the extremely useful Ambitious trait (+2 to every stat)
Marrying someone with high stats can therefore be very useful, and can make a big difference in how well you're able to control your realm.

Alliances
Marrying someone or their son or daughter, or marrying your son or daughter to them or their son of daughter, will give you an alliance. However, unless they join your dynasty either through you/your son marrying patrilinealy or you(female)/your daughter marrying matrilinealy, this alliance will not persist for future generations. As such, many marriages will only confer a temporary alliance, not a lasting one. As long as a member of your immediate family (your children, grandchildren, siblings, grandparents, and parents) is married to a member of their immediate family, the alliance persists.
If you want a lasting alliance, you'll have to ensure the children are of your own dynasty. The alliance will then persist forever unless a later generation leaves your dynasty.
By marrying your children to other powerful lieges, you'll be able to call these characters into your own wars and thus have them assist you. This is however a two-edged sword as they can do the exact same with you, and if you decline the call to arms you'll get a loss to prestige and take an opinion hit.

Overall Strategy
When you're marrying someone, or marrying your primary heir to someone, your first priority should be good stats and traits. Avoid anyone with big losses to fertility, and anyone above 30, as they'll be much less likely to produce the children you need. Especially seek positive genetic traits, full list below:

• Fair - Gives 30 opinion with the opposite sex, +1 diplomacy. Especially useful if a female heir gets it.
• Genius - +5 to all stats, +5 opinion with all vassals. EXTREMELY good trait
• Quick - +3 to all stats. Very good trait.
• Strong - +1 Diplomacy, +2 Martial, +2 Health, +10% Fertility, +10 opinion with the opposite sex, +10 opinion with all vassals. Extremely good trait.

On the other hand, avoid the negative genetic traits as these could end up plaguing your heirs for generations. Full list below:

• Clubfooted - -10 opinion with the opposite sex, -1 martial
• Harelip - -10 opinion with the opposite sex, -1 diplomacy
• Hunchback - -30 opinion with the opposite sex, -5 opinion with all vassals, -1 martial
• Lisp - -5 opinion with the opposite sex, -1 diplomacy
• Stutter - -1 diplomacy
• Ugly - -20 opinion with the opposite sex, -1 diplomacy
• Dwarf - -30 opinion with the opposite sex, -1 martial
• Slow - -3 to all stats
• Imbecile - -8 to all stats, -10 opinion with all vassals. Extremely bad trait.
• Inbred - -5 to all stats, -30% fertility, -1.5 health, -20 opinion with all vassals. Even worse than Imbecile.
• Weak - -1 health, -5% fertility, -1 martial, -10 opinion with the opposite sex, -10 opinion with all vassals.

When you're marrying off children who won't be your heir, these concerns are far from as important. You should still try to avoid the worst of the genetic traits however, as you don't ever want to be stuck with them.
Your primary priority when marrying off children is instead to expand your dynasty and to gain alliances. If you get the chance, marry your daughters matrilinealy. Try to avoid marrying your sons matrilinealy, as the children being a part of your dynasty is of great benefit, as then the alliance will persist through the generations.
If you get the opportunity to marry in a way that preserves your lineage, not the other dynasty, try to marry the ruler or his/her primary heir, but only if they don't have children already. A second batch of children of your dynasty is far from as useful as primary heirs of your dynasty.
Further, try to avoid marrying people that are already in your dynasty, as then you risk the negative genetic traits. While the risk is very low once you get a few steps away (E.G., second cousins), it generally isn't worth it. So unless you have a very good reason to do so, never marry anyone in your own dynasty. You don't want to end up like Charles II of Spain.

Summary
Through well thought-out marriages you can gain powerful alliances and expand your dynasty, and ensure good heirs. Bad marriages on the other hand could have you end up dead or with an inbred heir. Overall my tips are as follows:

• Avoid marrying within your dynasty
• When possible, preserve your dynasty; marry daughters matrilinealy (if possible) and sons patrilinealy
• When preserving your dynasty, marry rulers or heirs
• Avoid remarrying unless necessary
• Avoid bad genetic traits like the plague
• When you or your heir is marrying someone, find someone with good stats and traits
• The Genius and Quick traits are extremely useful
• If you want children, don't marry anyone above 30 or someone with traits that reduce fertility

 

[Meneth]

Claims and Casus Belli; Expanding Your Realm
First posted here.

In Feudal Europe you needed a reason to go to war. This didn't necessarily have to be a good reason, but without any reason whatsoever, you could not go to war and expect your vassals to support you. A justification for war is known as a casus belli. In Crusader Kings II there are several different types of casus belli, and they can be gained in a multitude of ways. I'll be going into each type of casus belli and how you can attain it.
As always, there's a summary at the end.

The Basics
If you don't have a casus belli against an independent realm, you cannot go to war against it. If you do have one you can go to war, but what happens upon winning, losing, or stalemating the war depends upon the casus belli you are pushing. In any single war you can only push a single casus belli, so you should make sure to push whichever casus belli benefits you the most. With the exception of the Tribal Invasion CB, all CBs incur a 10-year truce. Do note that truces only apply to a specific character, and only the attacker is restricted. So if the attacker or defender dies, the truce is moot, and the defender can attack back at any time.

Claim CBs
Most casus belli, if one discounts rebellion CBs, are based around claims. If you or one of your vassals have a claim upon a title in a realm, you can push this claim through war. If you have multiple personal claims upon a single realm you can push all of them at once with the Push All Claims mechanic. Otherwise you can only press a single claim per war.

If you have a claim upon a title you have a certain 'right' to this title. Upon winning a claim war you, or the person you were pushing the claim for, will gain this title, and if you were pushing it for someone their opinion of you will increase by 100, and you'll gain 100 prestige. If it ends in a stalemate you'll lose 100 prestige, and if it ends in loss, the claim will be lost in addition to 200 prestige. When pushing a vassal's claim and losing you'll have to pay concessions.

De Jure CBs
If you or a vassal hold a duchy or county, where part of this duchy/county is owned by another independent realm, you can push a de jure claim upon one of the counties/holdings held by the other realm. Even if the other realm holds more than one county/holding you can only push a single de jure CB at once. Kingdoms and empires do not provide de jure CBs.
Unlike regular claims, de jure claims cannot be lost unless you lose control of the duchy/county. Losing a war merely means a loss of 200 prestige, while you'll still keep the de jure CB. If you win you'll gain the county/holding as a vassal, or if you were pushing the de jure claim for someone else they'll gain the county/holding as a vassal, have their opinion of you increased by 100, and you'll gain 100 prestige. When pushing a vassal's claim and losing you'll have to pay concessions.

Change Law CBs
There are several CBs based around changing realm laws, both crown and succession law. In total there are five, changing to Gavelkind, Elective, Seniority, or Primogeniture, and lowering crown authority.
The first four can be used on your liege as long as they don't have the succession type in question. The lower crown authority CB can be used on your liege if he's a king or emperor. You cannot use these CBs more than one step up the chain, so if for example you're a vassal of the King of Bohemia you cannot try to lower crown authority in the Holy Roman Empire.
If you win the war, the law in question will be instituted. If you stalemate or lose you'll lose 100/200 prestige.

Independence CB
As long as you're someone's vassal, you can try to achieve independence through war. If you win you'll be independent and if the liege you're rebelling from is a king or emperor, crown authority will be lowered one step. If you stalemate you'll lose 100 prestige, and if you lose you'll be imprisoned and lose 200 prestige. Like with changing law, you cannot use this CB more than one step up the chain.

Depose Liege CB
As long as no one else is trying to depose your liege, and your liege is not attempting to depose someone else or declaring independence, you can attempt to depose your liege. Upon victory crown authority will be lowered by one step (if the deposed liege is a king or emperor), and your liege will depose to the eligible heir you like the most. If you stalemate you'll lose 100 prestige, and if you lose you'll be imprisoned and lose 200 prestige. Like with changing law, you cannot use this CB more than one step up the chain.

Overthrow Ruler CB
As long as you're someone's vassal, you can try to overthrow him and take the title for yourself. Upon victory you'll gain the title and some prestige, and if the ruler you overthrew was a king or emperor, crown authority will go down one step. In addition, if your liege held any other titles, he'll be forced to abdicate them to his heir. If you stalemate you'll lose 100 prestige, and if you lose you'll lose 200 prestige and be imprisoned. Like with changing law, you cannot use this CB more than one step up the chain.

Dispute Succession CB
If you're a pretender to your liege's throne, or someone in your realm is a pretender to any throne, you can dispute the succession. Upon victory you (or the person you disputed the succession for) will gain the throne, and if it was a kingdom or empire crown authority will be reduced by one. White peace is impossible. If you lose, you'll be imprisoned, lose 200 prestige, and lose the claim.

Invasion CB
If you have a claim upon a throne or you're smaller than the realm in question (that is, you have fewer holdings in your realm), and the Pope condones your invasion (costing you 500 piety), you can use the invasion CB. Upon victory you'll get the throne in question, 400 prestige, and every occupied holding. As such, you should occupy every holding before enforcing demands, as then you can install your own nobles. If you stalemate you'll lose 100 prestige. If you lose you'll lose 200 prestige, and have to pay concessions, and you'll lose your claim upon the throne.

Tribal Invasion CB
You'll never get to use this CB unless you mod the game. It essentially just lets tribes like the Golden Horde and the Timurids attack anyone they neighbor, and take their lands. It works the same as the invasion CB for the most part. Any outcome incurs a mere 1-year truce.

Crusade CB
If the Pope has called a crusade, you can declare war upon the target. Upon victory you will gain all holdings (as long as they're occupied by you, or unoccupied) in the targeted duchy and 100 piety. If you stalemate you'll lose 50 piety and 100 prestige, and if you lose you'll lose 150 piety and 200 prestige.

Religious War CB
If you're in a different religious group than your target, your target is heretic, or you are heretic, you can declare a religious war. Upon victory you'll gain 50 prestige and all holdings (as long as they're occupied by you, or unoccupied) in the targeted duchy. If you stalemate you'll lose 50 piety and 100 prestige, and if you lose you'll lose 150 piety, 200 prestige, and be forced to pay concessions.

Religious Assistance CB
If another realm in your religion is being targeted by a Religious War CB, you can declare war upon the aggressor. The point of this is merely to prevent your own religion from shrinking. Winning the war will give you 50 piety and prestige, stalemating will lose you 50 piety and 100 prestige, and losing will losing will lose you 150 piety, 200 prestige, and you'll be forced to pay concessions.

Excommunicated Ruler CB
If someone has the same head of religion as you, and has been excommunicated, you can declare war upon them. Victory will give you 10 to 70 piety and 50 to 400 prestige depending on the excommunicated ruler's rank, and the target will be re-communicated and forced to abdicate. A white peace will lose you 50 piety and 100 prestige. Losing will lose you 100 piety, 200 prestige, and you'll be forced to pay concessions.

Gaining CBs
While some of these CBs you'll have merely due to your position, like the independence CB and the law change CBs, many of these can be gained on purpose.
First, the easiest type of CB to gain are claims. There are four primary ways to gain claims:

• Fabricate the claim. This doesn't works for anything above the ducal level (skill of 15 needed to forge a ducal claim)
• Marry someone who has an inheritable claim. Your children will have the claim and you can then push it
• Marry someone in your dynasty to someone who has an inheritable claim. Their children will have the claim, and you'll be able to push it
• Invite someone with a claim to your court. You'll then be able to push it as long as they're male.

Second, de jure claims are also relatively easy to gain. If you can create a duchy that overlaps another realm's territory, this will gain you a de jure claim, and the same applies if you usurp it. In addition, after pushing a claim for a duchy, you'll often have de jure claims.
Third, dispute succession CBs can, like general claims, be gained by inviting someone with that CB to your realm.
Fourth, excommunication CBs are easy to get as long as the pope likes you, but these won't help you grow your realm. They're good for gaining some prestige, though.
Fifth, you can get religious war CBs on essentially the entire world if you convert to a Christian heresy. The easiest way to get heresy to appear so that you can convert is appointing an antipope, as this lowers the moral authority of the church. The lower the moral authority of the church, the more likely heresy is to spread. Then upon the first chance you get, you should change to whatever heresy arises. You'll now have CBs upon everyone except other realms following the same heresy.
So while the drawbacks of heresy are severe (-30 opinion with all non-heretics, and increased rebel risk), the advantages when it comes to expansion are huge.

Using Your CBs
Pushing your own claims and similar is rather straight forward. When pushing someone else's claim however you have to be careful, or they'll end up as an independent realm. They'll only be your vassal if they are already your vassal, they're in your dynasty, or the claim you pushed was for an area that is de jure part of your realm. If the title they took is at the same level as yours or above they'll be independent even if any of the above conditions apply, unless you have a liege above you where the conditions still apply.
The easiest way to ensure that they'll be part of your realm after pushing their claim is granting them a county in your realm first. The only way they can become independent then as a result of the claim pushed, is if the title they gain is at the same tier as yours, or higher.

Summary
Casus belli and claims are easy to gain as long as you know what you're doing. Following these tips you should be able to expand easily.

• All wars except tribal invasions incur 10 years of truce. This only affects the aggressor.
• Marry claimants with inheritable claims to gain more claims
• Marry your dynasty members to characters with inheritable claims
• Invite males with inheritable claims and grant them a county
• Invite pretenders and grant them a county
• Make the pope love you and you can farm prestige off of excommunication
• Go heretic and you'll have CBs on everyone
• Create or usurp duchies that overlap the territory of other realms
• If you're going to declare multiple wars in a short time-span, make sure you declare them all before raising any levies, as they'll prevent you from declaring war"
  

 

[Meneth]

Warfare; Diplomacy By Other Means
First posted here.

In the previous installment I described how to get Casus Belli. In this installment I'll be going into how to use them, that is, how to do well at warfare. The summary and tactics sections are in a comment below as I hit the character limit.

The Basics

In a battle, each side has up to three flanks. These flanks will generally fight separately against the same flank on the opponent's side. Each flank has a commander, and its own units. To have more than one flank you need multiple armies, though they can be merged into one. An army composed of the soldiers from a church, city, and castle in the same province will suffice, but a single mercenary band will not.

Combat is divided into three phases; Skirmish, Melee, and Pursue. All battles will start in the Skirmish phase. This is when archers and horse archers excel, and they'll be the only ones doing any major damage. After a few days, it will switch to the Melee phase, where melee oriented units like heavy infantry and pikemen excel. Do note that flanks don't necessarily have to be in the same phase as each other, and they'll usually enter Melee at slightly different times. When the morale of a flank reaches 25%, they will start retreating, and combat will switch to the Pursue phase. This is where light cavalry truly excels, but heavier cavalry does well as well. After 5 days, the flank will be removed from combat.
When a flank no longer has an equivalent flank to attack, it will help another flank instead. It will now also get a flanking bonus of 10%, meaning it does 10% more morale and troop damage. The enemy flank will now be under attack from two flanks, thus taking considerably more damage, and will thus usually be rapidly eliminated from combat.

Combat Statistics
Each unit type has base statistics. These statistics are further modified by certain technologies and buildings, but generally they'll be quite similar for both sides. The base stats are as follows, in x/y format meaning attack and defense:

Light Infantry

• 3 morale
• Skirmish 2/3
• Melee 3/3
• Pursue 3/3

Heavy Infantry

• 5 morale
• Skirmish 0.5/5
• Melee 6/4
• Pursue 2/2

Pikemen

• Morale 6
• Skirmish 0.2/5
• Melee 5/8
• Pursue 0.2/2

Light Cavalry

• 4 morale
• Skirmish 2/5
• Melee 3/3
• Pursue 10/8

Heavy Cavalry

• 10 morale
• Skirmish 1/8
• Melee 10/8
• Pursue 8/5

Archers

• 1 morale
• Skirmish 8/3
• Melee 1/2
• Pursue 2/3

Horse Archers

• 7 morale
• Skirmish 7/4
• Melee 3/4
• Pursue 7/7

Attack controls how much damage an unit does, while defense controls how much damage it takes. The higher the morale of an unit, the more damage is needed for it to retreat.
As you can see, only two units are any good at skirmish, archers and horse archers. This means that an army with many of these units has the advantage of damaging the enemy severely early in combat, which can at times make the difference between victory and defeat. Further, heavy infantry and cavalry excel at melee, which is generally the largest part of combat. They're also not very vulnerable to the skirmish phase, and as such they can often win you the battle. Light cavalry on the other hand are only good at pursuit, so are as such only useful if you've already won the battle and want to inflict further casualties.
For the most part you and your opponent will have similar unit compositions, so this generally won't come into play much. However, when hiring mercenaries you should pay attention to what units you're actually hiring, and try to avoid mercenaries that are high on light infantry and archers, instead going for heavy cavalry and infantry.
Further, commanders have a moderate effect on combat. Every point a commander has in the martial skill increases the damage of his flank by 2%. As such, you should before important battles ensure that your flanks are using your best commanders so as to maximize your enemies' losses and reduce your own.

Improving Your Army
There are five ways to improve your army:

• Construct army buildings, covered in further detail here
• Research technology, covered in further detail here
• Strike the right balance between levy law and vassal opinion, covered in further detail here
• Improve your commanders
• Make your vassals happy

As the rest is covered in other installments, I'll focus on the last two points.
The first, improving your commanders is relatively simple. First, you need at least Limited Crown Authority, as that enables you to assign commanders. Once you have that implemented, you can invite high-skill commanders to your realm, either via inviting them normally and giving them some land or a councilor position, or by marrying them into your realm. Then you just have to make sure that the best possible commanders are appointed before any major battle. This could improve the damage your army does by several percent, making it easier for you to win battles, and reducing your losses. It will also decrease how much attrition you take, and you'll also get someone great for the Marshal position. This tactic is seldom necessary for a large realm, as you'll then generally have good commanders available already, just make sure to assign them.
Second, you can make your vassals happy. As mentioned in the installment on levies, the higher your vassals' opinion of you, the more levies they'll provide. As such it can be a good idea to send out gifts and honorary titles before raising levies so as to maximize how many you can raise.

Tactics
There are certain tactics you can employ to improve how well you do in war. Many of these tactics are common sense, but I'll mention them anyway.
One tactic that is useful for reducing how annoyed your vassals get with you, is raising troops from a minimal number of direct vassals. If you only need the troops of a single vassal to fight a war, only raise those troops. This vassal will now be the only one getting annoyed at you, while the rest will continue to be happy. The other vassals' levies can then be raised later if ever needed. If you're rich enough to support it, you can also consider using only your own levies, as then no one will be getting annoyed with you.
Second, you can use the bait and switch tactic. You offer up a small, easily beatable target to the enemy so that he attacks, then immediately once combat has started, you send in your larger army from a province away, thus winning the battle easily. This means you won't have to spend half an eternity chasing the army down, instead being able to quickly destroy it in a single or a series of decisive battles.
Third, if it is obvious you'll lose to an incoming enemy due to either a lack of troops or a lack of morale, consider sacrificing a small number of men to let the rest escape. Let a few men remain while the rest go to another province where they can hopefully recover or merge with a larger army. Make sure you leave more than 1/25 of the enemy army, as anything less than this will be destroyed instantly, and as such will not slow the enemy's advance down.
Fourth, you could try to bait the enemy into a province where they'll take attrition. Using an army smaller than theirs you can continuously pull back, leaving them in a province where their units will slowly die. Only works against large armies.
Fifth, if you can target a part of an enemy's army while it is split up, do so. While you might not be able to defeat the entire enemy army at once, you're likely to be able to defeat half their army, and the rest is then easy to mop up.
Sixth, always go for the wargoal first if you have the opportunity. Occupying wargoal holdings will give 75% more warscore, and once you hold every wargoal holding you'll slowly get warscore. This can ensure a quicker victory, and as such less losses to combat, sieges, and attrition. On the other hand, never let the opponent take the entire wargoal if you are the one being attacked, for the same reasons. Do note that the moment one side reaches 100% warscore, it can force victory.
Seventh, you should almost never split your army up into pieces smaller than the total size of the enemy army. If you do you risk losing a large part of your army, and being reduced to a position where you can no longer fight back. If you have a really good reason to do so, go ahead, but make sure you keep the rest of your army close.
Eight, if you're a coastal nation, utilize the mobility ships give you. You can transport units much faster by ship than on land, which can enable you to quickly strike at isolated enemy armies, then retreat back to sea. Make sure you don't put more than 8000 soldiers in a single sea province, or you'll suffer attrition.

Summary
By outmaneuvering or overpowering the enemy you'll be able to win most battles, and eventually the war itself. Overall my tips are these:

• Construct buildings to increase the size of your army. More detail here
• Research relevant tech, it can give you the edge you need. More detail here
• Appoint good commanders. Gain good commanders through marriage and invites
• When hiring mercenaries, go for heavy infantry and cavalry
• Keep your vassals happy
• Strike the right balance between levy law and opinion. More detail here
• Don't raise more troops than you need
• Ambush the enemy if possible
• Slow down the enemy's advance by sacrificing units if needed
• Go for the wargoals first
• Reach 100% warscore ASAP
• Divide and conquer
• Utilize the mobility ships give you

 

[Meneth]

Religion; Keeping the Church Strong
First posted here.

Religion is core to how Crusader Kings II works. As you can only play as christian characters (unless you bypass that limitation, some info on that later), this installment will be from a christian perspective. I'll be going into things like religious spread and heresy.
As always, there's a summary at the end.

The Basics
In Crusader Kings II, every province and character follows a sect, and this can have a major effect on their interactions with other characters. If a province is of a different sect than its liege its revolt risk will increase by 8%; far larger than the 2% penalty from being in the wrong culture group.
From a specific character's perspective, anyone of a different religious group is an infidel, while anyone of a different religion within the same religious sub-group (E.G., catholic Christianity) is a heretic. Infidels get a mutual -30 opinion modifier, heretics a -35 opinion modifier, and people of different sub-groups of the same religion (E.G., catholic and orthodox) get a -10 opinion modifier.
This penalty is reduced by the religious flexibility technology; 10% per level. As mentioned in the installment on technology, this only has an effect if the tech level has been achieved in the capital county of the character. Do note that their modifier depends on the tech-level in their capital, not yours, so increasing religious flexibility in your capital will not directly make your heretic/infidel subjects like you more, but it will likely make the tech spread faster to them.

Spread of Heresy - County Level
Religions from different religious groups will only spread via inquisitions. As such, if you want a province converted to the One True Faith you and/or your vassals will need to use your Court Chaplains to actively convert the province. Heresy on the other hand can spread on its own. The rate of spread is primarily affected by the moral authority (MA) of the church, and I'll describe how that, and any other factors, affects it. MTTH means "mean time to happen" on a per province basis. The lower the number, the more often it will happen.
Heresy appearing isolated:

• MA between 0 and 20% - MTTH = 5400 months (450 years)
• MA between 20 and 40% - MTTH = 7200 months (600 years)
• MA between 40 and 60% - MTTH = 9600 months (800 years)
• MA between 60 and 80% - MTTH = 19200 months (1600 years)
• MA between 80 and 100% - MTTH = 38400 months (3200 years)

As you can see, the moral authority can make a huge difference. Heresy will appear out of nowhere at a rate slighly above 7 times higher at a moral authority of 0-20 than at 80-100. At a moral authority of 0 to 20%, almost half of your provinces will statistically go heretic over the course of a campaign as the length of the campaign is only slightly below the MTTH (387 years as compared to 450).
However, heresy can also spread from province to province, and this happens at a much higher rate:

• MA between 0 and 20% - MTTH = 675 months (56.25 years)
• MA between 20 and 40% - MTTH = 900 months (75 years)
• MA between 40 and 60% - MTTH = 1200 months (100 years)
• MA between 60 and 80% - MTTH = 2400 months (200 years)
• MA between 80 and 100% - MTTH = 4800 months (400 years)

As you can see, even at its slowest this spread is faster than heresy appearing out of nowhere at its fastest. Further, the MTTH is multiplied by 0.75 if the county borders two or more heretic counties, giving these numbers:

• MA between 0 and 20% - MTTH = 506.25 months (42.1875 years)
• MA between 20 and 40% - MTTH = 675 months (56.25 years)
• MA between 40 and 60% - MTTH = 900 months (75 years)
• MA between 60 and 80% - MTTH = 1800 months (150 years)
• MA between 80 and 100% - MTTH = 3600 months (300 years)

Spread of Heresy - Character Level
Heresy can also spread from counties to characters, and from character to character. Only courtiers can pick up heresies from provinces, but they can then spread it onto other characters. The factors affecting province to character spread are these:

• Cynical and MA between 0 and 20% - MTTH = 50.625 months (4.21875 years)
• Cynical and MA between 20 and 40% - MTTH = 67.5 months (5.625 years)
• Cynical and MA between 40 and 60% - MTTH = 90 months (7.5 years)
• Cynical and MA between 60 and 80% - MTTH = 180 months (15 years)
• Cynical and MA between 80 and 100% - MTTH = 360 months (30 years)
• MA between 0 and 20% - MTTH = 202.5 months (16.875 years)
• MA between 20 and 40% - MTTH = 270 months (22.5 years)
• MA between 40 and 60% - MTTH = 360 months (30 years)
• MA between 60 and 80% - MTTH = 720 months (60 years)
• MA between 80 and 100% - MTTH = 1440 months (120 years)
• Zealous and MA between 0 and 20% - MTTH = 1012.5 months (84.375 years)
• Zealous and MA between 20 and 40% - MTTH = 1350 months (112.5 years)
• Zealous and MA between 40 and 60% - MTTH = 1800 months (150 years)
• Zealous and MA between 60 and 80% - MTTH = 3600 months (300 years)
• Zealous and MA between 80 and 100% - MTTH = 7200 months (600 years)

As you can see, both traits and moral authority can make a huge difference here, with a range from 50 months to 7200.
Further we've got, as mentioned earlier, character to character spread. Character to character spread can happen as long as the heretic is capable, 16+, and not a prisoner, and is in the same court as at least one other person that is capable, free, 16+, same religious group, has an opinion of 25+ of the heretic, and is not a heretic. Four traits (that the heretic may have) affect the chance of this happening, as well as the moral authority of the church. When this event triggers it will select a random character that fulfills all the earlier criteria, and fire an event for him/her asking him/her to convert to the heresy.
As the total possibilities are so many, I'll list what the MTTH rather than the entire list:

• Base MTTH of 120 months
• Cynical multiplies it by 10
• Zealous divides it by 4
• Diligent divides it by 2
• Slothful multiplies it by 3
• MA between 0 and 20% multiplies it by 0.5625
• MA between 20 and 40% multiplies it by 0.75
• MA between 60 and 80% multiplies it by 2
• MA between 80 and 100% multiplies it by 4

As such, we get a range from 8.4375 months (zealous, diligent, and MA below 20%) to 14400 months (cynical, slothful, and MA over 80%)
Now, this will not automatically make the target heretic. Instead, the target will have several choices; embracing the heresy, demanding the heretic converts back (can only be done if (s)he is the heretic's liege, and has a Diplomacy stat of 6+), imprisoning the heretic (has to be the heretic's liege, not a close relative, and have the zealous, wroth, or lunatic trait), or simply saying no.
Without any modifiers, all of these choices are equally likely, but two factors modify the chance of embracing the heresy; being independent halves it, and being a king or emperor quarters it.
As such, the ruler of an independent realm is unlikely to convert to a heresy, but it can happen.
Do note that while infidel religions cannot spread to your courtiers this way, they can be spread by infidel vassals using their court chaplains. As such, you should avoid having infidel vassals (and with medium crown authority you can revoke their titles for free anyway)

Converting Provinces
Converting provinces is relatively simple, you just put your court chaplain in the province with the inquisition mission. Your vassals might do this as well. The chance of this happening is modified by several factors, both in the county and on the court chaplain's part:

• Base MTTH of 960 months
• Same culture group multiplies it by 0.75
• Same culture multiplies it by 0.75
• Same religious group multiplies it by 0.5
• Heresy multiplies it by 1.5
• Court Chaplain learning skill of 1 multiplies it by 2.44
• Skill of 2 multiplies it by 1.953
• Skill of 3 multiplies it by 1.5625
• Skill of 4 multiplies it by 1.25
• Skill of 10 multiplies it by 0.75
• Skill of 11 multiplies it by 0.5625
• Skill of 12 multiplies it by 0.42
• Skill of 13 multiplies it by 0.32
• MA between 0 and 20 multiplies it by 8
• MA between 20 and 40 multiplies it by 2
• MA between 60 and 80 multiplies it by 0.75
• MA between 80 and 100 multiplies it by 0.5625

As such, assuming you've got a descent court chaplain (skill 13 or higher) the MTTH ranges from 48 to 2430 months. MA can change the MTTH by a factor slightly above 14.

Popes
The pope has several powers. The first, and strongest, is crusades. The pope can call a crusade as long as the moral authority of the catholic church is 5% or higher. This calls for a religious war, generally against muslims, but after 1198 crusades can also be called upon pagans. The goal of a crusade is either to take an area considered holy by the catholic church, or to take back land taken from christians by another religious group.
Second, but also importantly, the pope has the power to excommunicate catholic rulers as long as the moral authority of the church is above 20%. This will make the ruler's subjects get a major opinion penalty of -30 towards the ruler, and will give everyone the excommunicated ruler casus belli against the ruler. This costs the person who asked for excommunication 100 piety.
Third, the pope can condone invasions. More detail on this in the installment on casus belli. This can be done as long as the MA of the church is above 30%
Fourth, the pope can conduct divorces. Short of one part of the couple dying, this is the only way to end a marriage. This costs the person who asked for the divorce 100 piety, and will make the spouse's family unhappy.
Fifth, all church taxes are paid to the pope unless the bishop prefers his liege or an antipope. This can be a huge amount of money per year, and as such the Papacy is usually one of the richest realms in the game.

Antipopes
On the other hand, there are also antipopes. Antipopes are bishops who directly challenge the popes authority, and thet are a constant drain on the moral authority of the church. An antipope has two of the powers that popes have; excommunication and taxation.
The character who controls an antipope will be able to request excommunication of anyone in his realm, and he and all his vassals will be protected from excommunication by the real pope. This can be a major asset if the current pope doesn't like you, and you have political enemies with high enough piety, and good enough graces with the pope, to get you excommunicated.
Second, an antipope also has the potential to bring in huge amounts of taxes. Every catholic bishop who prefers the antipope over the real pope will pay taxes to him instead, and every bishop in the realm of the antipope controller will get the head of religion opinion bonus of 10 towards the antipope rather than the real pope.
The antipope will also have a claim upon the papacy, and by pushing this claim and winning the war, he will be installed as head of the catholic church, and the old pope will become an antipope with no successor. The split in the church will be gone upon the death of the ex-pope. The only real benefit to this is the +100 opinion modifier you'll get with the new pope, which will disappear upon succession.
While an antipope has the major benefits of tax and protection from excommunication, it will be a gradual drain on the church's moral authority. Each antipope in existence will decrease the MA of the church by 0.1% per year, which will over time reduce the rate of spread of Catholicism while increasing the spread of heresy. Due to this major disadvantage I would not recommend holding onto an antipope for any major period of time unless you deliberately want to become a heretic.

Tactics
You should use your court chaplain to spread your religion at all times, as then you'll end up with much fewer rebellions once you lose the 8% revolt risk from 'wrong religion'. This will also increase the MA of the church slightly every time a province converts, and the pope's opinion of you.
Second, you should make sure your court chaplain has a skill of at least 13, or conversion will be slow.
Third, concentrate on heretics before infidels, as your vassals will never convert to an infidel religion, but can convert to a heresy. The heresy penalty is also larger than the infidel penalty.
Fourth, when converting provinces you should concentrate on those of your own culture and/or cultural group first, as these will convert faster.
Fifth, completing crusades is a great way to increase moral authority, as well as gain the Crusader trait (makes all your bishops and the pope love you, and is gained the moment you set foot in the crusade target area), plus gain a few provinces. A 20% increase in moral authority can make a large difference when it comes to the spread of heresy and the One True Faith.
Sixth, if you want to go heretic at some point, appoint an antipope as early as possible. The lower the moral authority of the church, the faster heresy will spread, and the easier a time you'll have converting yourself and your vassals to the heresy.
Seventh, beware of having an antipope for any extended period of time, with the exception of the scenario above. While you'll rake in money for quite a while, as the MA of the church goes down, heresy will become rife, and your vassals will start hating you and the church taxes will dry up as less and less bishops follow your religion.
Eight, don't keep counties of another religion for yourself, give them to a vassal instead. They'll have a court chaplain of their own that can convert their counties, thus speeding up the spread of your religion. Creating and giving out duchies also has the benefit of creating yet another court chaplain. However, you should try to keep your vassal holdings as small as possible, to maximize the number of court chaplains in existence.

Differences Between Orthodox and Catholic
Do note that the orthodox church has no antipopes, cannot call crusades, and all church taxes go to the bishop's liege. Free/papal investiture also does not apply to orthodox factions, you cannot control who takes over when a bishop dies.
This means you don't have to keep your bishops happy for their taxes to go to you, and also that antipopes will never hurt the church's moral authority. However, it also means you'll never gain the benefits of crusades.

Summary
Keep the church strong and you'll reap the benefits of rapid spread of your religion, and hampered heresy. Weaken the church and heresy will be rife, and your religion will be hard to spread. My tips are as follows:

• Antipopes will hurt you in the long run
• Go crusading if you can win
• Prioritize fighting heresy over infidels
• Appoint a good court chaplain
• Create and give out duchies in regions of a different religion
• Balkanize your vassals
• Focus on counties of your own culture first
• If there are any counties in your realm of a different religion, try to convert them
• Avoid having infidel vassals, they might convert your courtiers

 

[Meneth]

Culture; Unity Through Homogeneity
First posted here.

As culture in Crusader Kings II is in many ways similar to religion, it seems a fitting topic to follow up the installment on religion. Unlike religion, culture has only a minor effect upon the peasantry, most of the effect is instead on your vassals. I'll go into what culture does and how you can use it to your advantage.
As always, there's a summary at the end.

The Basics
Culture is an abstract representation of the ethnicity and traditions of the peasantry, and whom nobles identify with. In Crusader Kings II all cultures are created equal, there are no advantages inherit to any one culture beyond superficial things like names and portraits with the exception of a limited number of events that depend upon or are influenced by culture.
Every culture belongs to a culture group, and is as such closer to other cultures in the same groups than cultures outside it. Culture mismatch can hurt both on the provincial level and inter-character relations.

The Provincial Level
Every county in the game has a culture representing the major culture there. At game start most realms will be relatively homogenous, with few realms containing more than culture, and even fewer containing more than one culture group.
However as a realm expands it will inevitably encounter other cultures and culture groups, which will give various penalties, both permanent and temporary.
The permanent penalty (unless culture changes) is a 1% revolt risk for being a different culture than the liege, and 2% if it in a different group. In addition upon conquering a region it will get a temporary penalty if it is a different culture. If it is in the same culture group it will get the following penalties, which are all doubled if it is of a different culture group:

• Lasts 10 years
• -50% levies
• -25% levy reinforcement rate
• -25% income

As you can see, this means that a newly conquered area will take quite a while before it is of any real value, and even after the temporary penalties disappear you'll still have to deal with the revolt risk, which also reduces tax by 1% per 1% revolt risk.
Also, as mentioned in the installment on religion, a county being of its liege's culture makes it considerably easier to convert the province.

The Character Level
However as mentioned earlier, culture is not limited to counties alone. Every character in the game identifies with a culture, and this affects their relations with other characters in the same realm.
Being of a different culture will reduce vassals' opinion of you by 10, and by 20 if you're of a different culture group. This penalty is modified by the cultural flexibility in the character's capital county.
Second, being of the same culture reduces character revolt risk directly by 15%. Combined with the lack of an opinion penalty makes same culture vassals much more loyal, and homogenous realms much more stable than others.

Spread of Culture - Character Level
Every character will be born with the culture of his father in a patrilineal marriage, or his mother in a matrilineal marriage. With very few exceptions, the only way to change this is via the child's guardian. If the guardian of a child is of a different culture there's a decent chance the child will change to the guardian's culture. The mean times to happen are as follows:

• Diligent and gregarious guardian - 30 months
• Diligent or gregarious guardian - 60 months
• No relevant traits guardian - 120 months
• Diligent + shy or gregarious + slothful guardian - 120 months
• Shy or slothful guardian - 240 months
• Shy and slothful guardian - 480 months

As you can see, a culture change happens about 50% of the time if the guardian has no traits modifying the chance, as a child generally has a guardian for 10 years. If the guardian is diligent and/or gregarious it becomes far more likely, as the normal distribution is then centered at 2.5 or 5 years, while on the other hand if the guardian is shy and/or slothful it becomes quite unlikely.
So if you want to change the culture of your child, you should assign a guardian of the desired culture that has the diligent and/or gregarious trait.

Spread of Culture - Provincial Level
Every county has a culture from the start of the campaign, but this can be changed over time. The event for a province changing culture works like this:
The event is called on a character-basis, not a county basis. Thus, the chance is not per county, but per character. For the event to trigger, the character has to have a county in his demesne not of his culture, and it must border at least one other province of the character's culture that is owned by a character (which could be the very same character) of the ruler's culture. Thus it is near impossible to spread any culture to islands, as they cannot possibly border a county of your culture unless it was present at game start. While there is an event that lets culture spread to culturally unconnected provinces, this event can only ever fire if the province is of a different religion, and as a province changes religion much faster than culture, this event will almost never fire. The British isles for example are thus for all practical purposes limited to (in the default campaign start)) Saxon, English, Welsh, Scottish, Irish, and Norwegian, while most other islands have only a single potential culture.
Now, the event itself depends primarily upon a single factor: the ruler's stewardship, and the mean time to happen is as follows:

• 0-1 stewardship - 6075 months (506.25 years)
• 2 - 4050 months (337.5 years)
• 3 - 2700 (225 years)
• 4 - 1800 (150 years)
• 5-9 - 1200 (100 years)
• 10 - 900 (75 years)
• 11 - 675 (56.25 years)
• 12 - 506.25 (42.1875 years)
• 13+ - 380 (31.67 years)

It is also halved if you're mongol and it is before the year 1300, but that is a rather unlikely scenario.
As you can see, as long as a character has high stewardship he can convert counties to his culture rather quickly.

Tactics
First, as I said in the section on changing character culture via guardian: if you want to change your child's culture, assign him a guardian of that culture with the diligent and/or the gregarious trait. He'll be very likely to change culture. Conversely, if you want to keep your culture pure, be careful who you assign as his guardian.
Second, assign high-stewardship characters of your culture as counts on the edge of your culture. They'll rapidly change the culture to their own, getting rid of the revolt risk.
Third, try to have a single county per character. As the culture change event fires on a character level, a single character owning more than one county makes it less likely to happen on a per-county level.
Fourth, try to keep your vassals of your culture, as you'll get lower revolt risk and avoid the foreigner opinion penalty.
Finally, prioritize conquering same-culture provinces over provinces of a different culture. Prioritize same culture-group over different culture groups. You'll get less severe penalties that way.

Summary
By keeping your realm culturally homogenous you'll have an easier time controlling it. My tips are as follows:

• If you want to culture-change, appoint a Diligent/Gregarious guardian of a different culture
• Assign high-stewardship characters of your culture as counts in different culture provinces bordering your provinces
• Try to keep a single county per character
• Try to keep your vassals of your culture
• When conquering, prioritize same culture, over same culture group, over different culture group

 

[Meneth]

Holding Types
First posted here.

Every county in Crusader Kings II has at least one holding. Holdings produce all levies and taxes, and are thus important, yet easily ignored. I'll be going into how the different types of holdings work, and how you can use them to your advantage.
As always, there's a summary at the end.

The Basics
Every county has at least one holding, and most have three. These holdings provide both income and taxes, and every holding is held by a character. There are three types of holdings:

• Baronies: Focus on troops
• Cities: Focus on tax
• Bishoprics: A middle ground between baronies and cities

Each of these three types have an associated character type; baronies are typically owned by nobles, cities by burghers, and bishoprics by clergy. Typically a barony will be the capital of a province, but there are some exceptions, and it is possible to switch the capital simply by granting the county to a someone of a different character type. The capital of a county is indicated in the top-right of the county overview, and whoever owns the capital owns the county.

Holding Owners
In general, only clergy hold churches, burghers cities, and nobles baronies. However, it is possible to assign someone not of this type to a holding. If they have a holding on a higher tier however, they will almost always give the holding to a vassal instead. The reason for this is the large penalty associated with owning a holding of the wrong type; you lose out on 75% of the income of the holding. This means that tax-wise it cannot pay off to hold a holding of the wrong type rather than one of the right type. In fact with the exception of baronies, giving the holding to a vassal instead will get you higher taxunless you've got high stewardship.
On the other hand, you get the full levies of a holding if you own it rather than a vassal. You would still benefit more from holding a barony than any other type of holding, as they give the most troops, and will give you the most tax due to the wrong holding penalty.

Vassal-Liege Relationship
Typically all holdings in a county will be held by vassals of the count, with the count vassalized to a duke or king. However, it is entirely possible for a county to be owned by someone who is not a noble. This can benefit the ruler's liege considerably, as he'll be able to charge different tax rates than he would with a noble. While noble taxes default to 0%, city taxes default to 25% and church taxes to 35%. Even at 10 or 20% noble tax, you'll be getting more from having a burgher or bishop as the ruler of a county.
However, doing so is not entirely without penalties. Any ruler at count level or above will get -30 opinion with his liege if his liege is not the same character type. So if you as a noble have a bishop ruling one of your counties, you'll get -30 opinion with him which could impact both tax and levies.
Second, bishops (if you're catholic) will only pay you any tax if they like you more than they like the pope. If they like the pope more than you, you'll lose out on tax entirely.
You can also appoint burghers or bishops as dukes, once again giving great tax benefits. However, they'll be getting -30 opinion with every vassal they have unless the vassals are the same character type, which is likely to reduce the tax trickling up to you. Even taking this into account however, you'll still probably get more tax from a bishop or burgher than you would from a noble. However, due to the -30 opinion, you'll end up getting less levies from that bishop/burgher's demesne.
Another major drawback is that bishop and burgher succession is generally much less predictable than noble succession. If you've got free investiture you can of course appoint every bishop, and thus control the succession entirely. However, if you've got papal investiture you have no control whatsoever over who rules the county/duchy after the first ruler dies. With cities you've got similar problems as cities are generally Open Elective, meaning anyone in the burgher's court can succeed.
Thus unless you are orthodox or heretic, you'll risk losing out on taxes with bishops, while with burghers you cannot control the succession. You also as mentioned have to deal with some pretty big opinion penalties.
Do note that granting titles to bishops has the added benefit of giving you piety. You get 25 piety from granting a holding, 100 for a county, 200 for a duchy, 800 for a kingdom, and 6400 for an empire. Thus giving a few counties to bishops can be a great way to get piety which makes getting the Invasion CB pretty easy.

Summary
By appointing a burgher or bishop as the ruler of a county or duchy, you could reap major tax rewards. However, you'd likely end up with fewer levies, a higher risk of rebellion, and reduced control over succession.
If you think these drawbacks are worth it, I'd recommend experimenting with this tactic and seeing if you like it.
My summarized tips are as follows:

• Don't hold onto cities or bishoprics if you've got baronies you can fill your demesne with instead
• If you appoint a burgher or bishop as ruler of a county or duchy, you'll generally get much more tax from them
• Burgher/bishop counts and dukes will generally give less levies
• Burgher/bishop counts and dukes are more likely to rebel
• Burgher/bishop counts and dukes are more likely to get deposed by their vassals
• Bishop counts and dukes could end up paying all their taxes to the Pope rather than you
• If you don't have Free Investiture you cannot control bishop succession at all
• Burgher succession is extremely unpredictable
• If you need piety, grant titles to bishops

 

[Meneth]

Crown Authority
First posted here.

There are two types of crown law: Crown authority, and for Catholics, investiture. These two laws together have a large effect upon your realm and I'll go into what they do, what advantages they bring, and what disadvantages they bring.
As always, there's a summary at the end.

The Basics
The two crown laws decide what authority the king or emperor of a realm has. Crown authority represents the centralization of powers to the monarch, while investiture decides who controls who becomes bishops; the Pope or the King.
Crown laws only apply within the de jure realm they're set to. Thus if you conquer territory in another de jure kingdom, their crown laws will apply to those holdings. The aspects of crown law that apply specifically to vassals will be based on where the vassals have their capital. It is entirely possible for a vassal to be getting the opinion modifier for high crown authority for example, while most of his holdings are in a kingdom with lower crown authority.
Crown laws can be put up for vote at any time as long as you don't have a regent, you're not in a civil war, and you haven't changed a crown law with that character.

Investiture
Investiture laws is a small set of laws that only apply to Catholics; no other religions will have it. Investiture law decides if the Pope appoints bishops, or if their liege does. This means that if you have Papal Investiture you will be unable to affect who your bishops are.
If you've got Free Investiture you'll be able to appoint the successor to any bishopric that is your direct vassal, and every subject within your de jure kingdom will be able to do the same. This makes vassal bishops considerably happier with their lieges, as they are grateful for having been appointment, and they therefore get +25 opinion with whoever their liege is. Any vassal you have that himself has bishops as vassals will also be happy with you, as he now has control over his bishops. You'll thus get +10 opinion with most of your vassals.

However, the Pope will be quite unhappy with this state of affairs. You will get -30 opinion with the Pope making you much more vulnerable to excommunication. In addition, every time a new king gets the throne the Pope will request, generally within a few years, that the investiture laws are changed to Papal Investiture, which will give you the option to comply (which will raise the moral authority of the Church by 2%), refuse (reduces MA by 2%), bribe the Pope (costs 200 gold), or if you have a Learning skill of 16+, refuse on theological grounds (gives you 1 piety).

This means that over time, Free Investiture does have the potential to be a moderate money drain over time. However, as long as your realm is moderately large, the gold needed for a single Papal bribe is unlikely to be more than a couple year's income at most. The largest disadvantage to Free Investiture is the much increased risk of excommunication, and as long as you have political enemies and a lack of traits the Church likes, you can easily end up excommunicated, giving every Catholic in the world a casus belli against you, and reducing all your vassals' opinion of you by 30.
However, Free Investiture is still generally preferable over Papal Investiture due to the boosts to vassal opinion. 10 opinion with your nobles can at times make the difference between rebellion and loyalty, and the 25 opinion with bishops makes their taxes much more likely to go to you than the Pope.

Crown Authority
Crown Authority decides how much power the king has, and affects several aspects of your realm.
The first, and one of the most important, aspect crown authority decides is how many levies your vassals are obligated to provide. This starts at 0% at Autonomous Vassals, and increases by 10% per level, to a max of 40% at Absolute Crown Authority. This overrides both Opinion and Levy Law as long as it is higher. Higher crown authority thus means that you're able to call on larger levies in times where your vassals dislike you, for example right after succession.
Further, each step of crown authority gives the king privileges.

At Limited Crown Authority the king gets the ability to revoke titles and the ability to appoint generals. This level of crown authority is extremely important, as this will let you strip a single title from any vassal that rebels, thus allowing you to redistribute power in a way that makes the realm more stable. Second, you will no longer risk being stuck with horrible commanders in an army stack, as you'll be able to appoint someone more suited to the role. At times, this can win you fights, and potentially wars.

At Medium Crown Authority the crown gets another two important privileges; free revocation of titles from infidels, and no fighting between vassals. By being able to revoke titles from infidels and heretics you'll no longer have to deal with vassals having large Infidel/Heretic penalties, and you'll be able to redistribute their titles as you see fit. No infighting between vassals means that vassals will no longer be able to go to war against each other except when rebelling against their liege, thus you'll almost always have their levies available when you need them. It will also prevent vassals from getting powerful via intra-realm warfare.

Upon passing High Crown Authority titles can no longer be inherited by anyone outside the realm, so you will no longer lose parts of your realm due to inheritance. Foreign nobles will no longer be able to snag your lands from right under your nose, and inheritance gets more predictable.

Absolute Crown Authority gives one final privilege: vassals can no longer go to war (except to rebel) at all. This means that your vassals will no longer be able to grow powerful by taking land from outside the realm, and makes them thus more manageable. The drawback is of course that you now cannot grow that way either; you will personally have to start all conquests.

Increasing crown authority will however not only give privileges, it also brings some pretty severe penalties. First and foremost are the opinion penalties. At Autonomous Vassals you'll get +5 opinion with all your noble vassals, but this rapidly goes down. At Limited, you get -5 opinion; at Medium you get -10; at High you get -20; at Absolute you get -30. This makes vassals less willing to provide tax and levies, and more likely to rebel.

Upping crown authority also increases risk of rebellion directly. At Autonomous Vassals all vassals will have a -20% chance of rebelling, but this increases by 10% each level, ending at +20% at Absolute Crown Authority. Beyond this and the opinion penalty however, there are very few drawbacks. In total you get -35 opinion from going to max authority, and +40% rebellion risk (+17.5 to 35 from the opinion hit, for a total of 57.5 to 75%).

Due to how severe the rebellion and opinion penalties are, I would not recommend going beyond Medium Crown Authority. At this point you've got the most important privileges without incurring too large penalties. Unless you often lose land to inheritance there is no real point to going to High Crown Authority as it is seldom worth the opinion and rebellion hit.
Do also note that for 5 years every vassal will get -30 opinion with you if you increase crown authority.
Crown authority is also needed to set some of the succession laws. You need Medium authority for Seniority, and High for Primogeniture. You can lower the crown authority afterwards without losing the succession law.

Summary
Investiture law decides if you or the Pope appoints bishops. Free Investiture makes your vassals happy, and Papal Investiture makes the Pope happy.
Crown Authority decides how much power the king has, but incurs major opinion and rebellion penalties.
My tips are as follows:

• Unless you often get excommunicated, use Free Investiture
• Medium Crown Authority generally gives the best of both worlds
• Go to High Crown Authority if you're often losing land to inheritance
• If you want to switch to Seniority succession, you'll need Medium Crown Authority
• If you want to switch to Primogeniture succession, you'll need High Crown Authority
• Limited Crown Authority is an absolute minimum; you need the ability to revoke titles

 

[Meneth]

Distribution of Power; Keeping Your Vassals Weak
First posted here.

If you've played Crusader Kings II for any decent length of time, you've almost certainly encountered what happens when vassals get too strong and dislike you.
If any single vassal gets strong enough to challenge your power, you're at constant risk of rebellion. Everything you've worked for could be undone in years. Thus I'll be going into how to prevent this from happening, concentrating on keeping your vassals weak.
As always, there's a summary at the end.

The Basic Concept
To prevent sizable rebellions, you have one primary goal: Prevent your vassals from having more power than you. This is achieved in multiple ways.
First, you have to keep yourself strong.
Second, you don't want your vassals to hold a lot of titles.
Third, you don't want your vassals to have a lot of vassals.
Fourth, you want to keep your vassals happy.

Keeping Yourself Strong
Keeping yourself strong in the long term primarily relies on two factors: Number and concentration of holdings, and construction.
You want to hold every singe county in two duchies you own that are either bordering each other, or very close to each other. These two duchies should together have 7 to 10 counties so that you can use most of your demesne limit without having to construct holdings.
By keeping your entire demesne in two duchies you avoid the penalty from having more than two duchies, and you avoid the penalties for vassals desiring your duchies. No vassals will thus be able to plot for your duchies, thus keeping your powerbase secure.
The advantage of keeping your demesne limited to a small geographical area is that you can now gather up your army very quickly, so you'll be able to respond quickly to any rebellion with very low risk of your units being picked off separately.
Second, you want to upgrade your holdings as much as possible. This is covered in further detail in the installment on construction.
By upgrading your holdings you'll have more money available, and more troops. You'll also refill your levies faster, so you'll be able to recover from wars faster.
As your vassals will seldom be able to upgrade their holdings to the same extent as you, construction can give you a large advantage.

Keeping Your Vassals Weak
The other side of the coin is keeping your vassals weak, and reducing their powerbase when possible. If you expand via conquest, you'll often have titles that you need to give out. You should be quite careful about who you give these titles to, as it is easy to end up with a single vassal holding many titles, and eventually being able to challenge your power.
The strategy I recommend for giving out counties goes like this: Search for characters that are not rulers, are of your religion, are male, and are of your culture. You should then sort by dynasty, and scroll down to your own. You should now find someone who is not heir to anything, and who's heir does not own anything. You then give that person a single county with all its holdings (if applicable). The new count will then soon make the holdings in the county into vassals, and will be of no threat to you.
For duchies you do much the same. Search for characters that are rulers, are of your religion, and are of your culture. Sort by dynasty, and scroll down to your own. Find someone who owns a single county or barony. One county and one barony is also fine, but only a single holding is preferable. This person should get the duchy. It does not matter if (s)he actually holds any counties within the duchy; that is their problem, not yours. By following this strategy you'll end up with dukes who hold a single duchy and a single county, and will be unlikely to ever be able to challenge your power.

Whenever a vassal rebels and you beat him, you should strip him of his primary title. To do this you will need Limited Crown Authority. You can then follow the strategy described above to give this title to someone else.
Further, you can deliberately make strong vassals rebel so that you can imprison them and strip them of a title. Simply give them the court jester honorary title, and raise their vassals and just leave them there. Eventually they will rebel, and then you can crush them and take a title from them.
Another way to make them rebel without incurring tyranny is imprisoning them with a just cause. They'll rebel approximately half the time, and upon crushing their rebellion you'll be able to strip them of a title. If they don't rebel you can just ransom them, thus taking a bit of money from them and giving it to you, and you'll likely end up with another reason to imprison them later.
Beyond how you distribute county/duchy grants, and stripping of titles, it is very important to attain Medium Crown Authority.
Medium Crown Authority will prevent all intra-realm warfare with the exception of rebellion. This will make it near impossible for your vassals to expand via conquest, and they're thus much more likely to remain weak. They'll also not be using up huge amounts of levies on pointless internal wars, so you'll have the levies you need when you go to war.

Keeping Your Vassals Happy
Finally, you should do your best to keep your vassals happy. The two most important ways of doing this is keeping your vassals the same culture as you, and keeping them the same religion as you. This lets you avoid the large 'foreigner' penalties, and you get -15% risk of rebellion for each. Having all your vassals of the same religion is especially simple, as at Medium Crown Authority you can revoke any title held by a Heretic or Infidel without incurring tyranny.
For culture you should simply make sure to never give titles to people of a different culture unless you have a very good reason to, for example so as to push their claim on some other title. You can also like described above, deliberately make them rebel so that you can give their titles to someone else.
Further, you should groom your heir yourself. Unless you have good reason not to, your heir should always be your ward, not someone else's. This will let you make various choices throughout his childhood, thus having him end up with good traits. A few good traits can make a huge difference both when it comes to chance of rebellion, and the levies and taxes he can get from his vassals.
Finally, apply bribes and honorary titles strategically. Unless you actually want someone to rebel it is usually better to pay them off with a bribe than to have to crush their rebellion. Do note that honorary titles only expire upon the recipient's death (or rebellion); they'll even persist beyond the ruler's death. As such you should be careful about when you give them out, as there's a rather limited number of them.

Summary
Keep your vassals happy and weak, and yourself strong, and it becomes much easier to hold onto the throne.
My tips are as follows:

• When giving out a county, give it to a dynasty member who holds no other titles
• When giving out a duchy, give it to a dynasty member who holds a single county or barony
• After crushing a rebellion, strip every member of the rebellion of their primary title. You'll need Limited Crown Authority
• Revoke the titles of any infidels and heretics. You'll need Medium Crown Authority
• If any vassal is getting too strong, induce rebellion then strip him of a title
• Avoid having vassals of different cultures and religions. Inducing rebellion can help
• Get Medium Crown Authority, it will stop vassals from expanding via intra-realm conquest
• Hold every county in two bordering duchies
• Upgrade your holdings as much as possible
• Be your heir's guardian
• Give out bribes and honorary titles to prevent rebellion

 

[Meneth]

Councilors; Rulers Need Advisers
First posted here.

Your councilors in Crusader Kings II are quite important. Each councilor affects the well-being of your realm, and they all have different missions they can do. I'll be going into the effects of councilors, and how to use them to your advantage.
As always there's a summary at the end.

The Basics
There are five types of councilors, one for each attribute. Chancellors correspond to Diplomacy; Marshals to Martial; Stewards to Stewardship; Spymasters to Intrigue; Court Chaplains to Learning. Each councilor will add his statistic in the relevant attribute to yours and half of your spouse's to decide what your State Attribute in that area is.
State Attributes have some important effects. A full list of passive effects are below:

• State Diplomacy - Every second point increases other character's (unless they're in your court) opinion of you by 1. Each point will also increase monthly prestige gained by 0.01, and Cultural tech growth by 1%
• State Martial - Every point increases morale refill by 1 percentage point, soldiers' defense by 1% (making them take less damage), and Military tech growth by 1%
• State Stewardship - Every point increases the income from your demesne by 2%, starting at -10%, and Economical tech growth by 1%
• State Intrigue - Every point makes discovering plots more likely
• State Learning - Every point increases monthly piety gains by 0.02, and tech growth by 1%

As you can see, virtually every state attribute is useful. The higher your state attributes, the better your realm will be run. Diplomacy will make succession easier, Martial will make war easier, Stewardship will make you richer, Intrigue will protect you from plots, and Learning will give you technology (assisted by most other attributes)
Further, each councilor has missions he can do.

Chancellors
A chancellor is your diplomatic councilor, and his abilities is based on his Diplomacy attribute. He will make everyone like you more, except characters in your court (as they are only affected by personal Diplomacy), and he'll boost your prestige and cultural tech growth.
The chancellors has three missions he can go on: Improve Diplomatic Relations, Fabricate Claims, and Sow Dissent.

The first mission, Improve Diplomatic Relations, sends your chancellor to a county to improve relations with whoever rules in it with the exception of priests. This has a mean time to happen (MTTH) ranging from 293 to 38 months, and it depends entirely upon his Diplomacy skill and is at its minimum at 13+. Upon success a random ruler in the province will get +25 relations with you for two years. The mission has one failure state with a MTTH once again ranging from 293 to 38 months, but maxing out at skill 13. If triggered it will reduce a random ruler in the province's opinion of you by 20 for two years.
As the effects only lasts a mere two years, this is seldom worth doing.

The second mission, Fabricate Claim, sends your chancellor to a county to get you a claim on it or the duchy it is part of. This has a MTTH of 878 to 114 months, at its lowest at 13+ Diplomacy. If his skill is under 15, he will never be able to claim a duchy. If it is between 15 and 17, he has a 10% chance of claiming a duchy, from 18 to 19 a 20% chance, and at 20+ a 30% chance. Claiming a county will cost a certain amount of gold based on your income, and 50 to 150 prestige depending on your rank. Claiming a duchy will cost twice as much gold and prestige. This mission has one failure state with a MTTH ranging from 586 to 76 months, maxing out at skill 13. If this triggers an event will trigger for the noble you're trying to fabricate a claim upon. He will have the choice to assassinate your chancellor, bribing him, or ignoring it. If he decides to assassinate him there's a 50% chance it will succeed. If he is bribed and accepts, he will be unable to fabricate claims for a year. If you have no other way of gaining claims (more info here) this mission can be a good idea. Just ensure you've got a good amount of gold lying around. You'll get 10 Piety if you let a county claim go, and 20 if you let a duchy claim go.

The chancellor's final mission is Sow Dissent. This will send your chancellor to a county with the intention to disrupt the relationship between any ruler in it and his liege. This mission only works outside your realm.
The MTTH ranges from 293 to 38 months, and is lowest at 13+ Diplomacy. It will lower one ruler in the province's opinion of his liege by 30, and the liege's opinion of him by 20. It lasts for two years.
The mission has a failure state with an MTTH of 293 to 38, maxing out at 13+ Diplomacy. It will reduce the liege of the character you were trying to get to dissent's opinion of you by 25, and your chancellor might be imprisoned. The opinion modifier lasts 2 years.

Like Improve Diplomatic Relations, this is usually not very useful due to its short effect. However, it can be quite effective if a strong character is already close to rebellion, and could be enough to tip him over the edge.
All in all, I would say that Fabricate Claim is the most useful mission the chancellor has, but Sow Dissent can be quite useful if used wisely. If you have absolutely nothing for your chancellor to do, you might as well have him Fabricate Claims, then let them go every time to gain a bit of piety.

Marshals
A marshal is the leader of your army, and his abilities are based on his Martial attribute. He will make your troops withstand more damage and recover morale quicker, and he'll boost your military tech growth.
He has three missions he can go on: Suppress Revolts, Train Troops, and Research Military Tech.

Suppress Revolts directly decreases revolt risk by as many percent as the marshal has martial points. It also increases your chance of arresting anyone by as many percent. While the rebel risk part is not very useful as rebels are seldom a threat, the effect on arrests can be quite useful.
The mission has no associated events.

Train Troops increases levy size in a single province by 2.5% per point of Martial, and levy reinforcement rate by 5% per point of Martial.
The mission has two associated events. The first has an MTTH of 293 to 38 months, at its lowest at 13+ Martial. If it fires you'll get a 50% higher levy reinforcement rate in the province for a year.
The other event has an MTTH of 586 to 76 months, maxing out at 13+ Martial. It can only fire if a ruler in the province is either Ambitious or Deceitful. It'll reduce the levy reinforcement rate by 200% for half a year.

The final mission is Research Military Tech. It will increase military tech growth by 5% for each point of Martial. The mission has two associated events. The first has an MTTH of 586 to 76 months, maxing out at 13+ Martial. If it fires the Marshal will get the wounded trait, or with a 25% chance, the maimed trait.
The second event has an MTTH ranging from 2441 to 316 months, at its lowest at 13+ Martial. If it fires you'll get 0.1 progress in a random military tech in your capital.

Overall I'd say Research Military Tech is the most useful mission. However, Suppress Revolts can be great if you need to imprison someone, and Train Troops can work out well if you have multiple holdings in a province, and can thus reap its benefits multiple times.

Stewards
Stewards help you with your economy, and their abilities are based on their Stewardship skill. They will increase your demesne income and speed up you economical tech growth.
Your steward has three missions he can go on: Collect Taxes, Oversee Construction, and Research Economical Tech.

The first, Collect Taxes, simply increases tax income in the targeted province by 2.5% per point of Stewardship.
The mission has three associated events. The first has an MTTH ranging from 879 to 114 months, at its lowest at 13+ Stewardship. It will give you a lump sum of money based on your income.
The second event has an MTTH ranging from 586 to 14 months, maxing out at 13+ Stewardship. It is halved by a revolt risk over 10% in the province, again if over 20%, and reduced by 25% if the province is of a different culture. If it fires your steward will either get away safely, get wounded, or get killed.
The third event has an MTTH ranging from 586 to 24 months, maxing out at 13+ Stewardship. It is reduced by 25% by a revolt risk over 10% in the province, again at 20%, again if it is not of your culture, and again if it is not of your religion. If it fires it will increase revolt risk in the province by 10% for a year, and reduce the opinion of all rulers in the county of you 10 for a year.

The second mission, Oversee Construction, reduces construction time in the province by 2.5% per point in Stewardship.
The mission has two associated events. The first has an MTTH of 1172 to 152 months, at its lowest at 13+ Stewardship. If it fires it will make your Stewardship reduce construction time by another 5% in whatever county he is in. The effect is permanent, but bound to your steward, not the county.
The second event has an MTTH of 293 to 38 months, at its highest at 13+ Stewardship. It can only fire if a ruler in the province has an opinion under -20 of you. If it fires construction in the province will be 30% slower for a year.

The final mission, Research Economic Tech, increases economical tech growth by 2.5% per point of Stewardship.
The mission has no associated events.

As with the marshal, I find the Research Economic Tech mission preferable. However, the other two can be useful if you have multiple holdings in a single county.

Spymasters
Spymasters are in charge of your illegal activities, and try to protect you from such activities instigated by other characters. His abilities are based on his Intrigue skill. He's the only councilor that can be female, but only your spouse or mother (or any male) are eligible. He increases your chance of detecting plots, your plots remaining undetected, your chance of imprisoning or assassination someone, and your chance of avoiding imprisonment and assassination.
Your spymaster has three missions he can go on: Uncover Plots, Build Spy Network, and Study Technology.

The first mission has no direct effect, but two associated events.
The first event has an MTTH of 293 to 38 months, and is at its lowest at 13+ Intrigue. It can only fire if someone in the province is plotting against you or someone else. If it fires, it will reveal a random plot someone in the province has, or your spymaster will get murdered. Useful if you suspect someone is plotting against you. If not, the most useful place to do it is in your capital, as your courtiers and family members will often plot against you.
The second event has an MTTH of 293 to 38 months, and is at its highest at 13+ Intrigue. It can only fire if someone in the province is plotting against you or someone else. If it fires, your spymaster will either get away safely, get wounded, or die.

The second mission increases assassination chance in the province by 0.5% for each point of Intrigue. It also has two associated events.
The first event has an MTTH of 586 to 76 months, at its lowest at 13+ Intrigue. It can only fire if a ruler in the province both has a lower than 0 opinion of you, has at least one vassal himself, is male, and is homosexual (secretly or not). If it fires you'll have the option to blackmail him, spread rumors, or do nothing. If you blackmail him you'll either get 100 gold, have your spymaster assassinated, or have him exposed as homosexual. If you spread rumors you'll either have your spymaster assassinated, or him exposed as homosexual.
The second event has an MTTH of 586 to 76 months, at its lowest at 13+ Intrigue. It can only fire if a ruler in the province has an opinion of you below 0. If it fires you'll be able to accuse the ruler of corruption, or do nothing. If you accuse him he'll either kill your spymaster, give you 50 gold, or be exposed as homosexual.
The mission is pretty useful if you want to assassinate or discredit someone.

The third mission, Study Technology, has no direct effect, but two associated events.
The first event has an MTTH of 1172 to 152 months, at its lowest at 13+ Intrigue. It can only fire if the county has a higher tech level in some tech than your capital. If it fires you'll gain 0.1 progress in a random tech they have that is better than yours.
The second event has an MTTH of 293 to 38 months, and is at its highest at 13+ Intrigue. It can only fire if a ruler in the province has an Intrigue of 10+ or a spymaster with an Intrigue of 10+. If it fires your spymaster can get imprisoned, and it will hurt your relations with the ruler of that realm.
As the benefit of this mission is so extremely low, I would only recommend using it if you want to get rid of a vassal.

Overall Uncover Plots is likely the most useful, as it will help you protect yourself against your noble's plots. However, you'll probably discover many more plots passively than by using the mission. The Build Spy Network mission is very useful if you want to assassinate someone or discredit them. Study Technology is only useful for getting rid of problematic vassals.

Court Chaplains
Your court chaplain is your religious adviser. He'll improve your prestige and your technology growth rate. His abilities are based on his Learning skill.
He has three missions he can go on; Head Local Inquisition, Research Cultural Tech, and Improve Religious Relations.

The first mission has no direct effect, but five associated events. The first event was covered in the section on religious spread in my installment on religion.
The second event has an MTTH of 1172 to 21 months, at its lowest at 13+ Learning and 80+ moral authority. It can only fire if someone in the province is not of your religion. If it fires the character is converted to your religion.
The third event has an MTTH of 1172 to 21 months, at its highest at 13+ Learning and 80+ moral authority. If it fires your court chaplain will either safely get away, get wounded, or die.
The fourth event has an MTTH of 2344 to 43 months, at its lowest at 13+ Learning and 80+ moral authority. It can only fire if any ruler in the province has a piety under 100. If it fires, a random ruler in the province is accused of heresy, and you'll have the choice to either agree that he's heretic, or disagree. If you agree, he'll become a heretic, and dislike you. If you disagree, he'll like you more, but your court chaplain will get annoyed.
The final event has an 2344 to 43 months, at its highest at 13+ Learning and 80+ moral authority. If it fires, revolt risk in the province increases by 10% for a year, and the rulers in the province get -10 opinion with you for a year.
This mission is the only way to convert counties, and the most reliable way to convert characters. Do note that what religion they end up as is based on your court chaplain, so don't appoint a heretic/infidel as your court chaplain.

The second mission increases cultural tech growth in the province by 2.5% per point of Learning. It has two associated events.
The first event has an MTTH of 2441 to 316 months, at its lowest at 13+ Learning. If it fires you'll get 0.1 progress in a random cultural tech in exchange for some gold.
The second event has an MTTH of 2441 to 316 months, at its lowest at 13+ Learning. If it fires your court chaplain will become heretic, and ask you to join him. You'll have the choice of either becoming heretic, or imprisoning him.

The final mission has no direct effects, but has two associated events.
The first event has an MTTH of 1758 to 32 months, at its lowest at 13+ Learning and 80+ moral authority. If it fires it will increase the opinion of a random priest in the province towards you by 25 for two years.
The second event has an MTTH of 586 to 76 months, at its lowest at 13+ Learning. If it fires it'll reduce the opinion of a random priest in the province towards their religious head by 20 for two years.
This mission is pretty good if you need to improve your relations with the Pope.

Overall the Inquisition mission is probably the best, as the penalties for wrong religion are severe. However, your vassals will generally be able to do this on their own, so you could instead concentrate on cultural tech. The increase religious relations mission is nice if you need better relations with the pope.

Summary
Good councilors will make ruling your realm much easier, and so will using them in a good way. My tips are as follows:

• Get as good councilors as you can
• The research missions are often the best
• Fabricate Claims if you don't have a better way to gain claims
• Sow dissent if an enemy vassal is close to rebelling
• Use Suppress Revolts if you need to imprison someone
• Oversee Construction, Collect Taxes, and Train Troops can be useful if you have multiple holdings in a county
• Uncover Plots in your capital is often a good idea
• Use Build Spy Network if you want to kill or discredit someone
• Use Study Technology if you want to get rid of your spymaster
• Use Inquisitions if you have infidel/heretic counties
• Increase Religious Relations is good for getting the Pope to like you

 

[Meneth]

Breeding; Eugenics For A Better Future
First posted here.

Your children are extremely important, as one of them will usually take over upon your death. To ease the succession and subsequent rule, you want to prepare your potential heirs for the throne. One important ways of preparing your heir for the throne is by making good decisions even before he has been conceived. As large parts of the birth system are from what I've seen hardcoded, more of this installment will be based on personal experience than usual, rather than on the game files themselves. I'll go into how breeding works, and what you can do to affect it.
As always, there's a summary at the end.

Basics of Breeding
Depending on your and your spouse's fertility, you're more or less likely to have children. Two months after conception you'll be notified. Approximately seven months later, a child will be born. Essentially everything is decided upon birth, not conception; your child's gender and hereditary traits. Gender is a simple 50-50 split. Hereditary traits however seem to be a bit more complicated.
As the code for hereditary traits seems to be in the .exe itself, how exactly it works is not something I can find out. I can however base it on personal experience. From what I can tell, hereditary traits are based merely on two factors: The hereditary traits of the parents, and how similar their genetic material is.

DNA
From the save-files we can know that every single character in the game has a DNA value attributed to them. Further study shows that a character's DNA is based on a combination of their father and mother, with a small degree of mutation. For example the DNA values "dgfhibhieeh" and "jgagiicckmi" combined to create "dgfgibccepi", taking the first, second, third, fifth, sixth and ninth letter from the father, and the rest with the exception of the 10th from the mother. It can further be assumed that negative hereditary traits become more common the more letters of the DNA strings are shared, while positive traits become less common. This is likely graded through some sort of scoring system, as the congenital traits have no value assigned to them beyond their effects. It can be assumed that the worst of the congenital traits only become common when many letters of DNA are shared, while the most positive congenital traits are at the other end of the spectrum.
As every character has eleven letters of DNA, it is reasonable to assume that five are taken from the father, five from the mother, and one is random. From the save-files we can also see that no letter higher than 'p' is used; there are 16 characters in use. Due to this it is unlikely that any random character will have more than one or two characters in common with you, and based on this, one shared character likely has little or no penalty. Thus we can calculate how far away from you in your family tree for only one character to be shared. As five characters are inherited every generation out of 11, we thus get three separations before most characters share only one letter with you. As such I would recommend at least four degrees of separation whenever breeding within your family tree. Thus if you share grandparents (2 degrees of separation each way, for a total of 4) for example, marrying is unlikely to negatively affect any children you might have.

Congenital Traits
There are several congenital traits. These seem to be inherited about 50% of the time, and it is likely the presence of one prevents its opposites from presenting due to inbreeding. Below I've compiled a list ranked roughly from worst to best.
Negative:

• Imbecile: -8 to all traits, -10 opinion with all vassals, -30 opinion with anyone of the opposite sex. Opposed to slow, quick, and genius
• Inbred: -5 to all traits, -30% fertility, -1.5 health, -20 opinion with all vassals, -30 opinion with anyone of the opposite sex
• Slow: -3 to all traits. Opposed to imbecile, quick, and genius
• Syphilitic: -1 to all traits -2 health, -20% fertility, -30 opinion with anyone of the opposite sex
• Weak: -1 martial, -1 health, -5% fertility, -10 opinion with all vassals, -10 opinion with anyone of the opposite sex. Opposed to strong
• Hunchback: -1 martial, -5 opinion with all vassals, -30 opinion with anyone of the opposite sex
• Dwarfs: -1 martial, -30 opinion with anyone of the opposite sex
• Ugly: -1 diplomacy, -20 opinion with anyone of the opposite sex. Opposed to fair
• Clubfooted: -1 martial, -10 opinion with anyone of the opposite sex
• Harelip: -1 diplomacy, -10 opinion with anyone of the opposite sex
• Lisp: -1 diplomacy, -5 opinion with anyone of the opposite sex
• Stutter: -1 diplomacy

Positive:

• Fair: +1 diplomacy, +30 opinion with anyone of the opposite sex. Opposed to ugly
• Strong: +1 diplomacy, +2 martial, +2 health, +10% fertility, +10 opinion with all vassals, +10 opinion with anyone of the opposite sex. Opposed to weak
• Quick: +3 to all traits. Opposed to imbecile, slow, and genius
• Genius: +5 to all traits, +5 opinion with all vassals Opposed to imbecile, slow, and quick

As the positive traits are quite rare, you should go out of your way to obtain them. With a little bit of luck they could end up staying in your family for a long time. It might even be forth breaking the 4 degrees of separation rule for Strong or Genius, but I'd recommend still keeping at least two degrees of separation, preferably three.
On the other hand you should avoid negative congenital traits whenever possible, especially the worse ones. With a bit of bad luck they could end up plaguing your family for generations to come. Further, if you somehow end up with one of them it might be a good idea to, if possible, marry someone with a positive trait opposed to it, as that likely decreases the chance of your heir having it.

Summary
Make good decisions even before your heir is born, and you'll have an easier time when he takes over. My tips are as follows:

• If you can, avoid marrying within your family tree
• If you still want/need to, maintain at least four degrees of separation when marrying whenever possible. Sharing grandparents or any separation higher than that should be fine
• Avoid marrying anyone with negative genetic traits
• Do try to marry someone with positive genetic traits
• If you get a negative genetic trait, marry someone with a positive trait opposed to it (E.G., Quick as opposed to Slow), it should decrease the chance of your heir getting the negative trait

 

[Meneth]

Education; Avoiding Idiocracy
First posted here.

The previous installment was on the topic of breeding. The logical thing to cover now is therefore education, as together the two form your heir and strongly affect the success of your realm. Like with breeding, much of the code for education is hardcoded, and as such much of this installment will be based on personal experience rather than the game files. I'll go into how education works, and how to get the most out of it.
As always, there's a summary at the end.

Basics of Education
A child's traits and attributes are heavily influenced by what happens before they're of age, and at this time there are two characters that have a strong effect upon the child: the primary parent and the child's guardian. The primary character is decided by what type of marriage the child is a result of; if it is a patrilineal marriage the father is the primary parent, and if it is a matrilineal marriage the mother is the primary parent.
The primary parent will continue to have an effect upon the child until the child gets a guardian, usually at the age of 6. At that point the guardian takes over for near all purposes until the child comes of age at 16.

Base Attributes
One of the things a parent/guardian will affect is base attributes. A child will gain base attributes more quickly in an area the parent/guardian is skilled at than one which he's bad at. Thus children will often end up with a distribution of base attributes quite similar to their parent or guardian.
However, like most things in the game, this seems to work based on mean times to happen, so it is possible, though rare, that a child will get a distribution of base attributes quite different from his/her parent and guardian.
Due to how acquisition of base attributes work, I would recommend assigning a guardian with high attributes to your child.

Traits
The other area the parent, and especially the guardian, has a large effect upon is traits. Every year the child will get a trait event where the guardian makes a choice; usually either giving the child a trait outright, or a percentage chance of various traits. What events show up are primarily based upon the current traits of the child; good traits make further good traits rarer, while bad traits make further bad traits rarer. What the guardian chooses (if the guardian is not the player itself) depends heavily upon what traits he has. Some options will be (un)locked based upon his traits, while others are merely made more or less likely. A guardian will generally encourage the child to have traits similar to himself, and discourage traits opposite to him.
A Just guardian for example is therefore very likely to give the child the just trait, while an Arbitrary guardian will almost never do so.
Due to this I would recommend assigning a guardian with traits you find desirable, or putting yourself as your child's guardian, thus getting full control over the event choices.

Education Traits
Every character gets an education trait upon coming of age. For each attribute there are four levels, ranging from mediocre to great. The highest level improves that attribute by a large amount, and is thus highly desirable. What education trait a character gets seems to be semi-random; it seems to be based upon a mix of the guardian's education trait, the child's attributes, and some randomization. A child will very often end up with the same area of education as his guardian, and often at the same level as well.
Therefore you should especially pay attention to what education trait a potential guardian has, and choose one with one suitable for your child.

A Few Things To Watch Out For
Do note that if a child's guardian is of another religion or culture, the child might switch. Thus unless you actually want to switch religion/culture, avoid guardians of other religions/cultures. This happens more often if the guardian is Diligent for both culture and religion, more often for religion if Zealous, and more often for culture if Gregarious. The antitraits have the opposite effect.
If you want to groom your grandson or similar, note down when their 6th birthday will be. Pause on the very day they become 6 years old. You'll thus have an opportunity to ask for guardianship, and are likely to get it. You can thus groom your future heir, or ensure that a potential rival ends up with horrible traits, thus eliminating that threat.

Summary
Choose well, and your heir can end up with great attributes and traits. Choose poorly, and he'll likely end up mediocre at best, and succession will often be problematic. My tips are as follows:

• High attributes are desirable in a guardian
• Good traits are desirable in a guardian
• A good education trait is desirable in a guardian
• Alternatively, put yourself as the guardian, it'll give you a lot of control over his development
• If you want to be the guardian of someone not in your court, pause on their 6th birthday and ask for guardianship
• Avoid guardians of another culture and/or religion

 

[Veldmaarschalk]

Table of Traits

Table of Traits
First posted here.