Singleplayer

Call of Duty: United Offensive puts the player in the role Cpl. Scott Riley in the American campaign, Sgt. James Doyle in the British campaign and Pvt. Yuri Petrenko in the Russian campaign. The characters fight in famous battles in World War II such as the Battle of the Bulge, the Invasion of Sicily and the Battle of Kursk.

The player has new abilities in the gameplay such as being able to fight in a bombing mission with mounted M2 Browning machine guns, deploying light machine guns, using flamethrowers in combat, cooking grenades, and sprinting.

Cpl. Scott Riley is the first playable protagonist of United Offensive in the American campaign. Riley participates throughout the entire Bastogne campaign by defending Bois Jacques, capturing and securing the crossroads and town of Foy, and capturing Noville. Pvt. Elder, a soldier who served in Fox Company is in the first mission of the game. Elder initially goes on a patrol with Sergeant Moody and Corporal Riley and gets wounded while the three escape pursuit by German forces. Ender is never heard from again as a medic tends to his wounds; Elder is voiced by Quinton Flynn.

Sgt. Doyle is the second playable protagonist in United Offensive, serving as the playable character in the British campaign.

Pvt. Yuri Petrenko is the third playable protagonist in United Offensive. Petrenko participates in the entire Battle of Kursk by defending their trench bases, securing Ponyri, destroying German armor in Prokhorovka, and assaulting and defending Kharkov until the arrival of Soviet reinforcements. Sgt. Antonov is the player's squad leader during the Battle of Kursk.