20 XCOM

XCOM is a science fiction video game franchise featuring an elite international organization tasked with countering alien invasions of Earth. The series began with the strategy video game X-COM: UFO Defense created by Julian Gollop's Mythos Games and MicroProse in 1994. The original lineup by MicroProse included six published and at least two canceled games, as well as two novels. The X-COM series, in particular its original entry, achieved a sizable cult following and has influenced many other video games; including the creation of a number of clones, spiritual successors, and unofficial remakes.

The Bureau: XCOM Declassified is a 2013 tactical third-person shooter video game. It was developed by 2K Marin and published by 2K Games. As the eighth title in the turn-based strategy series X-COM and a narrative prequel to XCOM: Enemy Unknown, the game was released for Microsoft Windows, PlayStation 3 and Xbox 360 in August 2013. Set in late 1962 at the height of the Cold War, the game's premise mainly revolves around The Bureau, the predecessor of the Extraterrestrial Combat Unit (XCOM), as they attempt to repel an alien invasion. As a tactical shooter, players can use the battle focus mode to issue commands to two other agents accompanying the protagonist, William Carter. Players can permanently lose their squad members so they must make good tactical decisions.

X-COM was part of a budget range video game series released in 1999 by Hasbro Interactive for Microsoft Windows that relied solely on the play-by-mail concept.

X-COM: Alliance is a cancelled video game in the X-COM series. The game was developed by three different teams of MicroProse developers between 1995 and 2002. The game had the player assume the role of commander of the militarized scientific mission lost in space during the aftermath of X-COM: Terror from the Deep.

X-COM: Apocalypse is a 1997 science fiction turn-based tactical strategy game. It is the third game in the X-COM video game series. It was developed by Mythos Games, and published by MicroProse in 1997 for MS-DOS and Microsoft Windows.

X-COM: Enforcer is the sixth game in the X-COM series, but takes place in a time line separate to that established by the first four games of the series. Enforcer is as a purely action third-person shooter, not containing elements of strategy game unlike the previous games. It was the last game released in the series until Firaxis Games' 2012 reboot.

X-COM: Terror from the Deep is a strategy video game developed and published by MicroProse for the PC in 1995 and for the PlayStation in 1996. It is a sequel to X-COM: UFO Defense and the second game of the X-COM series, this time taking the war against a renewed alien invasion into the Earth's oceans.

X-COM: UFO Defense is a 1994 science fiction strategy video game developed by Mythos Games and MicroProse. It was published by MicroProse for MS-DOS and Amiga computers, the Amiga CD32 console, and the PlayStation.

XCOM 2 is a 2016 turn-based tactics video game developed by Firaxis Games and published by 2K Games. It is the sequel to 2012's reboot of the series, XCOM: Enemy Unknown; it takes place 20 years after the events of Enemy Unknown. XCOM, a military organization trying to fight off an alien invasion, has lost the war and is now a resistance force against the occupation of Earth and the established totalitarian regime and military dictatorship. Gameplay is split between turn-based combat in which players command a squad of soldiers to fight enemies, and strategy elements in which players manage and control the operations of the Avenger, an alien ship that is used as a mobile base for XCOM.

XCOM 2: War of the Chosen is an expansion pack for the 2016 turn-based tactics video game XCOM 2, released for Windows on August 29, 2017. Versions for macOS and Linux were released on August 31, 2017, and a Nintendo Switch port was released on May 29, 2020.

XCOM: Chimera Squad is a turn-based tactical video game developed by Firaxis Games and published by 2K Games as part of the XCOM series. It is set as a sequel to XCOM 2: War of the Chosen, after a tenuous peace accord between warring human and alien forces has been achieved. The player controls a mixed squad of human and alien special forces soldiers that help maintain the fragile peace of City 31, an experimental city where humans and aliens are attempting cohabitation. While Chimera Squad follows similar tactical elements of the XCOM series, it introduces new gameplay concepts to accelerate the pace of gameplay.

XCOM: Enemy Unknown is a 2012 turn-based tactical video game developed by Firaxis Games and published by 2K Games. The game is a "reimagined" remake of the 1994 cult classic strategy game 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.

XCOM: Enemy Within is an expansion pack for the turn-based tactical video game XCOM: Enemy Unknown. The expansion pack primarily adds new gameplay elements to the base game, as well as introducing new themes of transhumanism via aggressive gene therapy.

X-COM: Interceptor is the fourth main game in the X-COM series, developed and published by MicroProse in 1998. The game is a combination of many genres, including space flight simulation, business simulation game and strategy game elements. More specifically, the player's role includes managing a number of X-COM space stations, piloting starfighters during hostile encounters whilst co-ordinating wingmen, and managing resources and research. X-COM Interceptor, although released as the fourth game, is actually set before X-COM: Apocalypse, thus making it the third game in the chronological order. The game was re-released in 2008 for Steam and GamersGate, and again in 2016 on GOG.com.