The game is a "reimagined" remake of the 1994 cult classic strategy game UFO: Enemy Unknown (also known as X-COM: UFO Defense) and a reboot of MicroProse's 1990s X-COM series. Set in an alternative version of the year 2015, the player controls an elite multinational paramilitary organization called XCOM during an alien invasion of Earth. The player commands troops in the field in a series of turn-based tactical missions; between missions, the player directs the research and development of technologies from recovered alien technology and captured prisoners, expands XCOM's base of operations, manages finances, and monitors and responds to alien activity. Much like its predecessor, XCOM: Enemy Unknown casts the player as the commander of an elite military organization. As commander, the player directs their soldiers in turn-based combat missions against alien enemies. Between missions, the player directs the organization's research and engineering divisions in creating new technologies and improving XCOM's base of operations, and manages the organization's finances.