History VideoGame / XCom

** ''UFO Defense'' gives us the Reapers and Sectopods, the former a glorified alien attack dog and the latter a heavy assault mecha. Terror from the Deep has the Xarquid, a giant nautilus, the Triscene, a [[EverythingsBetterWithDinosaurs dinosaur with Sonic Cannons]], and the Hallucinoid, a prehistoric jellyfish with [[AnIcePerson chemical freezing agents]].

** ''VideoGame/XComInterceptor'' (1998), a spaceship fighter-themed GaidenGame that is a {{interquel}} between ''Terror from the Deep'' and ''Apocalypse''. By the year 2066, [[UsedFuture the Earth's resources are pretty much depleted]], and humanity seeks a new home with better resources. With the player as the commander of X-COM's space station, they find that the aliens from the first game aren't quite done with humanity just yet, and it falls to you to keep humanity's fledgling space colonies safe with their star fighters and combat bases.

** ''Chimera Squad'' plays it both ways: The Etherials were almost universally bastards, but their SlaveMooks were as much their victims as humanity was.

** The Griffon Tank in Apocalypse: Huge, has a BFG. Awesome stats for something you can get at the start... but because of a coding decision, will be destroyed if the road under it gets damaged, no matter what its current health is. Also, it's SLOW; flying vehicles can easily avoid it.

* BlackBox: Even when research is done, there are still something that bugs the scientists, usually the autopsies of the more exotic aliens and miscellaneous tech. They sensibly ignore it rather than taking the (extra) time to figure it out. Shows up most often in the ''Terror from the Deep'', with the implication that the boxes are the alien connection to the molecular control network.

* BrainInAJar: The final opponent of ''Enemy Unknown'', later miniaturized into an enemy unit in ''TFTD''.

** The same is unfortunately true of X-Com's forces. If the highest-ranking officer is killed, the lower ranks suffer a major morale penalty. One reason why experienced players tend to leave the Commander inside or near the dropship, where he can launch Blaster Bombs at the enemy bridge (see above).

* HarmlessLuminescence: In ''VideoGame/XComEnemyUnknown'' and its sequel ''VideoGame/XCom2'', flashbangs will disorientate aliens and their allies, but [[FriendlyFireproof will do nothing to your own soldiers]].

* HoistByHisOwnPetard: This is a theme in all X-COM Games. The aliens invade with superior technology; X-COM captures and reverse-engineers that technology; ultimately X-COM adapts and uses that technology against the invaders with great effect.

** This is potentially [[DefiedTrope defied]] by the reboot games which have an 'Ironman' option which prevents you from having more than one save file, which autosaves every turn- but, being optional, it's [[SelfImposedChallenge only for if you really want to play that way]].

* SelfImposedChallenge:
** Probably the greatest fan-mod undertaking for ''UFO Defense'' is fixing a bug that locked the starting difficulty of the game at "Beginner".
** There are a bunch of challenges listed with one of the well-known editing utilities, including things like refusing to research any new tech (thus making the game technically unwinnable, but few get to such a point since it's damn difficult without) and not killing any aliens (winning is still possible since they can be stunned).
** Zero loss run: No X-COM agents lost, no civilians lost. Difficult at best, since Terror Missions ''will'' kill civilians on turn one that you can't see. Don't try to Iron Man this one.
** [[http://ufopaedia.org/index.php?title=User_talk:Arrow_Quivershaft#1_Mission_X-COM One Mission X-COM]]: It's possible to complete the game after completing only one mission: a well-executed UFO Ground Assault on a battleship can yield all the alien prisoners and raw materials needed to research Cydonia and complete the game. The difficulty is in pleasing the Funding Nations (no terror missions or alien base assaults allowed), and in keeping away from bankruptcy. The other problem is that battleships usually ''won't spawn'' for ''months''.

* TheVeryDefinitelyFinalDungeon: The various Aliens' [=HQs=]. Failing the missions results in instant gameover:

** The city of T'leth.

* LightningBruiser: Mutons and especially the Lobstermen.

* MarathonLevel: The two-parter missions.
* MarketBasedTitle: The original game was called ''UFO: Enemy Unknown''.

* VendorTrash: All those alien corpses, spare UFO/USO compoments, and ammunition? Yeah, a good deal of that gets sold off to finance the organization. Even a relatively small UFO captured intact can net nearly a million dollars depending on how much loot you hold on to. Alien corpses are often extremely convenient for research, but supply exceeds all possible demand, so selling them is a non-trivial but disturbing source of income. (A strategy guide suggests that they make for excellent sushi. And a certain fan wiki suggests that bases frequently fighting Lobstermen requisition above-average amounts of butter.) Well, they do the same to us in the first place. They deserve every bit of what the scientists and chefs do to them.

* ArmchairMilitary: The "rear commander" tactic. Since high-ranking officers contribute to the Morale level (and significantly hamper morale when they get themselves killed), it will behoove you leave them behind in the Skyranger. The officer will continue to gain EXP and receive promotions, with the rookies and squaddies stuck doing all of the legwork. Once you go into psionics they can still make themselves useful, either mind-raping aliens or (if they're too weak psychically) scanning them with the Mind Probe.

* TheVeryDefinitelyFinalDungeon: The various Aliens' [=HQs=]. Failing the missions results in instant gameover.
* VeteranUnit: The Lucky Soldiers who survived enough battles and killed enough aliens.
* TheVeryDefinitelyFinalDungeon:

* StunGuns: From Stun Rods to Stun Bombs, a variety of nonlethal arms gradually come into X-COM's possession and employ for the capture of necessary live aliens.

** The "Gollup" chamber.

The brainchild of Julian Gollop and assorted Creator/{{MicroProse}} personnel, ''X-COM'' is a European series of games created in 1993. Players are put in charge of X-COM, a planetary defense agency, and tasked with maintaining X-COM's budget and catching {{flying saucer}}s (either by storming their landing sites or shooting them down). What follows is a mix of TurnBasedTactics and [[ResourcesManagementGameplay resource management.]] Although the games have a fair amount of [[UsefulNotes/RandomNumberGenerator randomness]], the better player will tend to win.

-->--'''Napoleon Bonaparte (attr.)'''

** The logic behind this trope is eviscerated [[AllThereInTheManual in the manual]] for ''Interceptor'', which mentions that one of the first nations to step up and do something about the alien threat was Japan, forming a specialized task force for the purpose - and having to disband it after five months with no successful UFO interceptions, because a single nation simply didn't have the money or equipment to adequately deal with things.

** And ''then'' ''Chimera Squad'' plays it both ways: The Etherials were almost universally bastards, but their SlaveMooks were as much their victims as humanity was.

* AmericaSavesTheDay: Your biggest financial contributor in ''UFO/TFTD''. Geographically, it's one of the most difficult regions to defend (the most difficult being Australasia) while still keeping a radar umbrella over the other donors, separated as they are between two vast oceans. Not a good site for a starter base; keeping a close watch on it with Skyrangers until you can afford a secondary base is the best way to go.

* ArmchairMilitary: The "rear commander" tactic. Since high-ranking officers contribute to the Morale level (and significantly hamper morale when they get themselves killed), it will behoove you leave them behind in the Skyranger. The officer will continue to gain EXP and receive promotions, with the rookies and squaddies stuck doing all of the legwork. Once you go into psionics they can still make themselves useful, either mind-raping aliens or (if they're to weak psychically) scanning them with the Mind Probe.

** You can take down the largest [=UFOs=] in ''Apocalypse'' using the smallest flyer available, hoverbikes. They're practically impossible to hit with the right settings. [[StarWars Worked for the Rebels.]]

* AliensAndMonsters: Mostly aliens, but their Terror Units are often engineered (genetically or otherwise) to either capitalize on their owner's strengths (Chryssalids having weaponized the Snakemen's rapid asexual reproduction, for example) or cover their weaknesses (Sectopods distracting the enemy with conventional attacks while their Ethereal masters make with the MindRape). Except for the [[GoldfishPoopGang Silacoids and Celatids]], which (given that their counterparts, the Mutons, don't really ''have'' weaknesses) don't really do anything.

* SpiritualSuccessor: Many. The ''VideoGame/UFOAfterBlank'' trilogy to name one. But probably the truest successor is ''VideoGame/PhoenixPoint'', developed by several of the staff who created the original ''UFO Defense,'' including Julian Gollop himself.

* SpiritualSuccessor: Many. The ''VideoGame/UFOAfterBlank'' trilogy to name one.

** ''VideoGame/XComApocalypse'' (1997), a post-apocalyptic survival-themed game that is quite different to the previous two games. By the late 2080's, the Earth is in ruins and the only hopes for survival lie in [[ComicBook/JudgeDredd Judge Dredd-esque mega-cities]], such as Mega-Primus, where the game is set. X-COM is refounded when a race of mysterious [[EldritchAbomination horrors from another dimension]] begin invading, and the player is tasked with both leading the combat group and also managing their political standings, public perception, and reputation with other MegaCorps.

In 2016, Firaxis released [[VideoGame/XCOM2 a sequel]] to ''Enemy Unknown''which re-imagines X-COM as an [[LaResistance underground resistance cell]] fighting against [[VichyEarth alien occupiers]]. The 2020 spin-off ''VideoGame/XCOMChimeraSquad'' is a combination of ''Apocalypse'' (on-the-street storyline) and the 3D games (a smaller specialized squad).

In 2016, Firaxis released a sequel to ''Enemy Unknown'' which re-imagines X-COM as an [[LaResistance underground resistance cell]] fighting against [[VichyEarth alien occupiers]]. The 2020 ''Chimera Squad'' spin-off is a combination of ''Apocalypse'' (on-the-street storyline) and the 3D games (a smaller specialized squad).

!!''X-COM'' provides general examples of:

* DummiedOut:
** One of the many things left unused is the "Alien Reproduction" item and research line in ''UFO Defense'' -- strange considering the resultant [[HalfHumanHybrid 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".

** In ''Apocalypse'' if a player raids an organization without killing anybody or damaging any property, the relations aren't penalized, despite the stolen loot. Plus ''Apocalypse'' has stun grenades, ranged stunners and mind control available from the start. Many players raid Marsec for all the cool weapons not available from the start or in short supply. There are also [[PsychicBlockDefense Mind Shields]], which were DummiedOut and cannot be bought.

** ''VideoGame/XCOM2'' (2016)[[/index]]

[[folder:A-C]]

[[folder:D-G]]

[[folder:H-P]]

[[folder:R-Z]]

%%** And then DoubleSubverted in ''XCOM 2 - [[spoiler:[[HumanResources no they]] [[AMillionIsAStatistic bloody well aren't!]]]]''

* JetPack: Your troops get these during the late game (or from the start in case of ''Apocalypse''). The flight-capable aliens (except for the psychic aliens who use their powers to fly) usually have these... [[HollywoodCyborg built]] [[BodyHorror in]].

** Inverted in ''Enforcer'', where you will chew through Sectoids, Snakemen, and Chryssalids with one shot each while their feeble attempts to harm you bounce off your armored hull. [[LetsPlay It will give your]] [[ShoutOut positronic brain much amusement.]]

** And then subverted again in the reboot: [[spoiler:Turns out the Ethereals are [[WellIntentionedExtremist Well-Intentioned Extremists]]]].
** And then DoubleSubverted in ''XCOM 2 - [[spoiler:[[HumanResources no they]] [[AMillionIsAStatistic bloody well aren't!]]]]''