Army of Two is a co-op third-person shooter with a major focus on cooperative and coordinated strategies. Players can join up with either the game's built-in Partner Artificial Intelligence or other players. Army of Two has been designed to necessitate teamwork as some missions may be close to impossible to complete without using the cooperation element. The game allows a great deal of weapon customization. Some guns available for customization include: pistols, shotguns, submachine guns, rocket launchers, light machine guns, sniper rifles, grenade launchers and assault rifles. Such elements as stocks, under-slung grenade launchers, suppressors, grip handles, extra-large magazines and new barrels, can be swapped out to give the weapon a unique look.