Gears of War is a tactical third-person shooter video game developed by Epic Games and published by Microsoft Game Studios. The game centers on the soldiers of Delta Squad as they fight to save the human inhabitants of the fictional planet Sera from a relentless subterranean enemy known as the Locust Horde. The player assumes the role of Marcus Fenix, a former prisoner and war-hardened soldier.

Gears of War has been highly successful since its release; it sold over three million copies in just ten weeks and was the fastest-selling video game of 2006.