Call of Duty is a first-person and third-person shooter video game series franchise. The series began on the PC, and later expanded to consoles and handhelds. Several spin-off games have also been released. The earlier games in the series are set primarily in World War II; starting with Modern Warfare, set in modern times, the series has shifted focus away from World War II. Modern Warfare was followed by Modern Warfare 2, set in modern times, and Black Ops, set during the Cold War. Modern Warfare 3, also set in modern times (as the name suggests) was released on 8 November 2011.

As of November 27, 2009, Call Of Duty games had sold 55 million copies for $3 billion in revenue.

As of February 9, 2012 there are 40 million monthly active players across all of the Call of Duty titles, with 7 million Call of Duty: Elite users and 1.5 million paying annual members.