ARMA 3 is set in the near-future, during the mid-2030s, where NATO forces deployed in the Greek islands of the Aegean Sea are trying to hold off a massive Iranian military offensive from the east. During the singleplayer campaign, the player will take the role of a British Special Forces soldier, Captain Scott Miller. Initially, the player must survive on their own after friendly forces are defeated in a failed NATO operation. During the campaign, the player will face everything from lone wolf infiltration missions to the commanding of large scale armored operations. The player will be able to choose different objectives and weaponry (such as UAVs, artillery, and air support) according to their play style.
ARMA 3 takes place on the Aegean islands of Altis (formerly Lemnos) and Stratis of Greece, in the Mediterranean Sea. They will feature photo-realistic terrain and water environments. Altis will be the largest official terrain in the Arma series with ground area covering approximately 270 km². The smaller island, Stratis, will expand over an area of 20 km². The islands will feature over 50 villages with buildings that are both enterable and destroyable.