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HOI4 Dev Diary - Combat and Stats changes

Hi everyone and welcome back to another dev diary! Today is about various changes that affect combat and units. With the Barbarossa update we want to shake up the meta a bit and also change a few stats and other aspects to make using the tank designer more interesting and rewarding.

High Command bonus changes
For a long time now unit bonuses from high command have confused people. Most expect that they apply to battalions, when in fact they apply only if their target unit type was “the majority type”, which was basically a weighted type count. They also could overlap, so infantry, mountaineers and artillery would apply to the same units letting you stack stuff in ways that was never intended and quite unintuitive.

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This system has now changed, and divisions get bonuses based on their composition, this is a straight up ratio based on the number of non-support battalions of each type, so a 2x artillery 3x infantry division will be 40% artillery 60% infantry.
Battalions are always classified as a single type for this (even though some are scripted with multiple types) based on this priority:
cavalry > armor > artillery > motorized > mechanized > infantry

The exceptions being rocket & special forces, which both act as an addition, so if the 3 infantry divisions in the example above were mountain units, then the division would also be 60% special forces and if the 2 artillery are nebelwerfers it'd also be 40% rocket

When counting the battalions of armies (ie when we have an actual unit and not only a division template), battalions that lack equipment will count as less, so a Light Tank battalion with only half it's tanks will count as 0.5 battalions (and not count at all if without tanks). The total sum of the compositions will still end up 100% (unless every battalion is without equipment).

Screenshot_3.png


To make it easier to see this we now have an indicator in the division windows showing the breakdown.

Combat Width
As a part of our efforts to shake up the 40/20 width meta, we have made changes to the combat width of province terrain. Province widths now range from 75 to 96. Plains have a new base combat width of 90, while Mountains have a new combat width of 75. Most of these widths will not divide into each other easily, hopefully moving the ideal width away from multiples of 10.

Urban provinces are now the “widest” with a width of 96. But this does not mean they will be the easiest provinces to overwhelm. Mountains, marshes, and urban provinces now have reinforcement widths of ⅓ of province width instead of ½. This should hopefully give these provinces a slight defensive buff, while allowing us to open up pushing power in the more open tiles.


Screenshot_2.png


In conjunction with these changes, we have also been looking at reducing the overstacking penalty. We hope that this will alleviate some of the need to have divisions that are the perfect width for a given province. But at the same time, smaller countries should now be able to specialize their division width to suit their home terrain more appropriately.

Breakdown (numbers not final etc etc)
  • Plains
    • Standard 90
    • Reinforce 45
  • Desert
    • Standard 90
    • Reinforce 45
  • Forest
    • Standard 84
    • Reinforce 42
  • Jungle
    • Standard 84
    • Reinforce 42
  • Hills
    • Standard 80
    • Reinforce 40
  • Marsh
    • Standard 78
    • Reinforce 26
  • Urban
    • Standard 96
    • Reinforce.32
  • Mountain
    • Standard 75
    • Reinforce 25
One of the major things that make larger divisions like 40 width armor hit disproportionally harder than smaller ones is also how targeting and damage works inside combat in relation to the enemies defense. Essentially the larger divisions make more efficient use of concentrated damage as it punches through defense. To solve this we are doing a few things. First of all we are weighting the targeting towards wider divisions being more likely targets and also when picking targets to try and match it to have wider divisions spread damage over smaller rather than always concentrating it. They will probably still hit harder, but combined with width changes and other downsides of larger divisions it should make it less clear cut.
However, this part isn’t quite done yet though so I’ll cover it again in more detail in one of the “bag of tricks” diaries in the future when i see how it pans out, but I figured it needed to be mentioned now ;) That said though, to wet your appetites here is a little tease from a debug mapmode in development...
1620214309589.png


Armor and Piercing
Currently the effects of having stronger armor than the enemy can pierce, or being able to pierce an enemies armor are binary and give fixed bonuses. This meant that there wasn't really any benefit to have more armor than you needed to stop the enemies piercing, and also that being a single point of piercing under enemy armor was just as bad as having no piercing. So things were quite binary. With the tank designer coming we wanted to make it feel like your investments in upgrades were always worth it, so we are changing armor and piercing to have more gradual effects.

Armor > Piercing
  • Unit takes half damage (as it currently works)
Armor < Piercing and Amor > 0.75 * Piercing
  • Take damage between half damage to normal damage by difference in value
Armor < 0.75 * Piercing
  • The unit takes normal damage
Lets break this down with an example:
  • A panzer division has an armor value of 52
  • Its being attacked by an infantry division with some anti-tank guns. Their piercing is 60
  • If this was the old system this armor would be worthless and not reduce damage at all
  • Now because its close enough (between 60 and 45), so you get roughly half of the normal effect around 25% reduction of damage.

Reliability
For the tank designer it was important that reliability was more impactful if it was to be a good tradeoff with other aspects of design, so we needed to change it up (lest @CraniumMuppets 0% reliability tank monsters would take over the world). Now it will not just affect rate of loss in attrition but various other aspects:
  • Reliability affects losses from attrition like before
  • Reliability now affects org regain when moving, and also makes any weather related org effects more impactful when low
  • Lower reliability scales up all impacts from weather so if facing extreme weather a unit with low reliability equipment will suffer more of those weather effects
  • At the end of combat units with better reliability will be able to get back a certain amount of tanks etc to simulate that simple more reliable constructions would work better for battlefield repair and be less fragile when taking damage. So it's a bit like capturing enemy equipment in combat - but in reverse :cool:

Screenshot_4.png


Our goal is that this creates interesting tradeoffs when designing equipment and will make you have to consider if its worth switching a strategy focused on speed and firepower towards reliability when operating in bad weather and tough areas like the Russian winter or in northern africa or jungles.

Oh, and I figured now might be a good time to point out that there will be a future diary on weather changes and other cool related stuff, so these changes aren't completely in isolation. But one step at a time :)

But before we go, a few words about the studio...

Studio Gold
Hello everyone, my name is Thomas, but perhaps better known as @Besuchov here :)

As you saw here we have recently reorganized ourselves a little, moving from a big centralized Stockholm studio to splitting ourselves into Red, Green and Gold. This is mainly an internal org shift to make sure we keep our growing organization firmly focused around making good games. You shouldn't notice too many differences in the short term, we are still PDS making GSG on the Clausewitz engine, but it does mean that we can align each studio to the particular games. Since you will hear the studio names every once in a while, I just wanted to say who I am and what the studio is responsible for.

My role is Studio Manager, which means I'm accountable for the long term success of Studio Gold and working with things like management, staffing, and long term plans. Studio Gold has as its main focus Hearts of Iron (but we may or may not have some secret other stuff as well). Directly making the games though, that's still the job of Podcat and the team, but I intend to do my best to create an environment where we have the best chances to make great games together.

For me this is coming full circle at Paradox. I started as a programmer in 2004 and one of my first tasks was to work on Hearts of Iron 2. Since then I've done various things including being lead programmer for Hearts of Iron 3 (and Victoria 2), Project Lead for EU4 and more recently Studio Manager for PDS. Next to EU, HOI is my favorite game and I'm delighted to be back in a place where I can focus on fewer games and where that game is Hearts of Iron. You will see more of me in the future even though I will mostly take a backseat to the team working on the game.

That’s all, see you all again next week for more dev diary goodness!
 
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It's been a while since I played HOI4, but what exactly is reinforce width? How much width can be on reserve? Or how much of the reserve can reinforce at once? Or something else?
Reinforce width is how much width is added to the battle per extra attacking flank. For example, in the current version most combats are 80 width as a base. Attacking from two directions adds 40 extra width, so 120 width. Then 160, and so on for each extra direction you attack from.
 
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Not quite sure if these changes are good or not but I suppose combat did need a rework. Looking forward to the next DD.
 
Great dev diary. My group has made it their mission to try out strategies in competitive games to "upset" the meta, eventually making an overhaul mod that aims to prevent straight metas like vanilla. Really glad that land combat is being reworked to avoid the extreme min/max meta we're in right now. More in-depth combat systems and modifiers are always welcome! Really looking forward to this update.
 
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Regarding piercing, I don’t see why people are up in arms with pierce < armor being binary.

if your at shell can’t pierce, it can’t pierce. It doesn’t matter how close you were, if you can’t—you can’t. Now once you approach the threshold where a shell of size X can pierce in certain circumstances, you begin to be able to pierce. As the shell size increases, or shape charges are invented, the odds you you piercing go up until you can reliably always pierce the enemy armor. But so long as you can’t meet that minimum threshold of being able to pierce at least *some* of the time, it doesn’t matter how close you were—you still can’t pierce.

also re: division templates. I don’t think the intent is for a single nation to be making a template for each terrain type for both infantry and armor. I think the intent is for a 24 width template and a 20 width and a 25 width and a 30 width to not result in wildly different outcomes. As it is now, everyone independent of country or terrain reality is incentivized to run with 10w, 20w or 40w templates. If you deviate you’re gonna get wrecked. There will likely be a catch mall template that savvy USA Germany, UK and USSR players will field when fighting in N Africa and Europe. But if a player decides they want 3 arty battalions, 9 infantry battalions and doesn’t want to invest in an AT battalion their disadvantage isn’t the width, it’s the combat stats that additional arty battalion brings coupled with the disadvantages of no AT battalion. These width changes seem to jointly disincentivize 40w while also making width less dogmatic.
 
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One of the better ones, very promising!

Because generally there are about a thousand ways you could pierce/ or immobilize, and about a thousand ways one could bounce. In extreme caliber cases you could say it's binary, but distance and angles play a huuuuge part. Also wear and tear.
 
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It is not an immediate eye-candy change - but people will realize that you have created a gem here.
Maybe that is why people a little skeptical at first - or because it requires better reading of the terrain and weather impact.

The historical players are able to model divisions and armies that are far closer to historical compositions. Combined arms, baby!
Alternate history players will realize that they can create the wildest unit templates and take them to the field.

Plus, as some mentioned already, the unit can be modified to adapt to terrain (tanks do not well in woods or urban areas, infantry can be overwhelmed in open plains by motorized units, etc.)

Well done, Paradox, well done! This is a step into a more tactical/strategical game concept. Love it already.
 
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From how I read forum here, it looks like, that todays min-maxers spending tons of time constantly changing generals with different terrain bonuses and division templates between marines/tanks/SH tanks/mountaniers according to current terrain.
 
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Reliability
For the tank designer it was important that reliability was more impactful if it was to be a good tradeoff with other aspects of design, so we needed to change it up (lest @CraniumMuppets 0% reliability tank monsters would take over the world). Now it will not just affect rate of loss in attrition but various other aspects:
  • Reliability affects losses from attrition like before
  • Reliability now affects org regain when moving, and also makes any weather related org effects more impactful when low
  • Lower reliability scales up all impacts from weather so if facing extreme weather a unit with low reliability equipment will suffer more of those weather effects
  • At the end of combat units with better reliability will be able to get back a certain amount of tanks etc to simulate that simple more reliable constructions would work better for battlefield repair and be less fragile when taking damage. So it's a bit like capturing enemy equipment in combat - but in reverse :cool:

Our goal is that this creates interesting tradeoffs when designing equipment and will make you have to consider if its worth switching a strategy focused on speed and firepower towards reliability when operating in bad weather and tough areas like the Russian winter or in northern africa or jungles.
Has the possibility of changing the stat used as the "currency" of upgrading the model been discussed?
I know I've made a suggestion regarding replacing the current model of changing a drop in reliability in order to increase other stats, with increasing production cost to upgrade the stats, possibly with a decrease to production cost in exchange for lowered reliability.
I think this would make this aspect of the game more realistic.

Especially as regards to the decision/doctrines of quantity vs quality, which under the current system is only represented by throwing more factories at the tank being produced.
 
Could there be a possibility of a plundering system being added in? For example Axis nations can plunder the territories of conquered nations gaining more industry in the process, but in turn those territories would become more difficult to deal with.
This mechanics is already here with "Harsh Quotas"
 
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This mechanics is already here with "Harsh Quotas"
Problem is Axis countries don't use these occupation laws, which leads to them getting compliance in all occupied areas. It doesn't seem logical to me why Hitler would allow Civilian Oversight in France, or Belgium, or The Netherlands, or Denmark, or the USSR, but you get the point. This is a bit off topic because this thread is not talking about resistance and compliance, but I do believe it would balance the point Azores did if they just made fascist countries more inclined towards using more agressive occupation laws.
Example : Japan using Forced Labor as historically, Germany using Brutal Opression in Poland, AI making a mix of Local Police Force and Secret Polices in some provinces would also be nice, I also think a small rework of Reichskomissariats would fit this point really well, but it'd be tricky to pull off as despite their provinces being cores they still had strong resistance IRL, I tought of something like them ceding stuff to Germany and losing their cores and eventually having to deal with resistance.
 
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Problem is Axis countries don't use these occupation laws, which leads to them getting compliance in all occupied areas. It doesn't seem logical to me why Hitler would allow Civilian Oversight in France, or Belgium, or The Netherlands, or Denmark, or the USSR, but you get the point. This is a bit off topic because this thread is not talking about resistance and compliance, but I do believe it would balance the point Azores did if they just made fascist countries more inclined towards using more agressive occupation laws.
Example : Japan using Forced Labor as historically, Germany using Brutal Opression in Poland, AI making a mix of Local Police Force and Secret Polices in some provinces would also be nice, I also think a small rework of Reichskomissariats would fit this point really well, but it'd be tricky to pull off as despite their provinces being cores they still had strong resistance IRL, I tought of something like them ceding stuff to Germany and losing their cores and eventually having to deal with resistance.
This should be an option since not all games are historical. I don't know if the AI also does the historical policy in regards to this, but if you want to force it in MP, the server might put it in the rules, or lock the country to certain policies.
 
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Option 2 is what almost every army actually did in the real war. The Germans with their thousands of different KStN tables feeding a rainbow menagerie of divisions were highly unusual in this regard, probably much to the detriment of map table planning where the counter signifying "division" could mean wildly different things based on its type. At the macro scale, standardization pays.
I mostly agree, here, but there were two important riders:

- It was often possible to split off single brigades for particular jobs, especially where terrain and supply were particularly harsh or troops in particularly short supply. An example would be North East Africa, both in the deep desert operations (by the Italians, especially) and for Ethiopia/Abyssinia (by the British, particularly Indian divisions).

- Ad hoc "units" of around brigade size were sometimes made for "emergency" situations. How to include this in the game I have no idea, but it was definitely done!
 
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Problem is Axis countries don't use these occupation laws, which leads to them getting compliance in all occupied areas. It doesn't seem logical to me why Hitler would allow Civilian Oversight in France, or Belgium, or The Netherlands, or Denmark, or the USSR, but you get the point. This is a bit off topic because this thread is not talking about resistance and compliance, but I do believe it would balance the point Azores did if they just made fascist countries more inclined towards using more agressive occupation laws.
Example : Japan using Forced Labor as historically, Germany using Brutal Opression in Poland, AI making a mix of Local Police Force and Secret Polices in some provinces would also be nice, I also think a small rework of Reichskomissariats would fit this point really well, but it'd be tricky to pull off as despite their provinces being cores they still had strong resistance IRL, I tought of something like them ceding stuff to Germany and losing their cores and eventually having to deal with resistance.
The problem with that is if you were to model the underlying reasons, you quickly wade into racial and ethnic hatred/superiority.

afterall much of hoi4 is a “what if”. One of the often used armchair general, hindsight is 20/20 of the Second World War is “what if hitler invaded the east as a liberator?”. Sure racial hatred and ethnic superiority is part and parcel of being hitler. But what about some ahistoric fascist expansionist power? Is fascist Canada necessarily going to have innate racial tension vs Americans they occupy? Afterall the ethnic background is largely similar between Canada and the US.
I could understand the ai in a historical game being locked into these harsh quota decisions, but locking the player or alt history fascists into it seems off the mark.
 
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This should be an option since not all games are historical. I don't know if the AI also does the historical policy in regards to this, but if you want to force it in MP, the server might put it in the rules, or lock the country to certain policies.
Yes, I mean for example leaders would affect how willing the country is to use harsh occupation laws, so for example, the Kaiser in Germany would not be as willing as Hitler in Germany to use Brutal Opression, just an example. But I do agree. It is more complicated than what I just said, so I failed to communicate.
 
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Jamor is absolutely right when he states that width of a unit depends on the terrain. I am glad we are getting away from this.

Stalingrad is an example for urban warfare. It had a population of about 440000 people in 1940.
During the battle of Stalingrad, Germany had 850000 solders in the field around Stalingrad (not all combat units, but 1/3 combat to 2/3 supply is a fair ratio), and the Red Army about 1700000.
Total losses (including wounded and prisoners):
- Germany: over 180000 dead and 110000 prisoners (of which 6000 returned - the most likely died as well), plus 550000 other Axis
- Soviet: 1100000 (over 500000 dead)
It was an absolute meat grinder.

Battle of France where a few German armored divisions split France in two parts:
In the field:
- Germany: 3350000
- Allies: 2860000
Losses:
- Germany: Approximately 50000 dead
- Allies: 360000 dead, 1900000 prisoners

Someone is still of the opinion that terrain and terrain adaptability has no impact on combat width and resulting losses?
 
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Yes, I mean for example leaders would affect how willing the country is to use harsh occupation laws, so for example, the Kaiser in Germany would not be as willing as Hitler in Germany to use Brutal Opression, just an example. But I do agree. It is more complicated than what I just said, so I failed to communicate.
I agree, but I do not know if the AI already does this or not when historical or not.