Paradox Interactive is preparing a third expansion for Hearts of Iron III. The popular grand strategy game, a genre the publisher is known for, will release the add-on Their Finest Hour on September 26, 2012 on PC. The company released the first developer diary explaining some new additions.

Alongside new units and things like that, Their Finest Hour will also allow people to create customized games. Anything from diplomacy points to research can be adjusted for individual countries, which is done to cater to gamers that enjoy a sandbox experience. More so, this element will enable mods for the community to work on.

A second addition is the mapping possibilities that come with the expansion. Players can use these to plan attacks, map out schemes and strategies that will help them win the war. This can further be implemented in the game’s multiplayer, by sending your schemes over to friends in order to coordinate attacks.