Call of Duty: Vietnam is a cancelled installment of the Call of Duty series that was under development by Sledgehammer Games. It was stated to be taking place in the 1960s and 1970s, in Cambodia, Vietnam and Laos.
The game was planned to be in the action/adventure genre and would've been the first third-person only Call of Duty game. After eight months of development, the game had up to 15 minutes playable, at which point Activision offered Sledgehammer the opportunity to help Infinity Ward in the development of Call of Duty: Modern Warfare 3.