The longer a movie franchise is, the bigger the chance it will implement a retcon at some point — that's just how things are. Sometimes retcons are done to fix a plot point that hasn't age well, or simply to bring new life to an aging series.

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Retcons are a creative gamble and they don't always work out as intended. Where some franchises were arguably saved or even defined by their retcons, others only made things worse for an already messy story.

10 IMPROVED: X-Men Merged Superhero Timelines Before It Was Cool

The Past And Future Mutants In X Men Days Of Future Past

It's easy to overlook just how innovative Fox's X-Men franchise really was – even if it did impact the comics. One of the series' biggest accomplishments was retconning two separate timelines into one satisfying movie, long before Doctor Strange introduced the multiverse.

After X-Men: The Last Stand and X-Men Origins: Wolverine underperformed, the mutants were rebooted with the stand-alone reset X-Men: First Class. The timelines fused in X-Men: Days Of Future Past, keeping fan-favorite characters and ideas while ignoring the rest. Though the series overstayed its welcome, this retcon paid off by being a great farewell and new beginning for old and new mutants respectively.   

9 GOT WORSE: Alien's Original Horrors Were Diluted With Every Sequel

The Xenomorphs Attacks The Ship In Alien Covenant

The true horror of Alien is that the ever-changing Ellen Ripley and audience knew almost nothing about the deadly Xenomorph (which wasn't even named as such in its debut). Every succeeding sequel, however, answered a question that didn't need answering, leading to the Xenomorphs' devolution from unfathomable terror to generic movie monster.

Every sequel tied Ellen and humanity to the Xenomorphs, implying that the massacre on the USCSS Nostromo was actually foretold eons ago. This was worsened by the Alien Vs. Predator movies and the Prometheus timeline, which over explained and retconned the Xenomorphs' origins so much that it was reduced to a spacebound feral animal.

8 IMPROVED: Halloween Went Back To Basics With Blumhouse's Retcon Trilogy

Michael Myers Lurks In A Cabinet In Halloween

What made Halloween scary wasn't Michael Myers' rampage, but his lack of rhyme or reason. The sequels erroneously rectified this, retconning Michael into either Laurie's brother or a demonic cult's avatar. This led to one of the most notoriously convoluted horror franchises ever, giving an otherwise simple slasher premise five timelines.

The last and current chronology is the soft reboot produced by Blumhouse Productions, which ignores everything except the low-budgeted original Halloween. While Laurie's decades later warpath against Michael has its share of flaws, Halloween story's is a return to form that embraces the original's brutality and simplicity.

7 GOT WORSE: The Terminator's Sacrifices & Stakes Were Undone By SkyNet's Endless Returns

An Aged Sarah Stands With Carl In Terminator Dark Fate

As far as most fans are concerned, The Terminator's story ended with the quintessentially 90s sequel Terminator 2: Judgment DayHere, Sarah Connor and a teenaged John Connor stopped SkyNet's future dominance after going through hell and back. Whatever sacrifices they made were rendered irrelevant by every sequel that came after.

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Despite stopping SkyNet's creation in Judgment Day, each Terminator sequel revealed that the artificial intelligence had a failsafe for literally every scenario, or it just rebranded (see: Genisys and Dark Fate). The first two Terminators were about defying fate, while everything that came after revealed that fighting SkyNet was futile and pointless.

6 IMPROVED: Friday The 13th Accidentally Retconned Itself Into A Campfire Story

Jason Makes His Kill In Friday The 13th

The Friday The 13th movies are filled with contradictions and inconsistencies, like when exactly Jason Voorhees died or what the reasons for his murderous rage and apparent immortality really are. Instead of wrecking the lore or characters, the series' habit of retconning Jason's myth actually boosted its appeal.

Jason's franchise has been often compared to a campfire story, which suddenly justifies its conflicting details. Every new group of campers seen in either the movies or spin-offs like the popular comics is familiar with Jason's legend, but the details always change. Even if this was mostly unintentional on the filmmakers' parts, Friday The 13th's retcons gave it a unique sense of meta depth.

5 GOT WORSE: Saw Retconned Itself To The Point Of Parody

Billy The Puppet Plays A Game In Saw

When it first came out, Saw was praised for its unpredictable twists and turns. For better and worse, this became the franchise's defining feature, more so than the grisly traps Jigsaw trapped his victims in. Each sequel tried its best to outclass its predecessor's twists, most of which broke all internal logic for the sake of a shock.

Retcons like revealing yet another surprise apprentice or Jigsaw predicting literally everything including his own death were shoehorned through flashbacks. The retcons got so bad that a Saw sequel's obligatory big twist became the main attraction, turning Jigsaw into an omniscient meme and the franchise into a convoluted guilty pleasure.

4 IMPROVED: James Bond's Retcons Turned Each Era Into A Unique Time Capsule

Daniel Craig Poses In The Bond Barrel In Skyfall

Minus the Daniel Craig Era and some recurring casting choices, the James Bond movies are famous for having close to no continuity. Each new Bond actor brought something different to MI6's best agent, such as characterization, allies & enemies, and worldbuilding – all of which retconned parts of the previous Bond Eras.

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This wasn't detrimental, since it allowed every Bond actor to have a unique era all to themselves. For example, the Roger Moore Era is a comical take on spy adventures, while the more serious Pierce Brosnan Era tackled post-Cold War politics. Today, the Bond franchise is an anthology of time capsules of different decades' filmmaking sensibilities and styles.

3 GOT WORSE: The DCEU Couldn't Settle On A Singular Vision & Became A Mess

The Original DCEU Trinity In Batman V Superman Dawn Of Justice

One of the biggest criticisms against the DC Extended Universe is its refusal to commit to a cohesive plan, and it shows. After Zack Snyder's deconstructions like Batman V. Superman: Dawn Of Justice polarized audiences, the DCEU suddenly diverted from its promise of a darker superhero franchise by aping the MCU's family friendly approach to diminishing effect.

The failures of the heavily edited Justice League and Suicide Squad convinced producers to abandon their original franchise plans to focus on stand-alone projects. While this resulted in better movies like Birds Of Prey, Shazam!, and The Suicide Squad that largely ignore previous entries, it came at the cost of the DCEU's original interconnected endgame.

2 IMPROVED: The Fast Saga Escaped Irrelevance By Retconning Itself Into A Live-Action Cartoon

The Fast Family And Hobbs In Fast And Furious 6

Initially, the Fast And Furious movies were remnants of the 90s-era extreme sports trends that were dying out by the time they hit cinemas. To avoid falling into obscurity, Dominic Toretto and his family evolved. The end result was retconning The Fast Saga from a crime-thriller to an action series, and it worked incredibly well.

From Fast Five onwards, the Fast movies played loose with genre and continuity. Dead characters inexplicably came back, new villains suddenly had generations long blood feuds against the Torettos, and the Fast Family became black ops spies on their off days. For ironic and sincere reasons, The Fast Saga became a household name thanks to its playfully explosive storytelling.

1 GOT WORSE: Star Wars Kept Backtracking For Nostalgia's Sake & Stagnated

Rey And The Resistance In Star Wars The Rise Of Skywalker

Star Wars is a victim of its own success, as every new project has to live up to the Original Trilogy's astronomically high standards. Everything from the Prequel Trilogy to spin-off movies were chained to fans' nostalgia, which discouraged creative risks and favored retcons that always looped back to the original movies.

The most egregious retcon happened in the Sequel Trilogy's finale The Rise Of Skywalker, which bent over backwards to erase the incredibly divisive The Last Jedi and remind fans of things they knew. This was done not for narrative or thematic purposes, but to appease a backlash so offensive that it sparked hate campaigns on social media.

NEXT: Star Wars: 10 Times Luke Skywalker Proved He Wasn't A Hero