Much of the content of GC3 is defined in editable XML files that can be changed or added to by user created mods. Mods are placed in the Documents\My Games\GalCiv3\Mods folder for the base game, or in the Documents\My Games\GC3Crusade\Mods folder for the Crusade and Intrigue expansions. An ExampleMod folder is created in the Mods folder for you the first time you run the game to show the expected folder structure of a mod.