ARMA 2 is a tactical shooter with significant vehicle and aircraft elements. The player is able to command AI squad members which adds a real-time tactics element to the game. This is further enhanced by introduction of the high command system, which allows the player to command multiple squads using the map. ARMA 2 is set primarily in the fictional Eastern European nation of Chernarus, (meaning "Black Russia’"). The Chernarus landscape is based heavily on the Czech Republic, the home country of the developer.
The game takes place in the eastern part of a fictional post-Soviet state called Chernarus, namely the region of South Zagoria and the remote island of ÚtesThe area of approximately 225 km² is based on actual satellite photos of České Středohoří. All necessary data is loaded silently in the background, therefore the player is at no time interrupted by any loading screens while traveling through the terrain, though there are loading screens between episodes.