''X-Factor'' debuted as an ''ComicBook/XMen'' spinoff in [[TheEighties early 1986]]. Around that time, Xavier was heading into space to be with his love Lilandra, who just happened to be the Empress of the galactic Shi'ar Empire. They and the X-Men were on pretty good terms, particularly after they saved both the Empire and the Universe from the previous Shi'ar Emperor.

''And'', in addition to all that, it just so happened that SelfDemonstrating/{{Magneto}} was recently [[HeelFaceTurn trying to turn a new leaf]].[[labelnote:*]][[HeelFaceRevolvingDoor It didn't stick.]][[/labelnote]] Oh, and it ''also'' just so happened... that Jean Grey had not died a few years before. And ''finally'', Beast, Angel, and Iceman had recently joined a [[{{Retool}} brand-spankin' new version]] of ComicBook/TheDefenders. This didn't last long, and it ended with everyone except for the aforementioned three being killed off. [[UnexplainedRecovery Don't worry, they]] [[DeathisCheap got better.]] So now, those three characters were free game for ''other'' projects.

So... here's what all of this resulted in: Charles Xavier decided to go into space to be with Lilandra, and put the recently reformed Magneto in charge, in his stead. However, Cyclops had a problem with that, what with, you know... Magneto previously being the X-Men's deadly ArchEnemy and all. So, Cyclops reunited with Iceman, Angel, The Beast, and Jean Grey (notice it's the original X-Men lineup), after learning of how she was now alive again. The group dedicated themselves to continuing Charles Xavier's dream.

And if you want even ''more'' details, just go to Wiki/{{Wikipedia}}.

After they rejoined the expanded team of X-Men, the title now switched to detailing the exploits of a new, government-sanctioned team of mutants, most notable for turning CListFodder like Jamie Madrox into {{ascended extra}}s. That series was cancelled in 1998, and seven years later Marvel launched a new series with Madrox as the lead character of a new X-Factor series, where most of the old team and some new members had become private investigators.

Technically, there have been three ''X-Factor'' series so far: one about the mutant superhero team, which started in 1986; a mostly unrelated series about FBI agents in the same universe, and one about the mutant detective team, which started in 2006. However, after Creator/PeterDavid took over the original series, the roster and style of the series was so different from what came before it that it was basically a separate series. So this page refers to four separate ''X-Factor'' series, meaning the original, starring the five original X-Men as mutants ''pretending'' to be CapeBusters, the second era of that same title, which began with PAD taking over and continued with several other writers, starring CListFodder as mutants openly working for the government; the newer series, also written by PAD but with an adversarial relationship with the government and more FilmNoir elements than most superhero comics, and finally the All-New era. The detective-era book eventually resumed the numbering of the old series, so the series breaks down into: vol. 1 #1-#70 (original X-Men), #71-#149 (government team), vol. 2 #1-#50 (detectives), then #200-the present (still detectives). The series concluded in late 2013.

In 2014, Marvel launched ''All-New X-Factor'', still with Peter David and renumbered ''again''. They're a corporate superteam now, with Polaris as their leader. Gambit and Quicksilver joined in the first issue. Their bankroller is the mysterious Harrison Snow of Serval Industries. The series concluded with issue #20.

Has nothing to do with the [[Series/TheXFactor reality series]].

* ''ComicBook/XFactor2006''
* ''ComicBook/AllNewXFactor''

[[folder:Original X-Factor]]
!!The first series provides examples of the following tropes:
[[caption-width-right:250:Same old X-Men, fresh new flavor.]]

* AnimalThemedSuperbeing: Wolfsbane when she was a member. It should be noted that, while Beast was also one of the founding members, he is more of a BeastMan than an ATS since he doesn't take after one particular animal or another.
* BatFamilyCrossover: "Inferno", "The Xtinction Agenda", and "The Muir Island Saga", the last of which led directly to the major lineup changes.
* BigBad: Apocalypse
* {{Brainwashed}}: Even though Warren had willingly agreed to serve Apocalypse in exchange for new wings (bear in mind he was [[DrivenToSuicide borderline suicidal at the time]], and everyone thought he ''was'' dead), Apocalypse still programmed him to be loyal. It wasn't thorough enough, though, and Warren rejoined X-Factor.
* BrainwashedAndCrazy: Havok during part of the "Inferno" storyline.
* CapeBusters: When they first started using the name X-Factor, the team pretended to be normal humans who captured mutants as an excuse to recruit young mutants to train.
* TheChessmaster: Cameron Hodge
* CloningBlues: Jean learns to deal with two beings copying her body. Madelyne, meanwhile, [[GoMadFromTheRevelation couldn't cope with the revelation]] of ''being'' a clone.
* EvilCostumeSwitch:
** Havok when he becomes the Goblin Prince to Madelyne Pryor (although the switch in question is really just his old suit reduced [[ShirtlessScene to tatters]] to match Madelyne's [[MsFanservice outfit]]).
** Angel, as Death of the Four Horsemen (he kept his costume after returning to X-Factor and becoming Archangel).
** Caliban, as a willing servant of Apocalypse.
* FaceHeelTurn:
** Angel (see {{Brainwashed}} above); Caliban (willingly); Madelyne Pryor (see CloningBlues); Havok (see BrainwashedAndCrazy). Angel/Archangel and Havok [[HeelFaceTurn came back, though]]. As did Caliban, but not until well after this incarnation of X-Factor.
** Havok ''again'', during "[[BatFamilyCrossover The Xtinction Agenda]]"; this time convinced he was a Genoshan hunter. [[HeelFaceRevolvingDoor He got better, again.]]
* FiveManBand: The same dynamic as the group was when they were the first ''X-Men'' team.
* {{Flashback}}: How Jean came back was summarized by Warren, although the AsYouKnow aspect for the first part was getting on Scott's nerves.
* InvasionOfTheBabySnatchers: Nanny and Orphan-Maker
* KickingAssInAllHerFinery: Jean plays with this when she wears an evening dress and fur coat, and then acts like a snowball fight with Scott is [[MundaneMadeAwesome an epic battle]].
* LittleBlackDress: Jean wears one in the first issue, and another in the three issue arc where she loses her winter coat and then replaces it with a fur coat.
* LosingYourHead: Memo to Cameron Hodge: don't kill the girlfriend of the guy with brand-new razor-sharp wings after you've already betrayed his team and ruined his life. Though Hodge [[DealWithTheDevil did plan ahead]].
* TheMenInBlack: The team's cover story at first was as an organization like this.
* PrettyInMink: Jean buys a white fur coat in issue #53, and some background ladies would occasionally wear fur.
** In issue #55, Hanks saves the life of a {{Streetwalker}} who is wearing a full length white fur coat.
* PuttingTheBandBackTogether: Jean gets the original team together to find a way to help mutants again (unfortunately Cameron Hodge takes advantage of that, among other things).
* {{Retcon}}: How Jean was brought back. But unlike ''Series/{{Dallas}}'', this didn't actually contradict any of the past events in the stories (although the later rehash "Endsong" would contradict events from the "Dark Phoenix Saga").
* SpinOff: Of ''The Uncanny X-Men''
* SnowballFight: #53: [[MundaneUtility Superpowers style]], with Jean even calling herself [[WinterRoyalLady "The Queen of the Icy North!"]]
* [[TonightSomeoneKisses Tonight Someone Proposes]]: Scott proposes to Jean in issue #53. She turns him down (but after some CharacterDevelopment, she successfully proposes to him a few years later).

[[folder:X-Factor 1990s]]
!!The second series provides examples of the following tropes:
[[caption-width-right:250:Welcome to the Nineties...]]

* AscendedExtra: On the second team, Multiple Man and especially Strong Guy, who had little personality and neither a codename nor a ''last name'' before joining.
* BatFamilyCrossover: Often lampshaded, as the cast usually doesn't fit in with the ComicBook/XMen's tendencies toward DarkerAndEdgier and {{Wangst}}. Doc Samson comments that they're "refreshingly normal" for a mutant team, and Strong Guy's wisecracking during the otherwise grim X-Cutioner's Song crossover leads Havok to say, "stop it, you're embarrassing me." During the Phalanx Covenant crossover, Strong Guy comments on how he hasn't even met most of the roster of the other X-Books.
* CatchPhrase: The initial government lineup tended to say "cripes" a lot. Then there's Strong Guy's made-up insult, "blork", his politically correct term for mutants "geecees" (short for "genetically challenged"), frequently threatening "I'll defenestrate 'em" when a villain does something [[KickTheDog offensive]], and several instances where someone responds to "nobody move!" with, "mind if I scratch my nose?"
* DeadlyRotaryFan: Rick Chalker attempts to use [[{{Cyborg}} rotors grafted in place of his hands]] as weapons, extremely incompetently.
* DeadpanSnarker: ''Everyone'' on the initial government lineup cracks wise, and ''three'' characters served as Designated Joker: Madrox, Strong Guy and ComicBook/{{Quicksilver}}. When their government liaison is unexpectedly teleported in, Strong Guy quips, "oh, good, the comic relief is here."
* FunPersonified: Madrox got a little more serious after discovering his duplicates are alive, and Strong Guy got a little DarkerAndEdgier after revealing a DarkAndTroubledPast and suffering a massive heart attack, but both of them actually ''cope'' with their pain through humor.
* GeniusBruiser: Strong Guy was a nerdy, grade A-student at junior high.
* LawyerFriendlyCameo: more of a reference really, but one issue revealed that the team's government liaison, Val Cooper, really envied her brother the FBI agent, who gets really cool cases:
-->'''Cooper:''' ...like one time, they found this girl. [[Series/TwinPeaks She was dead,]] [[MemeticMutation wrapped in plastic...]]
* MesACrowd: Madrox's mutant power.
* MundaneUtility:
** Jamie constantly uses his dupes like this, sending them out to learn and explore the world, creating them on the other side of locked doors, playing duets on piano (pity the only song he knows is "Chopsticks") and the above super-babysitting example.
** Quicksilver is shown reading books at super-speed, and everyone takes a crack at prying a stubborn lid off a jar of mayo, but even Polaris's magnetic powers and Havok's plasma blasts are useless.
* PrettyInMink: Lorna wore a fur-trimmed coat or two.
* PunchClockVillain: Random, a bounty hunter, is wreaking havoc in downtown Washington, D.C. because he's chasing a bounty. X-Factor arrives and defeats him, by paying him *more* than the bounty was worth.
* ShootTheShaggyDog: The 3 Chalker brothers' individual attempts to avenge each other's deaths as well as their combined vendetta once they were resurrected by a demon.
* ShoutOut: This book was written by Creator/PeterDavid. In the early nineties. [[SignatureStyle An abundance of pop cultural references were inevitable.]] See right below for one of many examples.
* StrangeMindsThinkAlike: Valerie Cooper, X-Factor's human government liaison, is buried in a ton of paperwork. [[Series/{{Blackadder}} Baldrick]], her assistant says to deal with the paperwork, [[ShoutOut "I have a cunning plan."]] After Valerie goes on about how Baldrick wouldn't know a cunning plan if it bit him in the arse says, "You don't suppose they'd know it if we burned it all." Baldrick admits this was his cunning plan.
-->"You ask me, I blame society."
* TonightSomeoneDies: Madrox, although [[UnexplainedRecovery he obviously got better]].
* WhatKindOfLamePowerIsHeartAnyway: The "power" of Vague from the aforementioned Hell's Belles was that she was ''transparent''. Not even invisible. Just transparent.
* YouGottaHaveBlueHair: Lorna's green hair.