Subverted in the 2011 Alpha Flight mini-series. Alpha Flight members were resurrected during Chaos War but without Puck, who appeared in Hell in one of Wolverine's stories after Chaos War. When he later appeared very alive in Alpha Flight's new ongoing, you might have expected the writers handwaving it and saying he returned with the others and that Puck from Logan's adventure wasn't him, right? Instead Puck admits he was indeed in Hell. He slew the devil, took over Hell, and then gave up his throne to return and save his friends.
During Kurt Busiek's run on The Avengers, a major plot point was the Scarlet Witch finding out that she has a mutant ability to control chaos magic (an Arc Welding of the various powers she had displayed in the past). When Brian Michael Bendis took over the book, one of his first acts was to have Dr. Strange reveal that Scarlet Witch's powers had been slowly driving her insane for years, and that chaos magic was a nonexistent thing she made up as she began to lose her mind — retroactively changing Busiek's version from a woman growing more confident to a woman losing her grip on reality.
In an issue of Mighty Avengers, writer Dan Slott struck back by revealing that "there is no such thing as chaos magic" is a lie that sorcerers like Dr. Strange have agreed to tell in order to weaken the power of chaos demons.
The What If? version of Avengers Disassembled also took a shot at this, revealing that "Dr. Strange" was really an illusion cast by Scarlet Witch, with the real Dr. Strange explaining that chaos magic is totally a thing, but very few people use it because of how chaotic and unpredictable it is.
Any Marvel Comics writer who dares turn his hand to writing Doctor Doom is certain to find that a later writer will take issue with his interpretation, and declare that the story was so "wildly" out of character that it couldn't have really been Doom — it was Actually a Doombot. At least one story suggested that (almost) every single appearance of Doom since the early '60s was a Doombot. Oddly, the story was otherwise quite good.
A case that would probably be seen as an Author's Saving Throw if Word of God hadn't been involved. During Battle of the Atom, a grown-up version of Runaways's character Molly Hayes showed up as a member of the evil Brotherhood of Mutants from the future, to the displeasure of many fans. Later, when Brian Michael Bendis announced he'd use the Brotherhood again, fans asked him if he was going to explain why Molly turned evil. Bendis responded by saying there was a thing he wanted to do during Battle Of The Atom but Jason Aaron and editor Nick Love stopped him, and with them no longer working on X-Men books, he was able to have his way. Soon after it was revealed that Molly and all other members of the Brotherhood (except Raze) were mind-controlled by their leader.
And then that got turned around on Bendis a few years later in X-Men: Blue, where the Future Brotherhood returns, and this time they're all evil, and very definitely not brainwashed.
This happens with John Byrne a lot. Most fans have just accepted that Byrne has one idea of continuity: his. If he returns to a book (such as The Avengers) that he previously wrote, expect all of the characters to immediately return to the characterizations and stories he was writing when he left, as if all of the ensuing continuity and characterization had simply not happened. Whether this is a good thing or a really terrible thing generally varies on the title, how Byrne wrote it originally, what happened since he wrote it, and whether you're a big fan of John Byrne or not.
When John Byrne took over Star Brand back in The '80s, he proceeded to launch one Take That! after another at the departing figure of ousted Marvel Comics editor-in-chief Jim Shooter. Star Brand was one of the Shooter-initiated The New Universe titles, and was the one that Shooter himself wrote personally. Byrne not only took ad hominem shots at Shooter personally, but had exposition characters hang lampshades on how implausible the events of Shooter's run was, and how stupid the protagonist Ken Connell had been. Early on in Byrne's run, Connell's girlfriend (a major cast member) got killed off; Connell later broke down and tried to get rid of his powers, destroying Pittsburgh (the hometown of both Connell and Shooter) in the process. This was referred to slightly in the Untold Tales of the New Universe story "Tales of the Mulletverse".
In the '80s, John Byrne had grown tired of Magneto's status quo as an Anti-Hero, and wanted him to fall from grace and return to a life of villainy. To achieve this, he and Walt Simonson wrote a story where he did indeed turn back into a villain, and released the New Mutants from his tutelage to boot. Chris Claremont was not at all amused by this, so he responded by writing a story that revealed Magneto was only pretending to be a villain so that he would draw negative attention away from the other mutants of the world.
One reason there's bad blood between John Byrne and Peter David has to do with Lockjaw, The Inhumans' dog. As created by Stan Lee and Jack Kirby, Lockjaw was just a very large, mutated dog with a normal canine intelligence level. Byrne later wrote a Thing issue in which Lockjaw spoke for the first time, begging that baby Luna not be subjected to the Terrigen Mists, since their effects weren't always pretty — implying that he was a full-fledged Inhuman like the others, and the Inhumans had always treated Lockjaw as an animal solely because he looked like one. Thus Peter David revealed that Lockjaw's "speech" had been a prank on Ben Grimm. (As he tells it, this was a request from editorial; David himself didn't have a problem with the scene and wrote his retcon so that it was possible it was Quicksilver that was lying.) This fixed the problems with Byrne's story, but now the Inhumans were Jerkasses for a different reason: pranking Grimm in the middle of an important debate, at Lockjaw's expense. Fans of the Byrne story remain sore about this... and others remain sore about the Byrne story.
When John Byrne took over as writer on the West Coast Avengers, a title previously written by Steve Englehart, he proceeded to undermine four years' worth of characterization. Hawkeye went from confident leader to sidelined jerk. The Vision and Wonder Man relationship, that had evolved into a bond of close fraternity, returned to one of jealous contention. Tigra went through almost the exact same story arc of losing control of herself and succumbing to her feline side that Engelhart had put her through and seemingly resolved. And the Vision and Scarlet Witch marriage... was altered. After the Vision lost his emotions, their children were discovered to be pieces of the devil, after which The Scarlet Witch went insane. For some reason Byrne decided to hit the Reset Button and return the characters to a status they had outgrown in over a decade of stories. Some have accused Byrne of wrecking a title that Englehart had arguably made a success out of resentment over how Englehart had written the Fantastic Four, a title John Byrne had made a hit, although it is just as likely a case of Creative Differences.
On the other hand, Byrne's portrayal of Iron Man in Avengers West Coast (and later in Shellhead's own book) stayed fairly close to how Bob Layton and David Michelinie had portrayed him, although he did remove the weapons-testing aspect from Tony's origin story. He also kept team newcomer U.S. Agent pretty much in line with how Mark Gruenwald wrote him in Captain America.
Byrne & Chris Claremont had a feud of sorts in the 1980's, which started when Claremont wrote X-Men #145 where Arcade basically punks Doom and the X-Men force him to apologize, followed by a later story where Lilandra of the Shi'ar gives Reed Richards a "The Reason You Suck" Speech for saving Galactus' life. Byrne responded by later revealing that the Doom that dealt with Arcade was Actually a Doombot, and had Doom admit that the X-Men weren't even worth his time. Later, in FF #264, Reed was on trial for saving Galactus and was told by basically every cosmic being in the Marvel Universe that yes, he was 100% right in saving his life.
The Civil War event was controversial enough for writers to start trying to retcon it to be more in keeping with their own ideas pretty much as soon as it ended.
After Mark Millar turned Iron Man into a fascist in Civil War, many other writers have had their character walk up to Tony Stark and berate him for his actions.
Only Brian Michael Bendis came close to rationalizing Stark's actions and that was in an uber-last minute filler story published AFTER Civil War ended, via retconning all of Tony's actions based around a never seen sequence where Tony Stark learned about Project Wide-Awake and the fact that the government was going to activate it and unleash the Sentinels upon the super-hero community. Bendis also outright absolved Hank Pym of his involvement in Civil War by way of a Skrull impostor.
Related to that, J. Michael Straczynski tried to rationalize Reed Richards' actions by having Reed relate the story of his uncle. Said uncle had spoken out against the Red Scare witch hunts of the 50's, and as a result, lost everything. Because he chose to speak out against unjust abuse from those in power, he ended up dying penniless and alone. Reed used this as rationalization for supporting the SHRA, arguing that the consequences for standing up against an unjust law were just too great. Needless to say, nobody was really happy with that, so Dwayne McDuffie completely ignored that explanation while having Reed state that through science, he'd discovered that Civil War was one of many potential horrific events that could potentially be on the horizon. Reed's calculations stated that Civil War was the only such threat that humanity could face without being completely obliterated, effectively making it the Lesser of Two Evils in his mind.
One of the big "Oh shit" moments in Civil War II #1 was when She-Hulk was critically injured during a fight with Thanos, an incident that left her scarred and comatose. The problem? Brian Michael Bendis chose to dispatch her with a stray missile, something that should not have had much of an effect on her given that she's survived much worse in previous comics. Kelly Thompson responded by Retconning the fight in an issue of A-Force, revealing that while the missile did injure She-Hulk, it wasn't strong enough to scar her or leave her in a coma. The actual thing that scarred her and left her comatose was Thanos giving her a brutal No-Holds-Barred Beatdown immediately after the explosion. She-Hulk herself even Lampshaded it:
She-Hulk: Missile to the chest... can't stop me... w-what, like it's my first day...?
During the time Wolverine's son Daken and Daredevil's enemy Bullseye were members of the Dark Avengers, Daniel Way and Majorie Liu, writers of Daken's ongoing series Dark Wolverine, tried to establish some sort of rivalry with a lot of sexual tension between the two, with Daken using his powers to manipulate Lester's emotions For the Evulz. Other writers decided to ignore it and wrote them as good friends with no rivaly or sexual tension whatsoever.
When Chris Claremont wrote Margali Szardos as "Sorceress Supreme" over in X-Men, the writer of Doctor Strange responded with a story revealing that she had been possessed and really had no magical powers at all.
During his run on Doctor Strange, Steve Englehart wrote a story in which Earth has been destroyed and Eternity created a perfect copy of it with all inhabitants and their memories. He also had a larger arc of the spirit of the Ancient One testing Strange to prove he was worthy of the title of Sorcerer Supreme. The moment Marv Wolfman took the title, he had Strange stripped of Sorcerer Supreme rank (Wolfman felt he shouldn't have such power) and revealed the tests were manipulations of new villains, one of them claiming Earth's destruction was only an illusion.
But wait, it gets better - after a few issues the story was taken over by Jim Starlin, who proceeded to reveal that the villains themselves were just pawns of his own creation - a being known as In-Betweener, who tried to fix the balance between life and death that was skewed towards death because of Thanos and had the Ancient One return to human form.
Then the story was taken over by Roger Stern who both did his best to connect all loose plot threads and throw some of his own. And so Strange beat the In-Betweener and explained that his actions were unnecessary, because Strange himself is a countermeasure to Thanos, the Ancient One casually returned to being one with the Universe, and it was directly stated Strange is as strong as ever and Sorcerer Supreme is nothing but a title. Years later, he would write a graphic novel in which Strange wins the title back and not only doesn't get any power boost, but now owes a favor to the guy who came in second.
Whether or not The Falcon was a pimp and drug dealer known as "Snap" Wilson before he became a superhero. Due to its dodgy implications, this bit of Sam's backstory has been retconned back and forth by multiple writers with varying degrees of success. The most recent word on the subject came in All-New Captain America, which stated that "Snap" Wilson was never real and was just a fabrication of the Red Skull.
Reading The Mighty Avengers you might get an impression that Dan Slott had some sort of continuity-war with The Incredible Hercules writers Greg Pak and Fred Van Lente - every time they tried to set the series in larger continuity on page or via Word of God, Slott would write something contradicting them. And when they poked fun at Ye Olde Butcherede Englishe Marvel gods were using back in the days, but stopped in early 00s, Slott wrote Herc returning to it.
The Marvel UniverseCrisis CrossoverSecret Invasion (2008), seemed like it was going to do this ("X wasn't really X, just a Skrull impostor!") much more than it actually did. It didn't help that fans had high hopes that this explanation would be used to excuse the many characters they felt had been written out of character in Civil War, or that many of the characters that were revealed to be Skrulls were not well received.
Dan Slott's final issue of She-Hulk was devoted entirely to explaining away events from other comics as alternate-universe doppelgangers who were visiting the Marvel Universe on vacation; this has since been largely ignored. The reveal was a "fix" to a story in Uncanny X-Men which had She-Hulk uncharacteristically sleeping with the Juggernaut. Before coming to our world, the doppelgangers were supposed to learn everything about their other self by reading a handbook, so they could act in character.
Years ago, Eric Larsen had the Spider-Man villain Doctor Octopus deliver the Hulk a severe smackdown during the "Revenge of the Sinister Six" storyarc. In the story, "Doc Ock" was given extremely powerful adamantium limbs which made him far more dangerous. Hulk writer Peter David accused Larsen of making a personal attack when he wrote that story and responded with a story written for the sole purpose of mocking Doctor Octopus. Larsen denied this, claiming he had used the Hulk to show how deadly Ock had become in a rather obvious demonstration of The Worf Effect. (And it made sense; what better way to prove a villain has Taken a Level in Badass than have him beat up the Hulk?)
This debate kicked up again years later in the letter-pages of Savage Dragon where David wrote in to accuse Larsen of making a personal attack when he wrote the Spider-Man story. Larsen explained that since Doc Ock was using Applied Phlebotinum in the story (he had much stronger adamantium limbs), it made sense to use the Hulk for the Worf Effect. David was not amused.
The What If? version of Spider-Man: The Other, by Peter David, basically starts with the Watcher explaining that the fundamental premise of the original story (by J. Michael Straczynski) is flawed, and this version is based on what was really going on.
Kurt Busiek's Untold Tales of Spider-Man featured stories set in between and around The Amazing Spider-Man. It stuck closely as possible to the old continuity of those issues. Many fans considered it the most entertaining Spider-Man book, especially since the series appeared around the time all the regular Spider titles were entangled in The Clone Saga mess. Then John Byrne came along.Spider-Man: Chapter One was his attempt to update the old Lee and Ditko stories and he pretty much disregarded most of what Busiek had done in his Untold Tales series.
Not too long afterwards, Paul Jenkins penned a Chameleon story-arc in Webspinners: Tales of Spider-Man - explicitly referencing his first appearance in Amazing Spider-Man #1 instead of Chapter One. Note that Jenkins didn't do so based on his own opinions. He simply asked editorial which story he should reference, and they answered with the original. To add insult to injury, this went down while Chapter One was still in progress - Byrne's mini-series being disregarded months before the final issue was on the stands. Additionally, events and characters from Untold Tales have since been mentioned or referenced.
When Nick Spencer took over writing The Amazing Spider-Man (2018) in 2018, the early issues had some noticeable potshots at former writer Dan Slott's portrayal of the character, with several characters even calling Peter out on irresponsible behavior made during Slott's run. Spencer's very first issue saw the long-awaited reunion of Peter and Mary Jane, with subsequent issues deconstructing their previous reasoning for not getting back together and ultimately refuting it. Unfortunately for Spencer, his efforts were for naught, as the two were immediately broken up again after Zeb Wells took over the comic.
Squirrel Girl is almost an Armed With Canon game of tennis. First, she was shown beating Doctor Doom. So a later appearance of Doom mentions it was Actually a Doombot (see above). Then Squirrel Girl beats Thanos, and Uatu is present just to say that it isn't a "robot, clone, or simulacrum". Later on, Thanos mentions that he can create clones of himself that even the Watcher cannot tell aren't him. So then another Squirrel Girl adventure goes back to the beginning - by having Doctor Doom be unwilling to fight her when she shows up in his castle. What's interesting is that all of this, except for her beating Doom and the Doombot reveal, was written by Dan Slott; he's having fun at one-player Canon ping-pong. There are also some fan theories that Thanos was lying about the ability to create indistinguishable-even-to-the-Watcher clones just to avoid admitting defeat. Not to mention that if a clone is perfect enough to fool the Watcher, one wonders just how different it is from the original anyway.
Speaking of Thanos and potential duplicates, there was a period in the '90s where his creator, Jim Starlin, felt he was undergoing Villain Decay. First came a Ka-Zar issue where the eponymous Badass Normal managed to (through contrived circumstances) survive a fight with Thanos, despite the obvious power disparity. Then came a Thor storyline where Thanos killed millions of people while trying to find a pair of cosmic artifacts needed to destroy the universe, which ended with Thor kicking his ass. Finally, there was Avengers: The Celestial Quest, a mini-series where Thanos was forced to team up with the Avengers to stop Rot, Thanos and Death's offspring. Starlin was not amused, so he wrote Infinity Abyss, a mini-series that retconned all three of those appearances into being mentally deficient clones, explaining away what Starlin felt was needlessly-destructive and Out of Character behavior. For added points, he had Thanos mention that the clone who had faced Ka-Zar was a "low-level" one, explaining how Ka-Zar had managed to hold his own and not die.
Thanos was later the main antagonist in a high profile crossover between The Avengers and the Guardians of the Galaxy. Brian Michael Bendis' depiction of Thanos was noted to be hugely Out of Character, emphasizing his more generic Evil Overlord tendencies and suddenly having him be obsessed with conquering the Earth. In Starlin's subsequent Infinity Revelation graphic novel, Thanos claimed that his recent obsession with Earth had come out of nowhere and surprised even him, and it was later revealed that his odd behavior under Bendis was actually the result of cosmic manipulations occurring ahead of a massive, universe-altering event.
Another Starlin example: Annihilus was killed near the end of Annihilation after Nova tore his heart out, and was subsequently reborn as a child with all of his past memories. Certain artists and writers seemed to forget this, and incorrectly depicted him as an adult. Starlin's Thanos vs. Hulk mini-series cemented once and for all that Annihilus was still a child, and that the adult Annihilus seen in other titles was just a robotic duplicate he used for public appearances.
Marvel's editor-in-chief Axel Alonso attracted quite a bit of controversy when he tetchily claimed in an interview that Marvel's Hercules was 100 percent heterosexual, despite numerous hints to the contrary in past comics and homoerotic content in certain original Greek versions. Jason Aaron clearly disagreed with that statement, and penned this bit of dialogue in Mighty Thor #702 to make it clear where he stood:
Hercules: It has been far too long since I have kissed a Thor.
In the Ultimate Marvel universe, in Cataclysm: The Ultimates' Last Stand, Brian Michael Bendis had Ultimate Reed Richards perform a Heel–Face Turn and set out to atone for the evils he'd committed as The Maker in The Ultimates, written by Jonathan Hickman. He was also shown atoning in Ultimate FF. However, Hickman wasn't done writing Reed as a villain, and later revealed that Reed had only been pretending to be good so he could continue his evil work without constantly having to worry about superheroes trying to stop him. This characterization was the one that he used in Secret Wars, and which extended to his appearances as a Canon Immigrant to the main Marvel Universe.
Bendis was also the only writer of Ultimate Spider-Man, and introduced Ultimate Spider-Woman. All-New Ultimates, by another author, changed her suit and renamed her as "Black Widow". Bendis simply ignored those changes and restored her suit and name in Ultimate End and Spider-Men II.
The notorious X-MenContinuity Snarl relating to Xorn's true identity and motivation basically happened because other X-writers (and a vocal element of the fans) thought that Grant Morrison's views on Magneto as indicated in the original arc ("he's a vicious, genocidal fanatic and all those Heel–Face Turn periods were out of character") were hostile Armed With Canon against them and responded in kind.
During the Secret Wars (2015), Cullen Bunn wrote Deadpool's Secret Secret Wars — which purported to tell the true story of what happened in the original 1984 event and featured Deadpool briefly bonding to the Venom symbiote. Many fans dismissed this as a What If? story, but in 2017 Bunn followed it up with Deadpool: Back in Black — which he proceeded to include references to in Poison-X and Deadpool: Assassin; mentioning on social media that Secret Secret Wars and Back in Black were 100% canon. When Donny Cates took over writing Venom, he made it clear on Twitter that didn't consider them canon - sparking a brief argument between Cates, Bunn, and X-Men senior editor Jordan D. White.note Who sided with Bunn in saying they were canon and explained why Deadpool wanted to be friends with Spider-Man. The disagreement over their canonicity was Played for Laughs during Absolute Carnage, where in the Absolute Carnage vs. Deadpool tie-in Carnage realizes Deadpool has a treasure trove of codices from bonding with four symbiotes, with an Editor's Note appearing and points out that Deadpool technically has five due to the Back in Black mini-series before another Editor's Note pops up saying "No, we're not using it."
Jason Aaron introduced a controversial retcon in the 2018 run of The Avengers where The Mighty Thor is revealed to actually be the son of Odin and a primeval incarnation of The Phoenix, contradicting decades of official lore in which Thor's biological mother is the earth goddess Gaea and his adoptive mother is Odin's wife Freya. Donny Cates used his position as the author of Thor (2020) to retcon this away in the "God of Hammers" storyline, with Thor defeating a powerful enemy by calling on the aid of his mother in issue #22. Cue the earth itself rising up to form a vortex of whirling stone and magical energies that allow Thor to trap and contain his foe, with one of Thor's allies explaining to the confused Avengers that this phenomenon is a gift to Thor from his birth mother, Gaea. Aaron promptly fired back in issue #54 of his run on the Avengers, introducing a threat in the form of a dimension-traveling Dark Phoenix followed by an enslaved Thor whom she refers to as her "son", and with the current Phoenix-host Echo repeatedly telling Thor that he needs to accept that the Phoenix is his mother. Aaron clarified later in Avengers 1,000,000 BC #1 that Firehair, the Phoenix of that time, is Thor's mother in only a symbolic sense; she convinced Gaea to give Odin a chance romantically and, at Thor's birth, breathed life back into him when Laufey turned the infant thunder god to ice - and promptly got attached. The current status quo is that Gaea is his birth mother, Freya is his adoptive mother, and Firehair/the Phoenix is his godmother - which seems to have more or less appeased all parties.
In The Sensational She-Hulk #36 by John Byrne gives us a very literal case of this trope, as we are suddenly introduced to She-Hulk's extended family of brothers, sisters, in-laws, nephews, and nieces. She-Hulk, unamused, takes out the Master Edition of The Official Handbook of the Marvel Universe and uses it to recap her known relatives up until then, noting that she's supposed to be an only child. She further adds that she doesn't want Marvel to build on the precedent set by her cousins the Hulk and Brawn. The extended family is promptly kicked out of the house and never heard from or acknowledged ever again.
The second volume of X-Men Forever was basically a way for Chris Claremont to tell the stories he'd wanted to tell before leaving X-Men the first time. As a result, a lot of concepts he didn't care for (Cable being Cyclops's son, or Madelyne Pryror's turn to baby-killing evil) are ignored, while things he wanted to make are made concrete, like Sabretooth being Wolverine's father.
Films
Deadpool 2: During the end, after Wade uses Cable's time-travel device to give Vanessa's killer a cream cheese spreader in the brain, his other stops include 2009 for the Weapon X Deadpool entrance scene from X-Men Origins: Wolverine, that movie's version of the character notorious for not being well-received. A bullet in Weapon X's head cleans up the timeline.
dodgy implications, this bit of Sam's backstory has been retconned back and forth by multiple writers with varying degrees of success. The most recent word on the subject came in All-New Captain America, which stated that "Snap" Wilson was never real and was just a fabrication of the Red Skull.
, to Sony's Spider-Man: Across the Spider-Verse having Miguel O'Hara refer to the events of Spider-Man: No Way Home as being caused by "Doctor Strange and that little nerd on Earth-199999." This extends to the Marvel wiki