Call of Duty: World at War is a 2008 first-person shooter video game developed by Treyarch and published by Activision for Microsoft Windows, PlayStation 3, Playstation 2, Wii, and Xbox 360. It is generally considered to be the fifth mainstream game of the Call of Duty series and returns the setting to World War II. The game is also the first title in the Black Ops story line. The game was released in North America on November 11, 2008, and in Europe on November 14, 2008. A Windows Mobile version was also made available by Glu Mobile and different storyline versions for the Nintendo DS and PlayStation 2 were also produced, but remain in the World War II setting. The game is based on an enhanced version of the Call of Duty 4: Modern Warfare game engine developed by Infinity Ward with increased development on audio and visual effects.

The narrative for the Microsoft Windows, PlayStation 3, Wii, and Xbox 360 versions focuses on the Pacific Theater and Eastern Front theaters of World War II, involving the United States, the Empire of Japan, the Soviet Union, and Nazi Germany. It is told from the perspectives of Marine Raider Private C. Miller, US Navy Petty Officer Locke and Red Army soldier Private Dimitri Petrenko, and is based on several historical battles. 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. The game also contains downloadable content called “map packs”, which can be purchased online. A new feature to the series was the addition of a cooperative mode, which supports up to two players locally and four players online.