Black Ops is a first-person shooter video game developed by Treyarch, published by Activision, and released worldwide on November 9, 2010 for the Microsoft Windows, Xbox 360, PlayStation 3, Wii, and Nintendo DS platforms. Announced on April 30, 2010, the game is the seventh installment in the Call of Duty series, and the first set during the Cold War. It is the third in the series to be developed by Treyarch, and is a direct sequel to Call of Duty: World at War.[3]

In the first 24 hours of release, the game sold over 5.6 million units, 4.2 million in the United States and 1.4 million in the United Kingdom, breaking the record set by its predecessor, Modern Warfare 2, by approximately 2.3 million copies.[4][5] On May 1, 2012, the sequel Call of Duty: Black Ops II was revealed for release in November 2012.