How to build thearters/forts

[Zachary]

So ive been playing this new game and loving so far, the only thing I can't find out is how to build forts/thearters, and what is the thearter's purpose? I made AI control production and it instanly started building forts/naval forts. How can I do this myself?

[Jiub]

Forts need to be built in a province. Just click on any province and look to the bottom left, there should the an icon for land and coastal forts.

Theatres are created the same way you would create a Corps HQ or Army HQ, just go up the chain of command. Though in vanilla HOI3 you can't create new theatres, you need the expansions.

Theatres do a bunch of things like provide bonuses to anyone under their command.

If you're using AI control, then the AI will mostly only operate within the provinces you've assigned to the theatre they are in. So if some rebels spawn in France or something, the AI wont pull a tonne of divisions from the Russian front to crush the rebellion.