H.A.W.X. includes over 50 planes available for aerial warfare. It is set in 2012 in a world increasingly dependent on private military companies (PMCs). As these non-governmental organizations gain power, global conflict erupts with one powerful PMC attacking the United States. The game is set in the same universe as Tom Clancy's Ghost Recon: Advanced Warfighter, as Scott Mitchell is shown calling for air support from a H.A.W.X. pilot in the trailer. The game features an Enhanced Reality System (ERS), which can include radars, incoming missile detection, an anti-crash system, damage control system, tactical map, information relay, weapons trajectory control and the ability to give commands to an AI squadron. When fully activated, ERS provides assistance to the player. Some or all of these assists can be turned off to make the game more difficult. H.A.W.X. supports four-player co-op throughout the campaign. Players can join other players games on-the-fly. There is also a versus mode where up to 16 players can battle online for experience points and in-game cash, to unlock new weapons.