Call of Duty: World at War is a first-person shooter video game developed by Treyarch and published by Activision for Microsoft Windows. It is the fifth installment in the Call of Duty series, excluding expansion packs.

The game's setting returns to series' trademark World War II setting , after the previous title, Call of Duty 4: Modern Warfare was set in present day. It focuses on the Pacific Theater and Eastern Front of World War II.

The multiplayer component of the game contains various game modes and a leveling system that allows the player to unlock additional weapons and rewards as they progress, similar to Call of Duty 4. A new feature to the series is the addition of a cooperative mode, which supports up to two players locally and four players online.