ArmA 3 is a continuation of the series of military-tactical simulator with a first-person view. Europe, scorched by the war between NATO and Iran, is practically defeated. In an attempt to escape, the NATO command launches Operation Magnitude, and sends a special forces detachment, commanded by Captain Scott Miller, to carry it out. During the first mission, "something" goes wrong and the entire squad is destroyed by Iranian defense forces. The only survivor, Scott Miller, will have to single-handedly complete the objectives of Operation Magnitude and save Europe from the invaders.