Call of Duty is a first-person shooter video game based on id Tech 3, and was released on October 29, 2003. The game was developed by Infinity Ward and published by Activision. The game simulates the infantry and combined arms warfare of World War II.

World War II (abbreviated WWII, also referred to as the Second World War) is a conflict in which many Call of Duty games focus on including the first three games in the series, Call of Duty: World at War, Call of Duty: WWII, and Call of Duty: Vanguard.