The First World War Mod: Factory Balancing
The current plan for the World War 1 mod is to set up a little diorama for testing - a game of Germany, France, and maybe Belgium/Luxembourg, fully established with the resources they had available for the western front. This will allow me to start running playtests of the general combat of the game (how it feels on my unique terrain, if railroads/urban strongholds are important, etc.) as well as start considering important unit-balancing questions such as:
How much manpower should one unit have in the mod?
How will I recreate the conditions of western-front trench warfare?
Before all of this, I need to start laying out the basic production ability of each country. i.e. how many factories should Germany and France have?
Factory Spreadsheets
For the unfamiliar, Hearts of Iron IV has three types of factories: Civilian, Military, and Naval.
Civilian factories build the other kind of factories, plus other buildings in the game - plus, a variable slice of them go towards ‘civilian goods’ depending on your current mobilisation law. This is the exponential backbone of the game’s economy - more Civilian factories means more ability to expand and start snowballing, but if you focus too hard on your passive economy you’ll be vulnerable for a rush; a pretty classic strategy game dilemma.
Military factories are what makes the actual guns, planes, and tanks that populate your units and fight the war.
Dockyards are for making ships. I can mostly ignore them for now: the main concern is Civilian and Military factories.
The quantity of factories with which major countries in the game start off is a really crucial balancing value. It needs to reflect the actual industrial balance that was present in the first world war - that is, the Great Powers need to be roughly equally matched, so as to bring on a gruelling war that might last 5 years or so. If Germany starts off too beefy, it’ll be able to take Paris with ease and then quickly finish off Russia (as was the German plan in reality). If France starts out too beefy, it might have the strength to immediately push into the Ruhr (where many of Germany’s factories will be located), and start eating away at the Central Powers’ production from day-1, leading to a boring war with very little back-and-forth.
The critical question here is this: how many troops do I want France and Germany to have by 1914? To determine this, I decided to do some modelling in Excel.
In this spreadsheet, space has been set out for the various values relating to a particular country in each year leading up to the war (the mod will begin in 1911, similar to how vanilla HoI starts off in 1936 - 3 years before the historic war). I’ve left three columns per year - one for each type of factory (again, I haven’t bothered with Dockyards yet), while general values that don’t relate to a specific factory type are just kept in the first column (bonuses to construction speed, efficiency, etc - little bonuses which are always getting increased in the game through the use of technologies and political decisions).
At the bottom of each factory column (circled in red) is how many production points that type of factory outputs in the year, given the number of factories, and any relevant bonuses. The build ratio (purple) tells the model how much focus the player will put towards each type of building each year - in earlier years, this will mostly be towards Civilian factories, and in later years construction shifts towards Military. The added number of factories in a year (blue) gives us the new quantity available for next year (green).
Then, I ran through a game of both vanilla HoI, and of my mod in its WIP state, taking notes of various values such as construction speed bonus, number of troops, etc, for Germany and France every in-game-year.
These numbers give me something to compare my model to, to make sure I haven’t made any huge mistakes. They also gave me a reality check on what scale the vanilla game operates at in terms of unit and building quantity, which I’d generally want to abide by (since, if it isn’t broken, why fix it?).
Plugging in the numbers I saw for vanilla Germany, I get a factory count that looks like this:
The results roughly line up with what I saw in-game, which means I can rest-assured tht my model predicts the behaviour of HoI pretty well. The graph also makes sense: Civilian factories are ramped up before the war, and when the war arrives production shifts over to Military factories (which unlike Civilian factories, do not increase logarithmically, since you can’t use Military factories to make more Military factories). That large jump in Civilian factories in 1913, also, represents the annexation of Austria and the Sudetenland in 1938 - an important buff-event which I was also careful to take note of.
So that gives us a good sense of factory quantities and how they’ll scale (though only a few playtests will tell if the results are actually as I intended), but the question now is how many troops will each country end up with?
Troop Quantities
Modelling army growth, as opposed to factory growth, is a more tricky subject, for the following reasons:
You can build different types of units in Hearts of Iron. Some - like infantry - are cheap, while tanks and artillery are more expensive.
Production points also go towards aircraft.
It takes time to train units and deploy them, even after you’ve made the equipment for them to use.
When the war comes, units will take attrition from the fighting: equipment will break and need replacing. This prevents armies in Hearts of Iron from scaling exponentially after an initial bump in factory creation, and generally keeps army size pretty steady after the outbreak of a war.
Since this is a first pass, I’ll be ignoring some of these facts. But in any case, the first question is how expensive is a unit, in terms of equipment?
In another spreadsheet, I wrote out the production costs of some of the main types of equipments in the game (guns, ‘support equipment’, artillery, etc.). Then, I defined how many of a given equipment goes into a type of battalion. Battalions are the building-blocks of divisions (the actual units that go onto the map and do the fighting) - this is all part of the game’s battalion-designer feature.
Although the player can design a unit with all sorts of crazy battalions, a typical meta tends to shine through in HoI: most infantry divisions settle at 9 infantry battalions, plus a support battalion of some kind (usually engineers) as the basic early-game unit. Units may become more complex (and expensive) later in the war. It’s this 9-Inf 1-Supp division I’ve used to describe the Infantry Div in the sheet, the production cost of which can be seen circled in red.
Note, also, that there are multiple tiers of this unit. This refers to the technology tiers in the game’s research system: basic guns, advanced guns, modern guns, etc. This is a big deal, because more advanced weapons tend to be more expensive to produce. And, again, I’ve really simplified the situation in this model since different techs can advance at different speeds (you can have tier-2 guns and tier-1 tanks in your division). But the bottom line is that, typically, an early-game infantry unit will cost about 500 production points to make.
So how many can we make in a year? Referring back to my factory model, I can use the annual military production, combined with a supposed build-ratio for some of the typical division designs, to do the same thing I did with the factories themselves. The result is this:
What this graph demonstrates is actually a little alarming. It seems to indicate that, by late-game, a country of Germany’s vanilla size might have around 750 (mostly infantry) divisions. This is far too many divisions, and would really cause the game to lag.
Granted, a country at war will be taking a lot of attrition, plus facing damaged infrastructure and factories. Even by 1914, however, our hypothetical country has increased its army size to over 200 (my vanilla notes show that Germany, which usually has a very large army by 1936, should have less than 100 divisions at this stage). I found this very suspicious, and ran through a test in the game to make sure that my modelling was correct: and it was, if I built mostly infantry divisions. In vanilla Hearts of Iron IV, you’ll be building a lot of tanks and planes, too, and these can take a huge amount of your factory throughput while only resulting in a small quantity of units.
So this experiment has actually given me an initial, and important, balancing pointer: since my mod won’t involve many tanks and planes early-game, I need to somehow scale up the cost of building infantry at this stage in the game, unless I want Germany and France to have a swarm of units by 1914. There are several values I could tweak for this: infantry equipment cost, factory output, predicted bonuses in each year. Luckily, with the model I’ve built, making these changes is instant. This, for example, is the result of decreasing the base factory output value:
In this case I increased it from 4.5 to 1, however, which seems far too drastic. So obviously I’ll have to keep thinking about this.
The Bottom Line
The point of this exercise has been to make an initial foray into the balancing-process of the mod. In doing so, I’ve created an increasingly elaborate (but well-documented) spreadsheet that, with various input-cells, spits out a prediction of how a typical game might go and whether or not my initial balance values are in the right neighborhood. Predictive game design is never entirely accurate: it’s a starting point, and a technique for continued tweaking.
