[[caption-width-right:300:Same old X-Men, fresh new flavor.[[labelnote:Click here to see the retooled team]]http://static.tvtropes.org/pmwiki/pub/images/X-Factor_Vol_1_71_8887.jpg]]

''X-Factor'' debuted as an ''ComicBook/XMen'' spinoff in early 1986. For [[Franchise/MarvelComics Marvel]], it was the opportunity to bring the original X-Men together after so many years. For the record, ComicBook/{{Cyclops}} left the leadership of the X-Men to ComicBook/{{Storm}} and tried to live a quiet life with his wife Madelyne Pryor and their son. The ComicBook/{{Beast}}, Angel and ComicBook/{{Iceman}} had recently left ComicBook/TheDefenders. Thus, those characters were free game for other projects.

In addition to all that, it just so happened that a recently [[HeelFaceTurn reformed]] ComicBook/{{Magneto}} had been put in charge of the X-Men by Charles Xavier before the later left Earth for some years. And more importantly, it turned out that ComicBook/JeanGrey had not died a few years before. She was found sleeping in an escape pod in Jamaica Bay by ComicBook/TheAvengers, who brought her to [[ComicBook/FantasticFour Reed Richards]]. They all learned, including Jean herself, that the Jean Grey who became Phoenix early in Creator/ChrisClaremont's run and died in ComicBook/TheDarkPhoenixSaga actually ''was'' the Phoenix, who replaced Jean in Stephen Lang's platform.

Mr. Fantastic brought the news to Angel, who in turn called the other original X-Men, and they all reunited with Jean. They didn't want to deal with Magneto, so they formed a new group. They dedicated themselves to continuing Xavier's dream, with an odd twist: they masqueraded themselves as [[CapeBusters mutant hunters]] living in advanced headquarters, while secretely saving and training new mutants. And thus X-Factor was born, with Bob Layton and Butch Guice as the first creative team. Louise Simonson soon replaced Layton and milked the masquerade for all it was worth before discarding it and making X-Factor publicly mutant heroes, in contrast to the X-Men who were hidden outlaws at the time.

After the original members rejoined the expanded team of X-Men in 1991, Creator/PeterDavid took the series over. The title 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. The series was eventually cancelled in 1998.

In 2006, Marvel launched a new series with Madrox as the lead character of a new X-Factor team with more FilmNoir elements than before, where most of the old team and some new members had become private investigators. This book eventually resumed the numbering of the old series, so it breaks down into: vol. 1 #1-#70 (original X-Men), #71-#149 (government team), vol. 2 #1-#50 (detectives), then #200 onwards (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 with Polaris as their leader and the mysterious Harrison Snow of Serval Industries as their bankroller. Gambit and Quicksilver joined in the first issue. The series lasted 20 issues.

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

Following volumes with their own pages:
* ''ComicBook/XFactor2006''
* ''ComicBook/AllNewXFactor''
!!The series provides examples of the following tropes:

* AnimalThemedSuperbeing: Wolfsbane, being a werewolf-like mutant. Beast is more of a BeastMan since he doesn't take after one particular animal or another.
* 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: ''ComicBook/{{Inferno}}'' and ''X-Tinction Agenda'' involved X-Factor, the X-Men and the ComicBook/NewMutants. ''The Muir Island Saga'' led directly to the major lineup changes. Often lampshaded during the government era, as the new cast usually doesn't fit in with the X-Men'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.
* 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.
* 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?".
* 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.
* ColorfulThemeNaming: The vampiric Ravens all had names related to blue or red: Crimson, Azure, Coral, Cerise, Beryl, Ruby, and Cobalt.
* CustomUniform: The government team shared a common color scheme, with individual variations: Madrox's full cowl and BadassLongcoat, Havok's leather jacket and headgear, Strong Guy's coke-bottle glasses, etc. Quicksilver stuck out because he kept his traditional light-blue with silver lightning outfit. It fits his aloof and arrogant demeanor, but also shows his grudging acceptance of membership in the group of TrueCompanions that develops. Although when it's noted that the uniform is optional, Strong Guy says he wished somebody had told him that before he got one.
* 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."
* EpiphanyTherapy: An issue has the team engaging in therapy with Doc Samson (the universe's resident superhero psychiatrist). It helps some of them a little, and makes no difference to others. Then much of the original team goes back to him... and it's noted by Samson that they're significantly more messed up.
* 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 was brainwashed by Apocalypse into becoming the Horseman of Death; Caliban willingly joined Apocalypse to get a power-up for his revenge against the Marauders; Madelyne Pryor's sanity slipped after realizing she was Sinister's experiment all along; Havok was turned into the Goblin Prince by Madelyne. Angel/Archangel and Havok [[HeelFaceTurn came back,]] though. As did Caliban, but not until well after his incarnation in X-Factor.
** Havok ''again'', during ''[[BatFamilyCrossover X-Tinction Agenda]]'', this time convinced he was a Genoshan hunter. He got better, [[HeelFaceRevolvingDoor again.]]
* FiveManBand: The original group had the same dynamic as 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.
* 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: Beast, as always, except during his near-human phase. Also Strong Guy, who was a nerdy, grade A-student at junior high.
* InvasionOfTheBabySnatchers: Nanny and Orphan-Maker specialize in this. Nanny steals children to raise them as armored soldiers, and [[MeaningfulName Orphan-Maker]] kills their parents.
* 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]].
* LawyerFriendlyCameo: More of a reference really, but one issue revealed that the team's government liaison, Val Cooper, really envied her brother, a FBI agent who gets really cool cases:
-->'''Cooper:''' ...like one time, they found this girl. [[Series/TwinPeaks She was dead,]] [[MemeticMutation wrapped in plastic...]]
* LiteralDisarming: The "Judgement War" storyline culminates in Jean absorbing the energy of the alien factions of the planet where the arc took place, and transfering it to Scott to stop the Celestials' judgement. A cosmic symbol imprited on Arishem's hand could start the judgement process if his verdict was negative, so Cyclops destroyed the hand with a powered-up optic blast.
* 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 pretending to be an organization like this.
* MundaneUtility:
** Jamie constantly uses his [[MesACrowd 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 doing super-babysitting.
** Quicksilver is shown reading books at super-speed.
** Subverted when 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: Jean buys a white fur coat in issue #53, and some background ladies would occasionally wear fur.
** In issue #55, Hank saves the life of a {{Streetwalker}} who is wearing a full length white fur coat.
** 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.
* PuttingTheBandBackTogether: This is how the series starts. Jean gets the original X-Men team together to find a way to help mutants again.
* {{Retcon}}: How Jean was brought back. But it was done in a way that didn't contradict any of the past stories [[note]]although the later rehash "Endsong" would contradict events from the "Dark Phoenix Saga"[[/note]], by revealing Phoenix was going around disguised as Jean and Jean herself was alive, [[SealedBadassInACan if sleeping]].
* SharedMassHallucination: How X-Factor publically handwaved the demon attacks in ''Inferno''. Their explanation (mass hallucination caused by A.I.M satellites) works since the existence of scientific terrorists is accepted by the average joe. The existence of demons is apparently [[SelectiveObliviousness a totally different matter]].
* ShootTheShaggyDog: The three Chalker brothers' individual attempts to avenge each other's deaths as well as their combined vendetta once they were resurrected by a demon.
* ShoutOut: The government era team was written by Creator/PeterDavid. In the early nineties. [[SignatureStyle An abundance of pop cultural references were inevitable.]]
* SnowballFight: Issue 53 has it [[MundaneUtility Superpowers style]], with Jean even calling herself [[WinterRoyalLady "The Queen of the Icy North!"]]
* 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]].
* [[TonightSomeoneKisses Tonight Someone Proposes]]: Scott proposes to Jean in issue #53. She turns him down. For a few issues it becomes a source of angst and awkwardness for both of them until Scott goes "let's forget I asked and let's figure it out later, okay?". Some publication years and CharacterDevelopment later, [[spoiler:Jean is the one to successfully propose him]].
* VaporWear: In issue #212, ComicBook/{{Hela}} wears a dress that makes it clear [[http://marvel.wikia.com/wiki/File:Hela_(Earth-616)_from_X-Factor_Vol_1_212_0001.jpg she is not wearing any underwear]].
* WhatKindOfLamePowerIsHeartAnyway: The "power" of Vague from the Hell's Belles was that she was ''transparent''. Not even invisible. Just transparent.