Gears of War is a tactical third-person shooter video game developed by Epic Games and published by Microsoft Game Studios. It was initially released an as exclusive title for the Xbox 360 on November 12, 2006 in North America, and on November 17, 2006 in Europe (excluding Germany, where Microsoft Game Studios did not publish the game after it was denied a rating). A Limited Collector’s Edition was also released, which included a disc of bonus content and an art book titled Destroyed Beauty that detailed much of the game’s back-story. A Microsoft Windows version of the game was created with additional content and released in North America on November 6, 2007, ^{with a Mac OS X version also confirmed.}

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. The game is based on the use of cover and strategic fire for the player to advance through the scenarios; a second player can play co-operatively through the main campaign to assist. The game also features several online game modes for up to eight players.

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, and was the second-most played game over Xbox Live during 2007. A film adaptation is currently in the works. The first sequel, Gears of War 2, was announced on February 20, 2008 and is currently slated to be published in November of the same year.