Doom 3 data files

Doom 3 uses a Quake-style resource set up, with the game data being stored in zip files (with the extension instead of ) themselves stored in subdirectories of the game's installation folder. The original campaign is stored in the folder, while Resurrection of Evil is stored in the  folder. Third-party mods are likewise to be installed as additional folders within the game's main directory.

Later packs override earlier packs if they have the same content.