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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.

Screenshot_1.png


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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I think all these changes are good, but I'm still not sure why the current combat width system is better than the historical designer of previous games (this isn't nostalgia, HOI4 was my first HOI game). A historical, for example German, division design would be 9 infantry battalions, 4 artillery battalions (3 light + 1 heavy), 1 AT battalion, and the rest being what are in-game support battalions. That's a combat width of 31, which exactly fits no terrain and is a compromise between plains and cities. Cities are one of the places you'll be fighting least no matter your local terrain, so you'd think it would be better to compromise between something like plains and forest (for Russia) and take out one of those artillery battalions (I guess you could look at the heavy battalion as a support company?). Realistically I'd imagine the meta would be no artillery and mix infantry with AT instead of basing it off the historical one anyway. Or stay at 20 width if you're not expecting to fight on plains since most of those terrains are pretty close to 80. It's better than before but it's still pretty ahistorical, which I don't think is a huge issue, and more complex and hard for new players- which is. In general the overfill penalty being what it is puts a lot of constraints on division design.

Good updates though, definitely an improvement, I just complain a lot ;).
You are right about historical German infantry divisions (before 1944) except for artillery. They (mostly/often, not always) did have 4 artillery battalions as you said, but with a total of 48 field guns and howithers, plus infantry guns and mortars in the infantry regiments' and/or battalions heavy companies/batteries. In game an artillery "battalion" has 36 guns, so 4 "battalions" makes total of 144 guns. Historically 36 field guns/howitzers was (and still is) called an artillery regiment. I have read thru all historical division templates I have found online, and the highest number of artillery weapons, field artillery plus heavy (15cm) infantry guns and heavy (12cm) mortars in a German infantry division was 90, and that was for 1944 Volsgrenadier Division that had only 6 infantry battalions, but higher allocation of heavy weapons. Even if you think a division would be allocated a corps artillery battalion (of 12 guns), we get 102 at max, and that reinforcement would be temporary. A more realistic number, taking into account arty, IG and mortars, would be 2 "battalions" of 36 guns, plus (possibly) the 12 gun support arty battalion. This was about Germany, but I also don't know of any other nation having divisions with 100+ artillery, except when temporarity reinforced with corps and army artillery.

That being said, I am very happy to hear about these planned changes to the game. I want HOI IV to be "historical" but with a lot of "what if's", not just like any other game, where game mechanics dictate all the choices to optimize results. I highly applaud changes that will make the game more playable with triangular divisions. 40 width "meta" is totally unhistorical: too wide for a historical division, too narrow for a historical corps.
 
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You are right about historical German infantry divisions (before 1944) except for artillery. They (mostly/often, not always) did have 4 artillery battalions as you said, but with a total of 48 field guns and howithers, plus infantry guns and mortars in the infantry regiments' and/or battalions heavy companies/batteries. In game an artillery "battalion" has 36 guns, so 4 "battalions" makes total of 144 guns. Historically 36 field guns/howitzers was (and still is) called an artillery regiment. I have read thru all historical division templates I have found online, and the highest number of artillery weapons, field artillery plus heavy (15cm) infantry guns and heavy (12cm) mortars in a German infantry division was 90, and that was for 1944 Volsgrenadier Division that had only 6 infantry battalions, but higher allocation of heavy weapons. Even if you think a division would be allocated a corps artillery battalion (of 12 guns), we get 102 at max, and that reinforcement would be temporary. A more realistic number, taking into account arty, IG and mortars, would be 2 "battalions" of 36 guns, plus (possibly) the 12 gun support arty battalion. This was about Germany, but I also don't know of any other nation having divisions with 100+ artillery, except when temporarity reinforced with corps and army artillery.

That being said, I am very happy to hear about these planned changes to the game. I want HOI IV to be "historical" but with a lot of "what if's", not just like any other game, where game mechanics dictate all the choices to optimize results. I highly applaud changes that will make the game more playable with triangular divisions. 40 width "meta" is totally unhistorical: too wide for a historical division, too narrow for a historical corps.
I firmly believe that the 36 guns/battalion design is to reduce the effects of attrition. The designation and manpower point towards a battalion. The firepower is also about what you would expect to see from a battalion.
 
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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.
Isn't this what happened with Tinto?
 
First of all, I love the changes. Well done ! I am very happy with the proposed changes.
Also, my +1 one for this suggestion below. I find myself sometimes just as lost on what happened in real life.

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.
[/QUOTE]
 
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First of all, I love the changes. Well done ! I am very happy with the proposed changes.
Also, my +1 one for this suggestion below. I find myself sometimes just as lost on what happened in real life.
Agree. This would be so helpful.
 
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For you nothing change, if you let do the Admirals and Generals etc. the work. Set only the Zone wehre they have to fight and the attack / defense Thing.

you have only to watch how you equip your troops. Don’t forget the Helper-Troops.
 
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

And what about making line artillery useful? The meta is that it is a noob trap, and people shouldn't use line art, but historically it was very important specially in the American doctrine (which in game ironically buffs non-artillery battalions the most).

I think artillery should be limited to the bottom row and would only be possible to add 1 per regiment, and only if you have at least 3 battalions already. But it would have 0 width and fire mixed into the frontline battalions or indirectly from behind.
 
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And what about making line artillery useful? The meta is that it is a noob trap, and people shouldn't use line art, but historically it was very important specially in the American doctrine (which in game ironically buffs non-artillery battalions the most).

I think artillery should be limited to the bottom row and would only be possible to add 1 per regiment, and only if you have at least 3 battalions already. But it would have 0 width and fire mixed into the frontline battalions or indirectly from behind.
That would remove choise as it would be a must to have exactly as many artillery as you can have.
 
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Honestly this looks good. Focusing and improving mechanics like these in my opinion is far more important than making focus trees, since focus trees from DLCs will only exist in the vanilla game, but base mechanics affect every single mod out there. Stat changes like this were long needed and very useful, so great job on that.
 
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@Jamor, you seem to know about TO&Es, and real life battalion, Squadron set up. Why does HOI4 have Artillery add to the width? The closest battery to the battle is going to be 1500 to 2000 meters behind the FEBA and more likely to be at least 4 Km back, so why would they add to the width?
 
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Why does HOI4 have Artillery add to the width?
They are trying to restrict the number of artillery units in a division. Same reasoning artillery units have zero (0) ORG.

Width is an abstraction for many things, not just combat frontage.
 
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That would remove choise as it would be a must to have exactly as many artillery as you can have.

You would put as many as you can afford. Exactly like in real life: Rich UK and USA? The most artillery. Other majors: a little less. Japan and bigger minors: Significantly less.... Rest: No artillery


Why being realistic is bad? Right now there is also no choice for Meta players, no one uses line art!

And how do you explain everyone in ww2 using line artillery in all infantry divisions in similar amounts? All stupid?
 
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@Shaka of Carthage, I am sure you mean well. I am sure you are correct. I want to hear from the devs their reasoning.

If you go read the pre-release dev diaries I'm sure one of them replied in those. It's been a long time but IIRC the argument was that width was for the whole PROVINCE and artillery parks, with all their ammunition & supplies took up a large area and blocked the movement and traffic of other units in the area.

But mostly it was just a game justification to stop people stacking 80 divisions of 1 inf, 24 artillery in every square.
 
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To re-state an old suggestion of mine (from an older post), I hope they add sectors. Tl;dr version: flesh out the garrison order with a few more rules and the ability to have a Stance for your army.

In addition to being able to draw up offensive arrows and fallback lines for your armies, you'd be able to draw up sectors for them to operate in. Each sector could be within friendly and/or enemy territory. You would then set a stance for the army, which could for example have five steps, from Aggressive Assault through Hold in Place to Full Retreat, which would tell the army in the sector what it would actually do.

Also, the same way you can set objectives to prioritize with the Garrison order, armies assigned to Sector order would be able to prioritize air fields, factories, VPs, and so on, and keep them in mind when attacking, not just defending. For example, if you tell the army to prioritize airfields, they will do what they can to capture enemy-held airfields, while also defending the ones in friendly provinces.

Definining actual sectors would also allow players to set rules like "no other armies' divisions allowed in this sector", or "no foreign divisions allowed". Also, you could have a separate button telling the game how far, if any, you can exceed the supply limit of the sector.

This is very close to how the Garrison order and aggression level setting in the BP (that button you can set to >, >>, or >>>) work already, just with a few more features, so it shouldn't be too much work to implement :) . Come to think of it, you could merge the two by having "Garrison" be another stance for Armies and assigned to sectors.
 
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I'm not sure it's gonna work. You can't really effectively "compact" a division in urban environment - there is not enough place for that. If you do that, you make it a perfect target, which also can't direct their own fire effectively. Effective urban combat assume splitting the big formation, not concentrating it.
So, until devs indeed going to represent per-battalion fighting (which I suppose they would not), I'd say lower width and higher width reinforcement (as, indeed, there are a lot of approaches to city, which can be used by attackers and defenders both) warranted better.
Urban environments suck in the combat units, especially in WW2 where small unit commands were given verbally. If you can envision an infantry division as a rectangle while defending in plains, try to imagine the rectangle becoming a triangle once it enters an urban environment. You are right, there is a lot of people and equipment in a division that cannot fit in that narrow space, but those guys are not front line fighters. Those rear guys lob shells, move stuff, and spread out in the back. The fighters are in a much much smaller space up front. Why? Their direct fire weapons have almost no line of sight reducing firing ranges to hundreds of feet to the front or the rear, but zero range to the sides. Also, mobility is from dead stop to snail's pace. An infantry division of 15,000 plus men only has about 5,000 to 6,000 fighters. When they cannot properly deploy their weapon systems, they must bunch up to have the same combat power they had in a much wider environment or the lack of mobility will see your units destroyed one by one.
 
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Definining actual sectors would also allow players to set rules like "no other armies' divisions allowed in this sector", or "no foreign divisions allowed". Also, you could have a separate button telling the game how far, if any, you can exceed the supply limit of the sector.
When you say "no foreign divisions allowed" I assume you mean "allied divisions"? Banning the enemy from a sector would be cool, and all, but I'm sceptical as to their willingness to comply... ;)

Edit: you might actually add the ability to assign a sector to an ally (agreement to be accepted by the ally, but usual for the AI). Sounds like a very nice system.
 
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