To warn you all this dev diary is no way assumes that you have any idea how to mod EU3 and EU:Rome so if you are familiar with the moding of either of these two games you will get a certain amount of déjà vu.
So let’s talk about the moding of HoI3. First off we have a Mod Dir allowing you to have multiple mods installed and also be able to plan the vanilla version all at the same time. Each mod you install does not over write the vanilla files and is instead stored in its own directory structure. Obviously for those of you who skipped EU3 and EU:Rome this should be a nice little change.
Next thing the map, there are 4 map files for you to play around with. All are bitmap files allowing you to tweak things to your hearts content pretty easily. One is the province map, you can redraw, add and remove province boundaries. Note changing this will involve the game recalculating paths the first time it is used and which takes a while, so you may want to ship the new paths with your mod. Then there is the river map, if you wish to move rivers about. The third map mode it the terrain map mode, this allows you to play around with the underlying terrain of the provinces. There is also a separate file that will change the textures according to your definition and also defines what terrain does. The final map file is the master temperature map that stores the mean temperatures around the world, the angrier the red is the warmer it is. The final piece of the puzzle is the master map file in here you find interesting things like the provinces that generate pressure zones.
The next big chunk is the common folder. This folder covers a whole bunch of variables, but the one you will be most interested in is the defines file. This has over 100 separate game variables for you to play around with. The biggest chunk being the military ones. If you think the defence is too good you can play around with the dig in values, play around with the maximum level and what affect each level has. All in all we have tried to provide a serious playground for moders here. Now for those of you planning things like regiment mods there is of course a variable BRIGADES_IN_DIVISION, guess what this does?
Let’s talk about the AI, we have a number of Lua scripts. We have two types, generic and country specific. We have exported a fair amount of the high-level country functions, like technology and intelligence into Lua scripts. We have done this in the case of the foreign minister to help steer World War II. For example in the case of Germany, if it is after February 1941, France is defeated and it has no wars with land neighbours the Lua scripts instruct the strategic AI to prepare for war with the Soviet Union. The Strategic AI then does things like prioritise theatres bordering the Soviet Union for troops. When the strategic AI is happy enough war will begin. There are exceptions to this though; the Soviet AI is so cocky it doesn’t even think preparing for war is worth the effort in the case of Finland.
We of course have scriptable unit files that as in Hearts of Iron 2 you can freely tweak the values. However not only are there more values in Hearts of Iron 3 (for example you can change the amount of space a brigade type takes up in a transport ship) but you are free to add in as many extra brigade types as you like. You cannot mod the brigade core stats those are hard coded.
Of course events and decisions are in plain text and are freely modable. So you can add more, edit the ones that are there. There is Lua support for evaluation of decisions, and even for the AI to prepare to execute a decision. Allowing you to do more with decisions than you ever were able to even in EU3.
Well that gives a brief overview of the moding potential of HoI3, we hope you have fun with it.
Here's a few screenshots to talk over..