- Dummied Out:
- One of the many things left unused is the "Alien Reproduction" item and research line in UFO Defense — strange considering the resultant Half-Human Hybrids wind up playing a key part in Apocalypse. The sequels also include other things that were ultimately left out due to time and budget constraints.
- Apocalypse also contains Procreation Parks, buildings in Megaprimus where couples go to have their children grown in artificial wombs, matching the dummied out research text of the above: "The process could be easily adapted for human reproduction".
- Franchise Killer: X-COM: Apocalypse. MicroProse later produced X-COM Interceptor, a space strategy and sim hybrid, but it was generally panned by critics. They ditched the retro-style art, and replaced it with even worse art. X-COM Enforcer is pretty universally considered the nadir of the franchise, as it ditches the strategy element entirely in favour of a So Okay, It's Average shooter, after which there were no new entries in the series for eleven years. It's pretty much considered that Hasbro did this intentionally (See Screwed by the Network below).
- God Does Not Own This World: X-COM: Terror from the Deep, Interceptor and Enforcer were primarily the handiwork of MicroProse executives, rather than the core X-COM team who wanted to pursue Alliance and Genesis instead (see below). But were forced to develop these sub-par games to placate their overlords.
- Referenced by...:
- NASA named one of their projects after XCOM (theirs is X-Ray Communications, not eXtraterrestrial Combat). They even use a branch-appropriate green patch with the motto "Communico Confido◊."
- The Necroa Virus DLC from Plague Inc. has a paramilitary group dedicated to fighting the ongoing Zombie Apocalypse that goes by the name "Z-Com" (presumably short for "Zombie Combat."
- Screwed by the Network: It was an open secret that Interceptor and (especially) Enforcer were self-sabotage on Hasbro's part, having bought up MicroProse simply to eliminate competition and intentionally running the acquired IP into the ground rather than shift resources away from Hasbro's core works.
- What Could Have Been: A few cancelled games.
- X-COM Alliance, a squad-based FPS where a team of X-COM soldiers got teleported away to another world, where they have to work together with friendly aliens to survive against hostile ones. An unfinished build of the game was discovered in late 2011.
- X-COM Genesis would have reverted to the gameplay of UFO Defense.
- Dreamland Chronicles, Gollop's Spiritual Successor to X-COM which, according to Word of God, would have similar gameplay to Valkyria Chronicles, it would be bought by ALTAR Interactive, who found the game unsalvagable and would make ''UFO: Aftermath' with it's concepts.
- The original vision for The Bureau. See its Trivia page for details.
- There were plans for a game during the classic continuity involving X-COM having lost the war and acting as La Résistance, a concept that would eventually be used for XCOM 2.
- Wiki Rule: UFOpaedia, and the Wikia XCOM Wiki (which focuses on the rebooted universe).
Trivia / X-COM