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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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The more I hear people argue against the width changes the more I like them. I bet, in all of WWII, there was never a situation where a division did not have enough frontage in combat to effectively use all of its strength... I like to minmax but what people are complaining about here is foreign to me. Because a realistic simulation is more important to me than having simple perfect strategies to get the absolute maximum out of every single division.

Worse yet, people are making assumptions about the combat system that has yet to be revealed in their attempt to counter the new changes.

If you want to play a game with perfectly defined moves, I suggest chess, checkers, or perhaps tic tac toe. This is a WWII simulation. I would argue it should be impossible to perfect every combat situation.
My thoughts exactly. I'm not looking in the game for a power fantasy of mercilessly conquering the map with Sabaton cheerleading me in the backround but having a realistic and challenging simulation of wartime strategy, logistics and diplomacy/politics.
 
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Well I am curious as to how these changes will play out.

I may be wrong, but I honestly don't understand why you would touch combat width.

Currently 40/20 width is most efficient. Changing combat width depending on terrain will shift the most efficient number to 32/16 or 36/18 or whatever number is optimal in the majority of cases.
In cases you don't have optimal width, you receive a penalty. This penalty will be lower than it is now, but still.
Are you going to design special divisions for specific terrain? Do you want to bother microing them to that specific terrain?

The only problem I see with the current 40 width division meta, is that damage allocation favours larger divisions over smaller ones. But that is being fixed anyway. So why the need to change combat width?

Do simply not want to bother getting every template to 40 width? Well, no need, with the damage allocation changes, a 10 and 30 width should perform the same as a single 40.
 
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I was referring to the concept that a division "partially" in a battle will still lose equipment like it's fully in the battle, just with less HP (so the effects are worse) in Hoi4. I don't think that IRL reserves "reserved" in the line of fire.
Changing it so that a division's HP are affected by over width penalties would be... a bizarre decision, on the developers' part. The part of the division that stays in reserve doesn't literally volunteer to die because some guy in the front line did... The disjunct between attacking power (being related to the combat frontage and thus to (roughly) the square root of the force size and defensive power being proportional to the total size of the force is what drives that fact that a skirmish between two brigades might typically last half a day (~8 hours), a combat between two divisions roughly a full day (~24 hours) and a fight between two corps around 3-4 days. Ie. bigger battles take longer because the bigger a force is the lower a proportion of it fights at any one time.

I like the "diminishing returns" part but not the massed attacks part. How did attacks interact with defense? Did it just effectively turn battles into one blob vs. another?
I suppose if that's an abstraction of how combat worked irl...
In a game where a single combat may cover several provinces and a corps or so on each side, any system is necessarily an abstraction. The battles happen over the 'defending' province(s) and all attacking provinces on the map (either the HoI2 one or a modded one, in the case of AoD).

The defence in AoD works as a reduction to damage via its ratio to the attack, rather than as a cutoff when attack > defence, but other than that HP always count at full value. As I said above, the square root attack to linear defence relation is what makes a 1 division-a-side battle much quicker than many divisions per side. The square root effect for attack also favours high attack value units (like armoured divisions) for attacks over standard/infantry divisions.
 
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Armor < Piercing and Amor > 0.75 * Piercing
  • Take damage between half damage to normal damage by difference in value
No that wouldn't have the same result at all. Your solution would just give AT a leg up and make it easier to pierce. There would still be a 50% damage drop off as soon as piercing drops just below the armor value. The damage curve would be the exact same. The curve would just be moved to the left or the right on said graph.

Example: Enemy division has 60 armor. Three divisions are matched up against it. One has 60.1 piercing, it does normal damage. One has 59.9 piercing, it has 50% damage reduction. One has no piercing, and also has 50% damage reduction. Does anyone see the problem now?

It is too binary. The division with 59 piercing should not receive the same modifier as the division with 0 piercing. Once again. Vehicles are not uniformly armored. If people think the division with almost enough piercing and the division with barely any piercing should deal similar damage to armored vehicles, that is fine. But, it is simply not true. The calculation should be more gradual than that on both sides of the armor value. The proposed changes fixed one side. Now they just need to fix the other. It should not take more than an hour of programming to change the formula.
If you read the top quote (taken from the Dev Diary itself) that's not the picture I get at all. The picture I get is:
  • Armour > Piercing = half damage
  • Armour < Piercing but > 0.75 * Piercing = a sliding scale between half and full damage
  • Armour < 0.75 * Piercing = full damage
Ie. a low plateau, a high plateau and a slope between with no discontinuities (no sudden drops or rises in damage). After that, it's simply a question of where you set the armour and piercing values (and, optionally, how much you scale piercing by for the top of the slope - I'm hoping that 75% figure will be moddable, and I certainly expect it to be tested and balanced).
 
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(i comment this a lot but) i really don't buy this. this guide for MP divisions has around 25 unique templates, not including variants (i.e. med/mech vs med/mot or 13/7 vs 12/8 vs 11/8/2 - that feels pretty varied to me! it's just that players get very used to them.
I do not think so. Most of these divisions are just small variations of basic division templates. They are not unique. Most infantry are variants of 10/0(9/2, 5/0...) and 14/4(including 11/6, 8/8...); Almost all tanks are variants of the basic 10/10(such as the 13/7 and 12/8, as well as 15/5.. etc).
 
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I would not think so.
what does this mean? i'm assuming it's just a language barrier thing, but i posted an opinion, that the templates feel pretty varied. either you agree with it or you don't, "would" is confusing. or are you referring to me saying i didn't include separate variants? i guess you can make an argument that 11/6 and 14/4 aren't unique, but they have vastly different purposes so i included both of them. otherwise it sounds like you're saying "they aren't unique because the infantry is always with artillery and the tanks are with mobile infantry" which is silly.
 
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what does this mean? i'm assuming it's just a language barrier thing, but i posted an opinion, that the templates feel pretty varied. either you agree with it or you don't, "would" is confusing. or are you referring to me saying i didn't include separate variants? i guess you can make an argument that 11/6 and 14/4 aren't unique, but they have vastly different purposes so i included both of them. otherwise it sounds like you're saying "they aren't unique because the infantry is always with artillery and the tanks are with mobile infantry" which is silly.
TBH, "would" is a wrong word to include in that sentence.

Let me correct myself then, I disagree with your opinion.
What I was saying that 11/6 is the same basic template as 14/4 that switches 6 widths of infantry to 6 widths of artillery, just like 14/4 is a more "offensive" version of 20/0. I believe they are not unique in the sense that they both derived from the same basic template of 20/0 and use artillery to replace infantry to increase some soft attack with the core concept being making 40 combat width.

And I do not think it's silly to suggest that "infantry is always with artillery and the tanks are with mobile infantry."
To all fairness, mainstream MP bans mixing tank and infantry. BUT these are just to protect new players from being bullied hard. Once people explore the possibilities of combining infantry with tank and tank variants, the division templates get spicy and interesting very quickly.
 
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Once people explore the possibilities of combining infantry with tank and tank variants, the division templates get spicy and interesting very quickly.
So infantry and artillery is the same as infantry with no artillery, but tanks with motorized infantry is different from tanks with leg infantry? Your logic is... interesting.
 
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So infantry and artillery is the same as infantry with no artillery, but tanks with motorized infantry is different from tanks with leg infantry? Your logic is... interesting.
I don't think 20/0 is the same as 14/4, but I will say that 14/4 is the same as 11/6 because they are both artillery variants of 20/0. Tank with motorized infantry is a different tank from leg infantry due to speed and cost implications.
 
I don't think 20/0 is the same as 14/4, but I will say that 14/4 is the same as 11/6 because they are both artillery variants of 20/0.
just like 14/4 is a more "offensive" version of 20/0. I believe they are not unique in the sense that they both derived from the same basic template of 20/0 and use artillery to replace infantry
Interesting...
Tank with motorized infantry is a different tank from leg infantry due to speed and cost implications.
I agree completely. However artillery vs non-artillery infantry have very different functions and costs and yet you see no difference. To me it seems you were just disagreeing with my assertation that there's ~20 unique division types which are "meta" for the sake of it.
 
You mention "reinforce width", but I cannot find any mention of this term in the hoi4 paradoxwiki. Can you please explain what effect "reinforce width" has on the mechanics of reinforcement?
The current combat width is 80, with 40 reinforce. My understanding is if you're fighting in province X, you can take up 80 width from there, and, for example, if you come from 2 other directions/provinces in addition for the same combat, you can bring in 40 width additional each to 'reinforce'.

As said, this is my understanding. One of the changes is that in some terrains, instead of half reinforce, it's only one third of the original value.
 
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Probably better to substitute the term "flanking" for reinforce, to avoid confusion with reinforcements within the battle.
 
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AT must be researched to advance TANK weaponry. You got the better guns for your tanks now - why not use some with a few INF divs? "Something" is better than "nothing"
The only issue with AT is that you can't boost penetration with XP, so it can fall behind tanks in that area. It's still the most cost effective source for hard attack though.
 
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with the meta, you know the armor value of the '40' armored div because everything is fixed

With the new system, the actual amount of armor that you will be facining is unknown. There should be much more room to build-up AT to be effective.

the "60 armor vs. 59 piercing" isn't necessarily an example that will be common. As well, being below the piercing threshold is exactly how that's supposed to work, which is why WWII saw such massive increases in armor 'inflation'