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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 not that hard to post a survey so players can actually decide what they want to get fixed instead of you making the game even more convoluted (by fixing what you think is broken instead of what actually ruins the game) than it was 2 seconds ago
No need. If you read any of the hundreds of combat width discussion threads over the years you will see that the two most popular changes are:
* more varied width + less overstack penalties so that it matters less what width you use and if it aligns perfectly
* have targeting and damage allocation not be so advantageous for wide divisions
 
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Let's break the meta! I hardly understand it anyway!

I personally love the idea that we're busting open the old strats and assumptions about optimization. It demands innovation.

I hardly understood anything in this diary, since I much prefer playing the actually game and not crunching every number possible, so I suppose I am thrilled! I feel liberated I get to tackle a new system that encourages taking new risks and breaking away from the tried and true 10/20/40w
 
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Hi Podcat,
since you are Game Lead i would like to copy one last time a heavily upvoted post from past diarys with an easy to implement suggestion.

I have a suggestion for all focus trees.
Please mark the "historical" path in the focus tree somehow, so that as a player i can jump in as any nation and when i open the focus tree, i can see what focuses to take in what order for a historical game. I think the best way to do this would be to just highlight the focuses taken by the AI in historical mode and the order they are taken in.

 
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How do cities provide a greater combat width than flat fields?

Restricted fields of fire and the difficulties in defending a sector/massing firepower that come from that. In open country a battalion might attack on a frontage of 500m, or defend two or three km with a very thin line based on strongpoints connected by roving patrols. In places like Stalingrad and Arnhem, battalions attacked on the frontage of a single street.

Aren't those just different magic numbers, then? I've never really heard a case made for why historical divisions were optimal

A good commander always assembles a reserve and holds on to it until the critical moment. In the old style "square" units with four maneuver elements that were common prewar, the commander had the choice of either having a very paltry reserve of only a quarter of his strength, or leaving fully half of his command out of the battle. Neither was ideal. He was also highly overworked, with four subordinates competing for his attention. A "triangular" organization, where there are three squads in a platoon, three platoons in a company, three companies plus a heavy weapons company in a battalion, and so on, became almost the international standard during the war. It was found to be the most flexible, in terms of giving the commander a "two up-one back" organization for either attack or defense. Also, by keeping the number of subordinates each higher commander had to supervise low, it kept the command bandwidth flowing.

So yes, there are historical and operational reasons why certain unit sizes and compositions were preferred. It wasn't just a question of economics and manpower.

I'm very lost on what the benefit of these combat width changes is. No country is made up of one terrain type, there's forests, mountains, plains, cities, and so on, so it seems like the options are either:

-Make very specialized division for every terrain type and constantly micro the frontlines for optimum efficiency at the cost of colossal amounts of clicking (and slowing down offensives)
-Just make something that seems 'good enough' and spam it, and eat the minor inefficiencies
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.
 
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I have a suggestion for all focus trees.
Please mark the "historical" path in the focus tree somehow, so that as a player i can jump in as any nation and when i open the focus tree, i can see what focuses to take in what order for a historical game. I think the best way to do this would be to just highlight the focuses taken by the AI in historical mode and the order they are taken in.
its something thats on my list to do, but I am not sure when yet.

What about gainable traits for generals that reference unit types? Is the whole concept of dominant type gone or just for the high command bonuses?
yeah its everything about dominant type

Am i right to assume that the 60% Infantry Division gets 60% of the buff so that a 15% attack buff from the guy you put in your goverment effectly becomes a 9% attack buff for that Division? Or did I understand that wrong?
yes pretty much

Some decent under the hood changes, though I will echo the sentiment that armour vs. piercing still seems too binary when the former is higher than the latter.
you'd expect something like extra damage for over-piercing right? The reason its like this is so anti tank weapons dont just become fantastic infantry killers basically. I've played with ideas for allocating strikes by hardness but as i said I am not ready to dig into the targeting changes yet because I havent tested or implemented them so I am not sure exactly how it will end up outside of the width spreading of damage needing to be dealt with.
 
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I don't really get the changes to high command bonuses either. Why don't they just apply on the battalion level?
The idea is that they function more like combined arms (or like hoi3 if you know how it was there). So the whole is greater than the sum of its parts so to speak. So the idea is that the division as a whole performs better because its backed up by artillery rather than just the artillery
 
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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!
100% true, but in a game with a global map, with divisions as the basic unit, certain abstractions are made. Independent regiment/brigade/Kampfgruppe action was absolutely commonplace but it'd be rare for a unit detached thus to get farther away from its parent division than width of an in-game province. In general we should consider detached actions to be subsumed components of the generalized province-wide battle.

I'm the sort who translates dusty old photocopies of TOEs for units that have been whispers and dust for almost a century, so believe me, I know the small stuff is mega important too. Just, we can't granularly depict absolutely everything, or the game would be figuratively unplayable.
 
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Hi, i have two questions:

1. Is there something to make spamming 2-width divisions and/or underequipped divisions for defence unviable? Somebody correct me please if this is already the case but that's how i understand the combat mechanics at the moment.
there is a stacking penalty that kicks in on many small divisions which was added in the past when we had issues with 10w meta

@podcat Are these changes going to be applied exclusively for DLC owners or is this changing for everyone regardless of DLC and game version?
its part of the free patch
 
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Yeah, because countries picked the number of battalions in their divisions by terrain... *facepalm*
Ummm except they did often times? An example of the Wehrmacht having specialized divisions for different terain:

Nazi Germany also organized "Jäger divisions" to operate in more adverse terrain.
 
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How is the AI at handling these changes, and will we ever see a dev diary on that?
 
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Then why even change this aspect of the combat system if not to force players to use specialised divisions (which really only specialise in combat width). If I attack reinforcing isn't a huge concern anyway. If I click with 4 tank divisions and 2 of them get de-orged causing the whole stack to stop the attack, I just select the remaining 2 and click again. It only matters for defense. So I guess a Soviet player will now do 30 w for all plains and a different combat width for all other terrain types because he got time to set it up.
I guarantee you know more about the minute, micro details of HOI4 mechanics than me :D I'm just offering some perspective as a history nerd.
 
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I feel like comparing Jungle to forest is a bit underwhelming. Maybe make Jungle comparable to Marsh?
I don't know... i just feel like vietnam has taught us that forest =/= Jungle, but I guess I'm nitpicking again
This discounts combat modifiers for jungles which will still be far harsher
 
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Will you scale the High Command bonuses after depending on type? Most divisions won't have much line artillery, so a bonus to just one or two BNs won't matter much compared to a bonus for infantry.

And how about support artillery? Will they benefit from an artillery bonus?
support doesnt add to it, but would technically benefit if there is line infantry. As for balancing a lot of these didnt kick in at all before so we'll likely need to do some balancing on a few of them

I love these changes, but I disagree with some of the width choices, I feel like jungles should have a smaller width since they are so dense and very difficult to maneuver through. I would almost argue that they should be smaller than mountains, but I also feel mountains should be broken up into forested and rocky mountains since that has a huge impact on what sort of maneuver corridors are available to a military force. I like the idea behind smaller reinforcement rates for these areas as well.
Dont forget that there are other factors like combat modifiers also at play. where jungles are super horrible to operate in as is (especially with the new supply flow.)
 
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