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Oct 23, 2003
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Welcome all of you to this After Action Report! In this AAR I will provide a detailed insight into combat mechanics of the game. It is designed to help new and intermediate-skilled players fight wars in non-optimal conditions, specifically, against opponents that are larger and possibly better suited to war.

The tutorial is split into two parts: introductory chapters will explain how the combat mechanics work at all levels (national, war, battle). The second part will follow a very early game invasion of France during the Hundred Years War. By the end of this tutorial, a player should be able to hold their own in combat even when moderately outmatched (I can't promise you'll be able to crush France as Avignon on day 1, for example).

Note: This tutorial is meant to be a complement to Rhadok's excellent tutorial, An Empire Under the Sun, and thus, it is written under the assumption that you have read (and followed) that AAR, and are using the 4.1 beta patch (available here). If I mention a concept and don't expound on it, check there first before asking here. Your ability to fight wars when back-stabbed by the AI on multiple fronts and outnumbered 3:1 is greatly determined by understanding the other concepts of the game (especially economics).

Our objectives are very ambitious:
1.) Conquer Scotland
2.) Conquer Ireland
3.) Trigger the "Occupy Paris" mission for England, and gain cores on the Gallia region.
4.) Retake all cores in France (both those that England starts with on French soil, and those given by the Occupy Paris mission)
5.) Find at least one nation in Europe, claim their throne, and force a Personal Union.
6.) Become Holy Roman Emperor and start the process towards forming the Holy Roman Empire.

The concepts that we will cover are:
* Overall strategic concepts, such as Manpower, War Exhaustion, War Taxes, and War Capacity
* Army/Navy-wide concepts such as units, army composition, attrition, supply limits, and reinforcement
* War concepts such as sieges, assaults, looting, scorching the earth, blockades,
* Battle concepts such as terrain, using generals/admirals, combat phases, retreating, morale, and discipline.


Disclaimer: Due to the dynamic nature of the engine used to make EU3, I can't give you step by step instructions on most actions, as the AI is not completely predictable, and the entire point of the event and decision engine is to create a historically plausible framework that doesn't run on rails. If you run into something odd, don't hesitate to ask here, or on the main forum.

Table of Contents

Note: Please don't let me forget to update the ToC. I'm horrible about it my AAR's. :)

Combat explanations (no game play)

Chapter 1: Maintenance and Units
Chapter 2: Morale and Discipline
Chapter 3: Supply and Attrition
Chapter 4: Manpower and Reinforcement
Chapter 5: Battles: Understanding Combat (basic)
Chapter 6: Battles: Understanding Combat (advanced)
Chapter 7: Naval battles and Blockades

The Hundred Years War (game play) - scroll down to Chapter 8

Chapter 8: The Conquest of Scotland - 1399 - 1401
Chapter 9: The Conquest of Ireland - 1401 - 1402
Chapter 10: The Occupation of Paris, part 1 - 1402 - 1404
Chapter 11: The Occupation of Paris, part 2 - 1404 - 1405
Chapter 12: The Occupation of Paris, part 3 - 1406 - 1407
Chapter 13: A Stake Through the Heart - 1407 - 1408
Chapter 14: Crushing Burgundy, part 1 - 1408 - 1409
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Chapter 1
Maintenance and Units

For this section of the tutorial, since we're not doing anything yet, we're going to step in our time machine...

Open EU3 Single Player mode, and when the map of the world in 1399 is displayed, click on the Revolutionary France bookmark on the left hand side (I've added a red arrow to show where I'm talking about - you may have to scroll down, depending on your resolution).


Once you select the bookmark, you'll see the date jump to 14 July, 1789, and the map drastically changes to show the world's borders on that date. Select Prussia (second "interesting country" in the list, or the gray country in Northern Germany) and click Play.

(Don't worry about options - we're not going to actually do anything here).

Using the bookmarks to play lets you jump into a scenario and play nations that already have selected National Ideas selected, appropriate buildings already built, and play against more developed AI nations. However, in this case, we just want to see units!

Click on Prussia's Coat of Arms in the upper left corner, and select the helmet and sword icon, to display the Land and Naval screen. Here, we'll talk about the backbone of our armed forces - technology, units and maintenance.



At the bottom of the Land and Naval screen, you can see your Land and Naval Maintenance. Maintenance is simple: your army likes being paid, but armies are expensive. Large armies are even more expensive, and if your nation expands its army outside its force limits, it gets significantly more expensive. To reduce costs, you can reduce the army's pay, with a corresponding drop in morale (-.02 morale per tick left on the slider in exchange for -0.5% pay, to a maximum of -2 morale in exchange for -half pay)

During war, you should always have 100% maintenance (all the way right) unless you have already crushed your opponents armies and are mopping up (or are beating down on a helpless minor). During peace, you should set your maintenance based on your experience and revolt risk - a conquering nation often has rebel problems, and thus, you'll need some additional maintenance to help keep rebels down. A nation that has no conquered provinces and no revolt risk can easily leave the slider at half pay (all the way left). --- If you forget to turn on maintenance while at war, a notification icon
will appear. Pay attention for it, lest you needlessly get your armies wiped out. ---

Underneath the stars, you'll see your nation's Force Limits for Land and Naval. Your Land force limits are based on your provinces tax base (thus, larger, wealthier nations have higher force limits), your Land/Naval slider position, and the Grand Army Idea. Your Naval force limits are based on the tax base of all ports (with a penalty for ports that have no land connection to your capital), your Land/Naval slider, and the Grand Navy Idea.

Your nation's Land force limits are rarely an issue - early in the game, you can't afford to go over the force limits, and later on, you should hopefully not need to. However, once you go over your force limits, the cost for new units and maintenance for existing units increases quickly!

On the other hand, a colonial nation is almost sure to go over their Naval force limits - it's not uncommon for an aggressive colonizer to require more ships for tariffs than your force limits would allow. Luckily, naval maintenance is relatively cheap!. Don't worry about your naval force limits.

--- Finally, protect your capital! If your capital comes under siege or is occupied, your force limits will drop immediately, raising the cost of your armies when you least need it. ---

Units and Modifiers

On the top half of our Land and Naval screen, we can see our units (and change our land units).

First, look at the numbers under Fire and Shock - these numbers are damage multipliers. As your technology level increases, these modifiers will increase.

Infantry: Infantry starts out with low shock and very low fire multipliers. Over time, fire will increase to pull even with shock, making infantry very balanced. However, Infantry will never be as good at shock as Cavalry, or as good at fire as Artillery.

Cavalry: Cavalry starts out with 0 fire, and twice the shock multiplier as Infantry. Over time, the shock multiplier increases so that cavalry will do anywhere from 2-3 times as much shock damage as infantry, however, as you can see, it will never do very much fire damage. Since the fire phase comes first, this can get very painful for our cavalry.

Artillery: Most nations can't even build artillery in 1399, and it's practically worthless in battle until land tech 23, when you get a unit with decent stats, and the fire modifier finally reaches something useful. We'll explain how to use artillery later, but notice its huge fire modifier here - as time goes on, artillery gets very powerful.

Under Units, you can see how many total units you have of that class - not how many units of the type selected!

Click on the infantry unit "Frederickan Infantry".


Here, we see the real reason I picked the Revolutionary France start - lots of units to show!

As you progress in Land Technology, you will unlock various improved units. Units generally specialize as being better at fire or shock, offense or defense, etc. The unit statistics are somewhat misleading, in that the attack and defense stat are not about who is attacking in the battle, but how much damage the unit will give and receive each day. --- Fighting a nation that has superior units available to it will put you at a severe disadvantage. ---

Look at Square Infantry:
8 Fire Offense / 10 Fire Defense
7 Shock Offense/ 8 Shock Defense
10 Morale Offense / 11 Morale Defense

The key here is that Square infantry has the best defensive stats available at this tech level. Impulse has better offensive stats. (We'll explain how the determine damage in Chapter 5 and 6)

If your nation has high discipline and morale, you are better off choosing a defensive infantry unit, especially since after Land Tech 23, you can add artillery to boost your army's defense. If your nation has low discipline and morale, you need to maximize offense to overcome your statistical deficiencies, and hope your opponent brakes first.

Select Square Infantry, and you'll return to the Land and Naval window. All of your units have now upgraded to Square Infantry. --- Don't ever do this during war without moving your armies to safety - all upgraded units will have their morale drop to 0 and take 3+ months to regenerate to full morale! ---

Go ahead and look at Cavalry and Artillery. For cavalry and artillery, the choice is simple: cavalry needs shock and morale offense, and artillery needs fire offense and defensive stats. Everything else is moot.

Managing units

Quick notes about building and managing units.

When you are building units in a province, the units you can build are based on the nations that have cores on the province (if you are technologically backward, this can let you build better units!). If you build a unit that is from your tech group, but not your primary unit, you can upgrade it later by switching to the built unit type, leaving the menu, then switching to the unit type you want to upgrade it to. --- Units from other tech groups cannot be upgraded! ---

Latin (Western European) tech has the best infantry. Eastern European, Ottoman, and Muslim tech has better cavalry at early tech levels, but this advantage tapers off over time.

Each tech group has its own cavalry:infantry ratio that is required to make use of the tactics modifier. As your tech increases, the tactics modifier can make a significant difference in reducing the damage your armies take, so try to stay under the ratio. Mouse over the Tech display (above your infantry unit) to see your modifier and ratio - Western Europe requires armies to have equal or greater amounts of infantry than cavalry. (We'll explain tactics more in Chapters 5 and 6)

Ships cannot be upgraded, and can only be built in a port that is your own core.
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I may have missed it, but I don't think you actually said what the tactics modifier is. I also have 4.0, as I would assume most new players do, and I don't see the "Western Unit Tech" thing, and so obviously can't see any cav:inf ratio. I think it could do with some explaining.

Otherwise, excellent addition to an already excellent AAR. Subbed.
I can see it in my 4.1 beta version. Mousing over it in my 1495 game as France, it promises me a combined arms bonus for having less than 50% cavalry in an army. I do agree that a little more explanation of the concept would be helpful.

Also, sterling work on this AAR. I'm learning a lot from this!
--- Fighting a nation that has superior units available to it will put you at a severe disadvantage. ---

As much of a disadvantage as if you come at somebody with a knife? :p

Huh. I guess they added that unit ratio thing (or at least the display of it) in the latest beta patch? Interesting.
Whoops. I better add that I'm using the beta, same as Rhadok's AAR.

The beta patch includes the Tech note and the tactics tooltip, along with a nifty red warning on your army to warn you when you're not getting the tactics bonus.

The tactics bonus will be explained when we get into details about battles (I'll update the chapter to note that).

Judas Maccabeus: Should I add the Octogon as an AAR goal? :)
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--- Don't ever do this during war - all upgraded units will have their morale drop to 0 and take 3+ months to regenerate to full morale! ---

While the morale loss can be important - in a long war, staying up to date with your units is even *more* important IMO. (and changing your units late in the month is always a good idea :) )
While the morale loss can be important - in a long war, staying up to date with your units is even *more* important IMO. (and changing your units late in the month is always a good idea :) )

I'll add the note "without moving your armies to safety". :)
Chapter 2
Morale and Discipline

While the units we picked above are important, and the generals we will talk later can affect an individual army, the two modifiers that will have the greatest impact on your ability to fight are Morale and Discipline.


Morale is a unit's ability to stay in the battle and fight. Note I say "unit" - morale is calculated individually for each unit in a battle, so that units will retreat from battle individually if they run out of morale. We'll explain morale loss in battles in Chapters 5 and 6.

Morale comes into play in several ways:
  • If you are outnumbered, the units on the edges will be attacked by multiple units. As they retreat, your line will slowly collapse.
  • If every unit in your army has 0 morale during a battle after the first 10 days, your army will automatically retreat in a direction not of your choosing.
  • If every unit in your army has 0 morale during a battle during the first 10 days, it will surrender, and you will lose the entire army!

    If you go back to the Land and Naval screen and mouse over the Land Morale stars (above your force limits), you will see the maximum morale of your units, and how that morale is calculated.


    For Prussia in 1789, our morale is pretty high (6.57), and is largely affected (in order of importance) by:
    Technology - as you gain tech levels, your maximum morale increases. In 1399, you gain no morale from technology!
    Maintenance - Your army's maximum morale increases by .02 per notch on the maintenance slider, with a maximum of 2. This, of course, increases how much you pay.
    Military Drill - Military Drill is a national idea that increases your morale by 1. Early in the game, where no one gains morale from technology, this is a huge increase. Later, it's nice but not as important.
    Ruler's Military Skill - You will gain .1 morale per point in your ruler's military rating.
    Sliders - Serfdom, Naval, and Defensive decrease morale. Offensive, Free Subjects, and Land increase it.
    Prestige - For every 2 points in prestige, you gain .01 morale. A nation with 100 prestige gains a full 1 point advantage over someone with -100 prestige!
    Advisors - Prussia does not have a Grand Captain advisor, but if they did, they would gain .05 morale per star rating.

There is one more very important modifier to morale: Bankruptcy! If you take out 5 loans and then fail to pay the interest, your nation will go bankrupt. Bankruptcy disbands all your mercenaries, halves your inflation, wipes out your loans, imposes a -2 modifier to morale, reduces your prestige by 100, and reduces your stability by 3. The -2 modifier for morale, especially early when you have few sources for morale, can make your armies and fortress garrisons literally worthless!

Morale's effect is a double edged sword - keep a wary eye on your own morale, and if you destroy an opponent's morale, go in for the kill!


Discipline is a multiplier to an army's ability to do damage. Every time your army does damage to an enemy (not morale damage), the damage is multiplied by your discipline.

Early in the game, the only discipline modifiers are your Quality/Quantity slider, and the Commandant advisor (+2% discipline per star rating). As the game goes on, there are decisions, ideas, and the Absolute Monarchy government that can further increase your discipline, increasing your ability to crush enemies under your boots.

Open the Coat of Arms, and click on the general picture (a man in a hat).


In the upper middle section, mouse over your discipline modifier (124% for Prussia), and you will see that you gain 4% discipline for your Quality slider setting of 2, and 20% disciplines from the Prussian decision "Prussian Military Reforms". Prussia's armies will cause 24% more casualties every day in battle!

While 124% sounds impressive, with more decisions (Militia Act), advisors (3 high ranking Commandants for 30-36%), and the Espirit d' Corps national idea (25%), players have managed to get nearly 200% discipline!

That said, discipline becomes much more powerful as the game goes forward, since your armies will simply not be able to do as much damage in 1399 as they can in 1799.

Thus, a simple summary: Morale is the will to fight, Discipline is the ability. A nation with high morale and high discipline is a fearsome foe!
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It is a pity that your excellent Monopoly AAR is currently on hold, but this AAR is no less superb. I may actually improve upon my meagre military ability in EU3 with this excellent advice! However...

Our objectives are very ambitious:
1.) Conquer Scotland

Are you mad?! Don't conquer land filled with drunken fools, it will spell the downfall of your nation!
Gather around kids... Professor naggy is about to teach us a thing or two. Outstanding presentation as usual.

Is it to early to nominate you to pick up the part of the AAR when the Reformation hits? :)
it's surprising you use Prussia to explain some concepts for the hundred years war ... :D

That's what really happened at Agincourt, don't you know. The English formed cavalry squares with flintlock muskets and bayonets. Poor French didn't stand a chance. :D
That's what really happened at Agincourt, don't you know. The English formed cavalry squares with flintlock muskets and bayonets. Poor French didn't stand a chance. :D

Yup. They'd have lost if the Prussian's hadn't arrived. :)
Another great update. Another small but important thing:

"it is written under the assumption that you have read (and followed) that AAR, and are using the 4.0 beta patch"

Anyway, is the tactics modifier new in 4.1b, or was it there already, but not shown?
Another great update. Another small but important thing:

"it is written under the assumption that you have read (and followed) that AAR, and are using the 4.0 beta patch"

Anyway, is the tactics modifier new in 4.1b, or was it there already, but not shown?

Whoops. Heh. The modifier is new to HTTT (so it's in 4.0), but is not viewable anywhere without the patch.