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You Already Changed the Past
aka: You Cannot Change The Future

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"Things have their shape in time, not space alone. Some marble blocks have statues within them, embedded in their future... Any moment now, Janey's watchband will break. Somewhere, the fat man is already lumbering toward the shooting gallery, steps heavy with unwitting destiny."
Dr. Manhattan, Watchmen

You go back in time to Set Right What Once Went Wrong, only to discover that the "changes" you're making to the past were what "already" happened anyway. In other words, there was no "first time around" - the past only happened once, there were no different "versions" of it, and the changes you made to the past ultimately created the very past you read about in the history books before leaving on the trip.

It's like being Time's own personal Unwitting Pawn.

This does not necessarily mean that You Can't Fight Fate. For example, if Bob wanted to go back in time to stop Alice's death, he could simply convince his past self that Alice still died in the future. Following this logic, Alice never dies at all — and Bob suddenly remembers how several months ago, some "other" Bob came up to him insisting that Alice was going to die of something and the two of them had to go save her, which they did, so she's still very much alive and well all along. (Do you have a headache yet?) Or to avoid the headache and ensuing paradox, Future Bob could go back and save Alice in such a way that Past Bob still thought that she died - then drop her off in the present - kind of the present, anyway. The future. Past. Something.

Needless to add, grammar can sometimes become thoroughly useless at trying to put the point across, as all sense of tense gets thrown of the window. This trope is easier to observe rather than analyze.

This trope arguably makes the most sense when considering time travel from a scientific point of view, see the Novikov self-consistency principle.note  However, the number of time-travel plots that it allows for are extremely limited and the logic gets complicated very quickly. This, however, also has the side-effect of creating a 'self-correcting universe' usually by a slew of Contrived Coincidences (e.g. if you try to shoot your grandfather the gun will jam; if you try poisoning him he will recover; if you try strangling him you will be overcome; if you wear Power Armor from the future you will have second thoughts; if you try sending a bomb back through time and detonating it directly inside his chest the time machine will break down). This can also lead to a scenario where the only reason why the past is not changed is because someone else says 'you cannot' and you take his advice. Meaning the advice itself is a part of the universe's self-correcting nature.

Thus, most time travel stories that involve altering the past will provide some of the characters with Ripple-Effect-Proof Memory. This makes less sense, but it makes for a narrative convenience. If a You Already Changed The Past plot is used, the time travel will probably be a one-off thing, since repeating it would most likely get tedious.

The Ancient Greeks and Norse loved the notion that You Cannot Change The Future, and their works heavily imply that they believed in this specific notion of time (which even the Gods were trapped in). Although they used predictions rather than time travel, the effect is the same. Many first-time readers of the classics who don't buy into this notion of time, or don't realize this is why You Can't Fight Fate in the classics, have a hard time accepting The Fatalist behavior of classical Greek and European heroes.

See also Self-Fulfilling Prophecy. Compare Retroactive Preparation, where having changed the past already works to your favor. Related to Stable Time Loop where you go back in time, because you already changed the past. If the story focuses heavily on an attempt to change the past only to reveal right at the end that the past can't be changed, the result is often a "Shaggy Dog" Story.


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    Anime & Manga 
  • Rave Master: After much time is spent freaking out over what horrible ways they've twisted the past, Sieg, Elie, and Haru (but mostly Sieg) discover that all their actions caused the future they were trying to protect by not taking those actions. Haru made it very clear to the knight that the criminals he brought had invaded the castle ten days earlier, and that the knight was to take credit for catching them, which we see him talking about at the time Haru gave 50 years later. Getting Resha kidnapped enforced the king's decesion to have her fake her own death, leading her into the future where she get's amnesia and meets Haru, and ditching Sieg in the past leads to him being there to set the whole time loop up and make sure they mess with the past like they're supposed to.
  • Red River (1995): Yuri is sent back to ancient Turkey, during the Hittite Empire. She tries to keep a low profile, but events result in her obtaining the valuable iron ore for the Empire, as well as gaining power. Yuri thinks that she's changing the past in ways that it shouldn't, but her being sent back is what resulted in the events of history as it's known in her original time.
  • Tsubasa -RESERVoir CHRoNiCLE-. Details would be massive spoilers, but suffice to say that time travels differently in different universes, and something the heroes do midway through in a world that later turns out to be their own past sets up the very premise of the story, as revealed in the finale.
    • Also, one character who pulls a Face–Heel Turn halfway through is fated to pull a Heel–Face Turn back, given that his future self, who actually reincarnates in the past is the protagonist's father. Yeah...see, all grammar is useless. In fact, depending on which angle you see it from, the whole story wouldn't have happened if the past had not already included the influence of the future.
    • However, the first instance of tinkering with time that we knew of was not an example of this - the group visits the world of Shara twice, before and after visiting Shura which turns out to be the past of Shara; and the effects of their actions are quite visible. CLAMP seems to have lost track of their time-travelling system as the Mind Screw got more and more complicated...
  • Urusei Yatsura has time travel in a few occasions.
    • In one, Lum goes into the future where she brings back Ataru's diary. He reads it and believes things will go right for him, but attempting to cause them makes everything go horribly wrong. It's later found that when writing the entry about everything that went wrong, his tears blur the ink, causing it to look like he wrote about things going well.
    • In the other, the cast goes back in time to prevent Mendo from getting claustrophobia and nyctophobia. As a result, young Mendo pisses off the modern Mendo, causing him to attack his younger self. While hiding from his older self, young Mendo was trapped in a dark jar, causing him to grow deathly afraid of dark and tight spaces.

    Comic Books 
  • At the end of Atomic Robo volume 8, the title character is blasted into the 1800's, in spite of his long-held belief that time travel is impossible (due to the speed at which planets are constantly moving). He spends the first few years terrified of changing things and causing a paradox, but when pushed to act he settles on this trope.
    "Don't do anything. Except for what you were always will have done. It's not a paradox if I was already part of the past."
  • A Blade series had Doctor Doom lure the Daywalker to his castle, where Doom then proposed Blade with going back in time and saving his mother from a vampire attack. Blade asked him why he should do it, and Doom replies with "Because I've already seen you do it in the past." Doom is nice enough to give him a serum which would suppress his bloodthirst though.
  • Doctor Doom's debut in Fantastic Four #5 has him send the heroes back in time to collect the treasure of Blackbeard the pirate for him. In order to do this, they don disguises and the Thing distinguishes himself so well at the swashbuckling that the pirate crew rally around him, electing him to captain the ship and give him a pirate nickname to match his appearance: Blackbeard!
  • An issue in The Mighty Thor series had an storyline where Loki sends himself back through time with the aid of Hela to accomplish certain tasks that had already been mentioned in a previous issue, but with certain details left unclear. Turns out that Loki was responsible for many of the major events in Asgardian history, but it's left unclear whether they still would have happened had he never gone back in time. Even he isn't completely sure. He lampshaded this trope, saying that he cannot change the past and make the future play out a different way, but he can make sure it will go the way it did.
  • In the "Dead-End Kids" arc of Runaways, the team is sent back in time to the 1900's to avert a catastrophic gang war. As it turns out, the only reason the gang war boiled over was because the Runaways went back in time; as it turns out, one of the gangs back then was under the control of Gertrude Yorkes's time-travelling parents, and when they discovered that their daughter was dead, they decided to fire up the gang war in hopes that the other Runaways would be killed.
  • Subverted in the crossover Spawn/Wildcats, where future versions of Grifter and Zealot (the former being the original's future self but the latter being a new Zealot) are sent into the past to slay Spawn to prevent him becoming a ruthless dictator known as the Ipsissimus. When they fail to kill him, the present Wildcats and Spawn agree to go with them into the future to defeat the Ipsissimus, but it turns out this was part of a predestination paradox, as the Ipsissimus uses the opportunity to give Spawn the medallion that corrupted him and caused him to turn evil to begin with. When back to the present, the influence stats, and Spawn starts Evil Gloating... until the future Wildcats realize their mistake and make a last attempt to modify a minor action in the past. This causes Spawn to recognize future Zealot as an adult version of his widow's daughter Cyan, come back to his senses and hand the medallion to her, thus preventing the future.
  • The time travel of The Transformers: More than Meets the Eye is like this, specifically of the Stable Time Loop variety - the war that Brainstorm invents time travel to prevent turns out to have been DIRECTLY caused by time travel. On top of this, he was created because of the war, and had sold himself to the Decepticons to fund his project, which was why our heroes on the Lost Light believed he was going to kill Optimus and so followed him...
    • Then they threw in a few Stable Time Loops of their own - To go into all the ways the Crew mucked up the future by travelling back in time to fix it/stop it from being changed would take up the best part of this page
    • Brainstorm tries again to stop the war by going further back, but the Crew follow him to stop him again (still thinking he's after Optimus in some way), and they all just create more time loops that keep any loops in the future on track. When they all return, nothing in the past has changed and time is as much on track as ever. Except there's now a parallel universe, of course.
    • The most notable example is how Time Travel is the cause of the legend of the Sparkeater - because Whirl took a gun from Brainstorm's lab that turns people into Sparkeaters, which was only created because Brainstorm met a Sparkeater early on in the comic (which had been made by his gun millions of years ago, no less).

    Fan Works 
  • Always a Ranger- an AU of the confrontation with Thrax where he attacked the SPD B-Squad rather than the Operation Overdrive team- features Jen Scotts as part of the team of past Rangers recruited to replace the depowered Rangers. When they question how she was recruited from the past if she came from the year 3000, Jen reveals that after her last meeting with Wes, she checked historical records and realized that she was meant to become Wes's wife all along, prompting her to return to 2004 on a full-time basis.
  • In Binding Resolution, Hat Kid accidentally drops a Time Piece and travels back in time. When she realizes that the Nice Prince who's helping her is the same person who would later go on to become The Snatcher, she does everything in her power in order to prevent the transformation. This turns out badly because, despite her efforts, the future she tried to prevent was inevitable, as well as realizing that she had a key part to play in instigating the events.
  • Female Queens and Marco centers around Marco Diaz time-traveling throughout Mewni history and interacting with its previous queens. When he meets Queen Solaria, Marco tries to avert the Fantastic Racism in present day Mewni by showing Solaria that peace and diplomacy is a better alternative to fighting, and appears to succeed to a degree... until a case of Not What It Looks Like and Never Found the Bodynote  has Solaria believing that Marco is dead, leading to her hatred of monsters not only returning, but increasing and ensuring that Mewni's hatred towards monsters will persist to the present day.
  • In the Charmed (1998) fanfic Once and Future Witches, an attack on Leo and Wyatt causes the Charmed Ones of 2007 (just after the series finale) to go back to early season two and then all six of them go back to 1983. Once in that time, they are able to identify their foe as a demonic presence that exists outside of time and whose Darklighter agent had already killed Lynn, who Prue remembers as their childhood babysitter but was actually their first Whitelighter. However, since the Halliwells were travelling in time when Lynne was killed, Grams confirms that this means history hasn't been changed yet and Leo was always going to be the sisters' Whitelighter.
  • So you time travel to the future and your classmate gets punched... plays with this:
    • The akuma Time-Turner sends Miss Bustier and most of her class twenty years into the future, aside from Chloe and Marinette (the latter having transferred to another class one month prior). This results in them learning how Lila deceived them all... only the revelation comes far too late. All of the critical events that led to most of the class suffering Laser-Guided Karma have already happened; they just haven't been hit by the fallout yet. As a result, the people explaining this to them in the future are able to detail just what's in store for them all, knowing that even when they go back to the present, they won't be able to prevent what's coming.
    • The ending also reveals that one of the reasons why everything was set in stone is because the next-generation heroes from the future decided that since they were already going to be traveling back in time to return the class safely, they might as well take down Hawkmoth and Mayura first.

    Film - Live-Action 
  • Alice Through the Looking Glass carries the message that while changing the past in Underland is impossible, you might be able to learn from it. Alice discovers this the hard way when she tries to prevent the childhood accident that caused the Red Queen's giant deformed head. Originally Iracebeth hit her head on a grandfather clock that was being carried across the street, but when Alice manages to knock the clock out of the way young Iracebeth ends up tripping and smacking her head on a stone ledge anyway.
  • Back to the Future:
    • Played with in Back to the Future, where Marty goes back in time and introduces 1985 concepts to 1955, but the movie implies that he only changes the source of the original idea without majorly altering their progression into the modern day. He didn't invent skateboards but he introduced skateboarding to Hill Valley earlier than would have caught on naturally, and he didn't write "Johnny B. Goode", but hearing his guitar solo inspired Chuck Berry over the phone. Since these things don't actually change the future, it looks like they were always that way. His comment also inspires the busboy Goldie Wilson to go into politics, although Wilson was already mayor in the original timeline, meaning he would have found inspiration elsewhere.
    • In Back to the Future Part II, Doc's letter at the end sort of plays this trope straight (the only part of the trilogy to do so), though Rule of Cool applies for obvious reasons. This is debatable however, as since the letter arrives after the DeLorean gets struck by lightning, it could be argued that the Western Union guy wasn't there at all until the ripple effect kicked in. Alternatively, since Doc took The Slow Path to send that letter, the ripple effect kicked in a long time ago, the viewer just doesn't get to see it. The Western Union guy is the only instance of a character being present (and on-screen) for an altered event rather than simply having or, in Marty's case, being a ripple-affected artifact that's been temporally displaced.
    • In Back to the Future Part III, the 1955 Doc averts this. He specifically sends Marty back to a point in 1885 after 1985 Doc has left the letter with Western Union. As seen in Part III, they didn't do anything about it, which allowed for normal 70+ year delivery: "and the Western Union guy lost the bet!".
  • Bill and Ted:
    • Bill & Ted's Excellent Adventure: One of the signs that Bill and Ted are clever if not book smart is their recognition of this trope; they realize that to solve a problem in the present, they can use their time machine to plant helpful items in the past, and then they'll be there for their present selves to discover - and they keep reminding each other "Once this is over, we have to go back and place all that stuff!"
    • The entire climax of Bill & Ted's Bogus Journey is B&T and the Big Bad performing dueling versions of this. Except that, as Bill points out, only the winner can change history, so all the things the villain thought he planted were just decoys B&T placed to lull him into a false sense of security. In fact, as dumb as Bill and Ted usually are, they tend to be very smart when it comes to this trick.
  • Déjà Vu (2006): The first few attempts at actually changing the past just end up causing things the characters and audience have already seen happen. Eventually, for the sake of having a happy ending, they do manage to make a change that works. This could be a case of subversion, as it was mentioned in passing during the course of the movie that a big enough change could change the future (i.e., not having the ferry blow up). As The Other Wiki has a diagram showing at least four runs of the timeline are needed to explain how the events of the movie are possible, perhaps several trips of smaller changes adds up to one big enough change.
    • One moment that especially sells it is with regards to Claire's fridge. While investigating her house in the present, Douglas sees somebody had left the message "u can save her" in the magnet letters on the fridge. When he travels to the past and saves Claire, he writes the same message on the fridge only for her to reappear having changed into new clothes, the same ones she was wearing when she died. Douglas realizes he hasn't really saved Claire yet and tells her to change into something different.
  • The Final Countdown: Martin Sheen is sent on a mission by the mysterious billionaire he's never met. The aircraft carrier is sent back in time and almost prevents the attack on Pearl Harbor and loses one of their officers. When the ship returns to the present Sheen finds out that the mysterious billionaire is that officer, made wealthy by 30 years of fore-knowledge.
  • Godzilla vs. King Ghidorah: The Futurians mistakenly believe that they can alter the past, which leads them to try to erase Godzilla (not the first one, who was killed in 1954, but the second one, who has been attacking Japan since 1984) from history. Thinking that Godzilla was simply a living, but otherwise ordinary dinosaur until a hydrogen bomb test in the 1950s mutated him into a monster, the Futurians go back to the 1940s and move the dinosaur far away from the test, then head to 1992 to see if Godzilla has ceased to exist. It turns out all they did was cause history to play out the same way it already had: the spot they moved the dinosaur to is contaminated by radiation from a wrecked nuclear sub some time around 1979, mutating the dinosaur into Godzilla and causing him to attack Japan in 1984 right on schedule. The Futurians never seem to realize that they were trying to undo events that they themselves caused.
  • La Jetée: The protagonist's anchor to the past is his hazy childhood memory of seeing the beautiful woman at the airport, and then seeing a man die. Eventually, when trying to flee the scientists, he travels back to the past and to that moment—and gets shot by the jailer. So what he saw as a child was himself getting killed, after having fulfilled his mission. The remake 12 Monkeys has the same scene with a twist: he is shot by airport security trying to prevent the apocalypse that made him time travel in the first place.
  • An interesting case is the movie Paycheck. What happens to the protagonist (he is administered a procedure which would erase all of his memories from the coming two years; when he is finished, he's told these two years already happened) would be a perfect example of this trope. Only there's no time travel (though the plot revolves around a future-seeing machine).
  • In the 2007 film Premonition, Sandra Bullock lives the week of her husband's death out of order. She's unsuccessful in her attempts to save him, as on the last day she accidentally causes his death by preventing another one.
  • Star Trek IV: The Voyage Home: Harve Bennett's explanation for why the Enterprise crew was so careless about altering history seems to be (he says it in a rather disjointed way) that this trope is in place. Although this contradicts how time travel is usually portrayed in the series, it does fall into line with the one episode of the original series that also used the "slingshot around the Sun to visit 20th century Earth" method.
  • Tenet: Neil often says that "Whatever happened, happened" when The Protagonist intends to change the past. Indeed, whenever the characters invert and go back in time, they end up causing the events they witnessed the first time around. For example, The Protagonist fights himself in the Freeport while wearing a gas mask and a hazmat suit (this way, he doesn't recognize himself and doesn't touch his self past's skin, which would kill him), and also drives the Saab that he once saw un-crash on the highway. And Kat is the woman she herself saw jumping off Sator's boat in Vietnam.
  • The Terminator follows this exact method (the second movie and on go for different rules of time travel). It also gives a rare example of the good guys directly benefiting from the immutability of time. The machines sent back a Terminator to kill Sarah Connor before her son John Connor was born, in response, the rebels send back... the guy who becomes John's father. Also, in a deleted scene, it turns out that Cyberdyne, the company that built SkyNet and the original Terminators, acquired the remains of the Terminator. The sequel shows that they'd begun reverse engineering the Terminator, which would presumably have led to the creation of the Terminators had the events of the sequel not occurred, so it happened on both sides.


By Author:

  • Connie Willis:
    • To Say Nothing of the Dog involves time traveling historians (which first appeared in her Doomsday Book) who spend a lot of effort to repair the "incongruity" caused when one of them inadvertently brings a cat forward from Victorian England (they're extinct in 2057). This involves trying to make sure that the cat's owner winds up with the "Mr. C" that her diary specifies after they've accidentally introduced her to a different man. It turns out that all perceived incongruities are the continuum's self-correcting system.
    • Blackout and All Clear have a similar example. Some historians go back to WWII era, then find that they can't get home. They agonize over every little thing they do, worried that the slightest change might cause the Germans to win the war. It turns out that the things they did, the people they saved, and so on, were exactly the tipping points to let the Allies win the war. Their future, in which the Third Reich fell, predicates on them getting stuck in the past and doing the things they're convinced will ruin everything.
  • Isaac Asimov's works:
    • The short story "The Red Queen's Race" has a character who tries to make this trope happen. He was asked to translate several modern books on physics into ancient Greek, with the work being beamed back into humanity's past. History fails to change because the translator was very careful to leave out most of the advanced material, only including information which would account for discoveries and advances already present in our own time line.
    • Inverted in The End of Eternity. Despite changing history themselves all the time, the Eternals are certain that the existence of their organization is guaranteed by this trope—how can they eliminate their own existence? The exception, an Eternal who is certain that time loops are intrinsically unstable, turns out to be correct, and Eternity eliminates itself.
  • Robert A. Heinlein:
    • The Door into Summer. Various instances of Human Popsicle, but more importantly a weird time machine that has an equal chance of throwing the subject forward or backward. The protagonist uses it knowing he HAS to be sent backwards. Bonus points to a throwaway gag that suggests that Leonardo da Vinci is (and always has been) an accidental time-traveler.
    • His short —All You Zombies— involves a time agent making sure he completes the correct steps to finish the changes he remembers happening earlier in his life.This includes sending himself back in time to impregnate himself before his sex was forcefully changed, causing his female past self to give birth to... himself.
    • And in his By His Bootstraps, the protagonist is introduced to time travel by a man from the future, and shortly finds himself meeting himself twice, and each self gets trapped into saying and doing the same things he saw and heard said before. Eventually, he gets the drop on the man who introduced him to time travel by traveling into that man's past 10 years, only to find out he's waiting for himself.
  • Stanisław Lem pumped this to the max by time travellers creating the whole world from the physical constants up. What started as an attempt to make things better for everyone ended with our reality because of bureaucracy, competition, attempts of personal gain, human mistakes etc.

By Title:

  • Animorphs: In the second Megamorphs book, the Animorphs go back to the time of the dinosaurs. While there, they find two groups of aliens at war with one another, the Mercora and the Nesk, and take the Mercora's side. Meanwhile, they're also trying to get back to their own time period, which will apparently require a nuclear explosion, and so they steal a nuke from the Nesk. This causes the Nesk to leave the planet angrily, but not before diverting the path of a comet that was originally going to narrowly miss the Earth so that it crashes into it instead. Most of the Animorphs want to use the nuke to destroy the comet and save the Mercora, but Tobias has Ax sabotage the nuke in a way so that the Mercora won't realize it's a dud until it's too late, having realized that the evolution of mammalian life as they now it depends on that comet striking.
  • Tim Powers plays with this trope a lot in The Anubis Gates. The time-traveling protagonist comes to believe that You Can't Fight Fate, then learns that it's not that simple, since historians don't know all the details.
    • He encounters the brand-new original manuscript of a poem he'd studied in his own century, and wonders how it would pick up the stains he'd seen on it in his own time. A poet he recently met then walks in carrying some food, puts it down, and picks up the manuscript with his greasy hands to look it over.
    • He encounters a 17th century book with an inscription in it that shakes him up. He later travels accidentally to that century, and on encountering the then-new book, writes the pig-Latin inscription addressed to himself that he would read in the future.
  • Eoin Colfer's Artemis Fowl Time Paradox The matter is discussed before they actually Time Travel and Artemis presumes that whatever happened in the past cannot be changed. It turns out he's right. It also lets a huge variety of crazy actions take place.
    • Strangely, the previous book in the series, The Lost Colony, completely averts this trope in favor of shooting hoops with the Timey-Wimey Ball. Artemis manages to bring multiple people Back from the Dead by firing a stun-gun into the recent past, although it may be justified with the fact that time was currently going bonkers.
  • In Aunt Maria, by Diana Wynne Jones, the main characters go back in time in the form of cats to stop Anthony from being imprisoned underground. He ends up tripping over them and falling into the trap.
    • Technically they were only trying to figure out where he'd been buried. The protagonist's mother happened to be a bit stupid though, and tried to save him.
  • Happens quite a lot in Count and Countess, in which the two eponymous characters exchange letters with each other despite living more than a hundred years apart. Notably, Elizabeth, living in the 1500s, knows that her ancestor Matyas Hunyadi (in the 1400s) held the throne of Hungary for a very long time. In an attempt to save Vlad Dracula's life, she warns him not to try to make a grab for the throne, or he will probably be killed. As a result, Vlad stays as far away from Hunyadi as possible. Which gives Hunyadi plenty of time to rouse the Black Forces against Vlad and stop him in his tracks.
  • The Dandelion Girl, a short story by Robert F. Young; the trope specifically applies to Julie. In the end, it is revealed that Anne and Julie are actually one and the same person; Anne/Julie's real name is probably Julianne. And so Mark has always been married to the same girl-from-the-future all along, as "Julie" had traveled further back in time to meet him in his 20's.
  • Dragonriders of Pern:
    • In Dragonflight, F'nor returns from the past to warn his friends that an expedition they're planning is going to fail. Unfortunately they now know that if they don't go it'll create a paradox because the guy who warned them won't come back in time to warn them... so his warning has exactly the opposite effect. Knowing they're going to fail they have to set out anyway.
    • And of course we have the situation where there are too few riders in the present due to many of them having suddenly disappeared in the past. So someone travels into the past to gather some more, thus causing the shortage. (Although it's not as futile as it sounds because their numbers would have declined anyway due to a coming period of long inactivity. This way their disappearance is useful.)
      • This is without even mentioning events from a more recent novel in which a Gold somehow randomly jumps to a few centuries in the past after being given a BAD mixture of gene-altering medicines in an effort to cure a plague running through the dragons themselves, which results in said Gold crash-landing in a time when one of the last trained geneticists is still alive, thereby resulting in the creation of aforementioned medicines when they would not have otherwise been made, but had already been made anyway because in the past the sick dragon had already crashed....good god my head hurts.
      • And even THAT ties back to the original trilogy of books by establishing, at long last, just what the 'Ancient-timers' room was made for, and what the colorful diagrams REALLY were.
    • Also noteworthy is the climax of All the Weyrs of Pern, where the AIVAS reveals to Jaxom that two of the three antimatter charges used to divert the Red Star from its orbit have to be placed in the past in order to have the proper effect, and that those past explosions are what caused the so-called Long Intervals in which Thread did not fall. Of course, if those hadn't occurred, none of the events of those books would have occurred either, including the discovery of the AIVAS itself.
  • The climax of Harry Potter and the Prisoner of Azkaban. Harry and Hermione (Ron is in the Hospital Wing with a broken leg) go to the past to save Buckbeak and Sirius, but the method of time travel used has this trope in full force, plus Never Shall The Selves Meet. Harry breaks the Never Shall The Selves Meet rule to save himself from a Dementor, but avoids consequences because his past self barely saw him and thought it was his father, who he strongly resembles. He also later explains his first perfect Patronus as knowing that he could do it because he'd already done it from his past self's perspective (once he figured out who it was he saw). They manage to save Buckbeak despite supposedly hearing him be executed (the executioner actually realized he was missing and swung his axe at a fencepost in frustration), and use him to get Sirius to safety after he's imprisoned in the castle.
  • Used extensively in Haruhi Suzumiya this seems to be the whole purpose of future(er) Asahina. Who is suspected to be the superior of Present(or rather not-so-future) Asahina, and puts her younger self through all the missions and trouble she already went through herself. So she already changed the past because she will order herself to go to the past and change it so she can get to the future and order herself to change the past.
  • Douglas Adams' The Hitchhiker's Guide to the Galaxy universe works this way. In the second book, The Restaurant at the End of the Universe, while stranded on prehistoric Earth with an exodus' worth of incompetent aliens who are plainly going to begin colonizing, Ford Prefect tells Arthur Dent "This doesn't change the past, this is the past."
    • Then again, Ford and Arthur's presence in the past is almost completely negligible. For example, they simply show up in the alien ship. It was already supposed to crash on Earth and they had nothing to do with that.
  • In INVADERS of the ROKUJYOUMA!?, Koutarou and Clan are accidentally displaced in time to Ancient Forthorthe when Clan attacks Koutarou for assisting her rival, Princess Theiamillis of the Forthorthian Galactic Empire. There, they become involved in the foundational myth of Forthorthe, with Koutarou wearing a suit of powered armor borrowed from Theia. Clan eventually realizes, after curing a then-incurable disease with advanced technology, that the historical story was only possible through their intervention, with many of the fantastical elements of the myth supplied by Koutarou's powered armor.
    • In fact, they were originally thrown out of time and encountered the goddess of the setting, who was inspired to create the entire universe based on learning about Koutarou.
  • In Jago, one of the protagonists is temporarily transported to the past by the Reality Warper power of the villain, Jago, and rushes out a brief and unintentionally cryptic warning about Jago before being transported away again. The main effect of the warning is that it is overheard by a Jago ancestor in that time period, planting seeds of paranoia that warp the Jago family's path and result in the present-day Jago being the person he is.
  • Joel Suzuki: In Fable of the Fatewave, Joel and Felicity go back to the time of the Fourfoot War in order to prevent Blackspore from bringing Marshall Byle over to help with the war in order to save all the people Marshall killed. They overshoot their destination and end up shortly before the start of the war. Joel's presence ends up causing the war - Chief Fourfoot falls in love with him and orders him to marry him, and Joel refuses. Island law allows someone from outside a chief's village to refuse marriage to a chief, and Fourfoot can't change that law without the agreement of the other three village chiefs, so he declares was on the other three villages in order to become sole chief so he can force whomever he wants to marry him. Later, Joel and Felicity manage to talk Blackspore out of bringing Marshall over, but just as the timeline is starting to change, Thornleaf knocks out Joel, Felicity, and Blackspore and finishes the incantation himself because he doesn't believe in messing with the timeline.
  • This is how most of the wizards decide time travel works in The Last Continent ("In fact, history depends on you treading on the ants you've already trodden on.") There's no real evidence they're right, but it's simpler than Stibbons attempting to explain the Butterfly of Doom. It does seem to apply in Fourecks, where Scrappy tells Rincewind that things he's going to do will affect the past, but in Fourecks the Timey-Wimey Ball is in full effect.
  • The Licanius Trilogy: Since this work deals heavily in themes of fate, predestination, and free will, this trope comes up a lot. Perhaps the biggest example is when Caeden begs El for the chance to go back in time and prevent Davian's fated death, only to realize at the absolute last moment that it was Caeden himself, shapeshifted to look like Davian, who was fated to die from the beginning.
  • This is how Time Travel might work in Magic 2.0, at least, as far as they know. Nothing seems to change the future, past a certain point. For instance, time travelers who went to live out Arabian Nights caused medieval England to have glass windows, but the future is unchanged. Shown in more detail in the second book, where two of the same person are there at the same time, and the older one insists on this trope. Then again, since all of reality is a complex computer program, "time travel" is being played out in accordance with the program's logic. Time travelers are specifically forbidden from going to their own future, implying it doesn't exist yet, even though they know people who have come from a later date. Some theorize that traveling to the past results in the program merely creating a separate version of reality (i.e. a separate virtual world), in which they can do whatever they want without affecting their original "world".
    • Interestingly, in the case of the same person existing in a Stable Time Loop with herself, all the predictions of her older self turn out to be spot-on, and any even where it seems things will work out differently are actually orchestrated by her to make it seem this way.
    • Good luck convincing Phillip of that, though. He rejects any idea that his fate is not his to control, which is what first endears him to Brit the Younger (who has been forced to live alongside her older self Brit the Elder for decades, constantly being looked down upon as an immature child). Phillip posits that Brit the Elder is merely a construct of the program, created to maintain the illusion of a Stable Time Loop and that she's not really the future version of Brit the Younger.
  • Greg Egan plays with this trope every which way from Sunday (except straight) in his Orthogonal trilogy — mostly just because everybody accepts that it would be impossible to change the past, so nobody tries.
    • Discussed: As mentioned on the main bullet above, as soon as the characters nail down the nature of spacetime, it's pretty much accepted that Time Travel, while possible (and surprisingly easy), cannot actually change anything.
    • Double (Triple?) Subversion: On Esilio, a planet with Merlin Sickness, the crew of the Surveyor blow up a rock. After the explosion, they find what looks like writing etched into a newly-exposed part of the rock, which seems to be a message from the ancestors (the inhabitants of the homeworld). Because of the planet's Merlin Sickness, the message must have been carved at some point in the future. The obvious assumption is that the message means the journey is successful; the Peerless makes it home, and at some point the ancestors visit Esilio and carve the message as encouragement to the travelers. But Ramiro decides that he wants to have a hand in fate, so he plans to go out and "carve" the message himself. Tarquinia prevents him from doing so — and he then realizes that she is going to carve the message. He spends most of the rest of the book under the impression that she did — only to discover after the climax that she tried to carve it, but no matter what she tried, the message stayed there, which means that she didn't do it either. The book ends with an implication that one of the characters who returns to the homeworld in the epilogue is the one to go to Esilio and carve the message.
    • Invoked: The Surveyor returns to the Peerless after a long absence to find that the inverted Time Capsule messaging system (which essentially lets people send email back in time) has been built, but also mysteriously stops working all at once at a known point in the future. But since no one actually knows what causes the disruption, the crew of the Surveyor realize that if nobody does anything, they are most likely consigning themselves to being hit by a meteor. On the other hand, if they attempt to sabotage the system, they are raising the probability that they will cause the disruption, which means no one will be harmed. In other words, they know they Can't Fight Fate since the universe is an absolutely Stable Time Loop, but if nobody tries to cause the disruption, then it's almost guaranteed that it's caused by a disaster such as a meteor strike; but as long as no one knows what causes the disruption and someone is trying to cause it, they are increasing the odds that the disruption has a harmless cause. Yeah.
  • The Skull by Philip K. Dick. An assassin is sent back in time to kill the founder of a subversive religion before he gives a famous speech, only to realize that the Founder is himself — the 'miracle' that inspired the religion's creation was him appearing after he'd been killed (he'd arrived at the wrong point in time) thus 'coming back from the dead'. The Rousing Speech supposedly given by the Founder never actually happened, but was a result of history being embellished after his death. All he said was:
    "I have an odd paradox for you. Those who take lives will lose their own. Those who kill, will die. But he who gives his own life away will live again!"
  • Minor example in So You Want To Be A Wizard by Diane Duane: Nita and Kit are stopped for a moment on their way to a world gate by a loud bang on the other side of a door they are about to open. It turns out at the end of the book that it was Nita herself, coming back from the future a little earlier than planned and trying to avoid meeting their younger selves.
  • There Will Be Time by Poul Anderson. A substantial number of humans have had the innate ability to Time Travel since before recorded history (possibly because it was inserted into the genome by future travelers). So little of human history is known exactly, and the book's scope is so great (from Jesus' crucifixion to a far-future postapocalyptic revival of civilization—at least) that the inability to change the past comes up only rarely—but the protagonist is nearly broken when his Byzantine wife dies of an illness because other travelers have abducted him to the future.
    • It is established fairly early in the story that it is impossible to change anything that the hero knows about what will happen. Every attempt he makes to save his father (who died in WW-II) is prevented in some way.
  • This was true in the novel The Time Traveler's Wife by Audrey Niffenegger. The main character was constantly going into both the past and future, but everything was pre-set. Everything he did when he went into the past, he had "already done", and once something happened, he could never change it; in situations where he already knew what was going to happen, he had to act in the way he had already acted, he didn't have any choice.
  • Unborn Tomorrow, a short story by Mack Reynolds. An Eccentric Millionaire wants a private eye to locate a time traveler from the future and get the secret of eternal life. He believes such time travelers would go to the Oktoberfest, where everyone would be too drunk to notice anything strange about them. The private eye's secretary is surprised when her boss curtly turns down this chance to get drunk on someone else's money. The private eye explains that he's already taken the assignment three times, and each time the time travelers sent him back to this point in the time line, with a massive hangover from drinking too much German beer. There's no way he's getting another hangover piled on top of the previous three, not for any amount of money!
  • In Robin Jarvis' The Woven Path, the spirit of an American airman has waited decades for his chance to return to World War II-era London and prevent the deaths of his loved ones (and himself). When the Fates finally give him this opportunity, he is outraged when things turn out almost exactly as they did before in spite of his efforts. They explain to him that they knew all along that his path was already woven and could not be changed; they just failed to tell him that in the first place.

    Live-Action TV 
  • Early seasons of Andromeda used this, but it degenerated into Timey-Wimey Ball territory after a while, to the point where an entire episode is devoted to showing how things originally went before being changed (specifically, Gaheris Rhade kills Dylan in the original timeline and ends up in the Bad Future. Disillusioned with his own people, he resolves to re-create the Commonwealth, but his prejudices and lack of compassion keep him from being successful. As everything is going to hell, he goes back in time, kills his past self, and throws the fight with Dylan in order to ensure that Dylan is the one who ends up in the Bad Future).
  • The only time-travel arc on Babylon 5 involves this trope, and it is absolutely central to both the Myth Arc and the background mythology of the show. Babylon 4 appears in Babylon 5 space four years after it disappears (the episode "Babylon Squared". The events leading up to that appearance are explained in the two-parter "War Without End, Part 1 & 2", in which we find out that Babylon 4 was taken to the year 1260 AD (or so) to help the Minbari and their allies gather to fight the Shadows. To prevent this from happening, the Shadows sent a big bomb to Babylon 4 just as it was about to come online in 2254. However, the White Star also goes back in time (because Delenn, Sinclair, Sheridan, and Ivanova see it in a recording), destroys the bomb, and (as it turns out) takes it back in time as well. However, this is not before the time device (sent by Draal and transported by Zathras) malfunctions, dropping Babylon 4 into 2258, leading to the events of "Babylon Squared." Sinclair then realizes (having received a message from Valen before the journey) that he must take Babylon 4 back in time himself, and then uses the triluminary device to turn himself into a Minbari—specifically, Valen, who led them in the First Shadow War, organized their society, and effectively became the main prophet of their religion. The Stable Time Loop is fully completed, so to speak, by the fact that when Valen dies, he eventually gets reincarnated as Sinclair.
    • Valen/Sinclair doesn't need to be reincarnated. From his point of view, he is born in the 23rd century as a human, goes through the War and subsequent events of the series up to "War Without End" and then goes back in time to the 13th century as a Minbari and lives out his life as Valen. The Minbari think he is Valen reincarnated when they encounter him at the Battle of the Line because he has Valen's soul; not knowing about the time travel, they don't see that Sinclair will become Valen in the future before travelling back to the past.
    • Additionally, during the Battle of the Line, Delenn wants to bring in a human prisoner to study, so she picks a Starfury about to ram their warcruiser, which happens to be piloted by Sinclair. She later finds out that she's a direct descendant of Valen, who is Sinclair's future self (in the past). Thus, Delenn inadvertently saves her great-great-great-something-grandfather, which would eventually allow her to be born.
    • There are some odd things involving Babylon 4, namely Sinclair getting visions of a Bad Future, in which his friends are killed and the Babylon 5 station is destroyed during a battle. That future never comes to pass, although it's possible he simply misinterpreted the vision (his friends don't actually die, and the station is destroyed in the future, but it's actually decommissioned and scuttled). Word of God is that the visions are what would have happened if he had not traveled back in time.
  • Doctor Who has, unsurprisingly, used this one multiple times (as with most time travel theories):
    • "Day of the Daleks": freedom fighters from a Dalek-dominated Dark Future come back to the UNIT era to kill the diplomat they believe incited a nuclear war, but it turns out that they were responsible for the terrorist bomb that started the conflict. Fortunately, the Doctor is able to talk down the bomb-carrier and break them out of their Stable Time Loop.
    • "Blink": "You're reading aloud from a transcript of a conversation you're still having?"
    • In "The Fires of Pompeii", the Doctor doesn't want to avert the destruction of Pompeii, is convinced to avert it anyway, and then is forced to cause the disaster in order to avert a larger catastrophe.
    • The TARDIS explosion in "The Pandorica Opens"/"The Big Bang" was successfully prevented (in a fairly static timeline, probably) with the help of River Song, who wouldn't exist until a series of events that could only have happened after (?) it. Adding to the temporal weirdness which comes with this is the fact that she was around to see a crack in "Flesh and Stone", even though, from her perspective, the cracks never existed (or maybe they did, but she had just played a direct role in making sure they were completely erased from the universe). Every encounter with River can basically be summed up as "an inexplicably Stable Time Loop".
    • Another one related to the TARDIS explosion. It's revealed in "The Time of the Doctor" that those responsible were a splinter group of the Silence, who had traveled back in time to kill the Doctor in order to prevent him reaching Trenzalore, where the Time Lords were preparing to return to the universe through a crack in time after having the Doctor confirm his name to them. The explosion of the TARDIS is what caused the cracks to begin with.
    • It becomes especially common beginning with the Steven Moffat era, where he cracks down on all the "Why don't they just go back and..." questions that plague any Time Travel story by saying that you can't alter events you're part of or have even witnessed or learned about without causing a Time Crash (presumably for the reason mentioned early in this page description: if Bob saves Alice, Alice never died, so Alice never needed saving... so Bob never saved Alice, so she did need saving, so he did save her, so she didn't need saving... there's just no answer for what the moment after Bob's little time trip would look like. Trying is a good way to break time itself.) However, such events have been thwarted anyway through tricky manipulation of events, ending in "what you saw in the future was unchanged, but it never meant what you thought it meant." To go back to the example at the start of the page, by Moffat's rules, if Bob goes back to save Alice, and then the Killer Robot chasing them eventually disguises itself as Alice and gets disposed of in the ensuing battle by being shoved in front of the very truck that Past Bob saw hitting "Alice" in his vision of the future, the space-time continuum and Alice will be just fine. Cue a Once More, with Clarity scene with Alice's "death" shown from another angle, and Past Bob running off to fire up his time machine and failing to notice the sparks coming from "Alice" just as he turns his back, while Future Bob and Alice hide and go unnoticed.
  • Inverted in Farscape. Sent back in time and desperate to keep things the way they were, the crew screws up, with each attempt to force what they know to be history resulting in the present time line getting worse. In the end, rather than the noncombatant survivors of the battle being spared in a hasty but well-regarded treaty, they are butchered by enraged enemy soldiers. The memorial to peace becomes a lament of the senseless slaughter.
    • A later episode plays this trope much straighter, with strong hints that certain events from John's childhood were always caused by his future self and Moya's crew accidentally traveling back in time to 1985.
  • How Hodor got his name in Game of Thrones. Lampshaded by the Three-Eyed Raven telling Bran "the ink is dry" on the past should he desire to change it.
  • In the Haven episode "Sarah", Duke is sent back in time to the point when his grandfather Roy was killed, and decides to try and avert this. Instead he accidentally tips the guy off that he's about to be killed and by whom, sending Roy racing off to start the shootout that ends in his death.
  • In the Hercules: The Legendary Journeys two part adventure "Armageddon Now", Callisto goes back in time to prevent who she thinks was Xena (because her army was in the village) from killing her parents. While trying to protect her family from Xena's army, the adult Callisto accidentally kills her own father and is forced to kill her mother after realizing that she can't change anything. She then tries to burn her younger self alive, either wishing to break the loop or remembering herself being rescued from a fire.
  • Legion: In "Chapter 22", David Haller's plan when he travels back in time is to protect his baby self from being possessed by the disembodied Amahl Farouk, but David's presence ends up facilitating the infection. David's attempt at communicating with his mother Gabrielle causes her to faint, and then his father Charles Xavier arrives home from Morocco to find his wife unconscious on the floor. Charles assumes that the ghostly apparition (who is the adult David, but Charles doesn't know that) in his infant son's bedroom is the culprit, so Charles hurls the intruder away with his Psychic Powers. While Charles is distracted trying to revive Gabrielle, he doesn't notice that behind him, Farouk's consciousness is entering baby David's mind. The adult David's interference in the past sealed his own fate.
  • This concept became a major plot point in the fifth season of Lost (which Hurley couldn't quite grasp) though it was put to the test in the cliffhanger finale...
    • Particularly annoying with Sayid shooting young Ben, which was not only implied to have already happened, Kate and Sawyer's interference in order to put things right seems to actually have caused Ben to become evil, as Richard says that because the island healed him he would always be "one of them" and that he would "lose his innocence". So by trying to kill him, they effectively caused what they were trying to prevent. Nice going, guys!
  • In the season 1 finale of The Ministry of Time, Julián travels back to 2012 to try to save his wife, only to end up indirectly triggering the car crash in which she died.
  • In the Murder Most Horrid episode "A Determined Woman", a female scientist working on a time machine becomes so frustrated with her idiot husband's antics that she kills him. Several years later she is released from prison, finishes her time machine and goes back to try and save her husband, only to find that his confusion between the two versions of her is what caused his erratic behavior in the first place.
  • In the Mystery Science Theater 3000 episode "Hobgoblins", Tom Servo tries to go back in time to stop the movie from being made by hunting down the director and... kicking him in the shin. Upon Tom's return to his present, Crow pulls up an article in which the director claimed that his inspiration for Hobgoblins was that time when a squat red robot ran up to him out of the blue and kicked him in the shin...
  • The Outer Limits (1995): This is a recurring theme in the time travel episodes of the Nicholas Prentice arc.
    • In the episode "Tribunal", history professor and Holocaust scholar Aaron Zgierski is taken back to Auschwitz by time-traveler Nicholas Prentice (who turns out to be Zgierski's own great-grandson). While there, they rescue Aaron's "older" sister (who is only eight at the time) by bringing her into the future to live out her life free of Nazi oppression. History recorded Aaron's sister as dying at Auschwitz after being "dragged away" by a couple of guards, who were actually Zgierski and Prentice in disguise.
    • "Breaking Point" involves a scientist building a time machine and traveling several days into the future, where he sees his wife bleeding out from a gunshot wound in their living room. Distraught, he goes back and does his best to prevent this from happening. Not only does he sound crazy to everyone around him (including his wife), but his time travel has also unhinged him, slowly driving him crazy for real, until he accidentally shoots his wife with the gun he got to save her from being shot. The episode then promptly subverts this by having him go back to the day he first met his wife and killing his younger self before the event, himself vanishing due to the Grandfather Paradox. Then we're shown his future wife, who appears to be depressed and preparing to commit suicide (it's implied that meeting him would have helped get through the depression).
    • In "Gettysburg", Prentice wants to change the past by convincing a Civil War buff (who has pro-Confederate views) of the wrongness of his convictions by taking him and his friend to just before the Battle of Gettysburg. Originally, the buff was going to assassinate a black President in his own future. Instead, the buff takes this opportunity to try to alter the course of the battle in the Confederate favor. He accidentally uses Prentice's time machine (shaped as an old-fashioned camera) to transport a Confederate general through time. His attempts at preventing the (from his viewpoint) catastrophe result in him getting shot for cowardice. Prentice takes the friend back to his time, and the latter finds an old newspaper with the picture of his dead friend. Meanwhile, in the Future… the transported Confederate general appears at the moment of the original assassination, and he ends up being the presidential assassin (he was actually aiming for a man dressed as Abraham Lincoln, who was standing next to the president).
    • "Time to Time" subverts this when a new recruit into the temporal agency goes back in time and prevents her father's death due to eco-terrorists' bomb going off prematurely. This results in another member of the agency suddenly vanishing. His colleagues figured out that, without her father to tamper with the bomb, it went off as planned and killed a lot of innocent people, including an ancestor of the temporal agent who disappeared. Reluctantly, the girl has to let her father sacrifice himself. However, she does alter her mother's fate somewhat by giving her a coping mechanism (in her timeline, her mother's a wreck; in the altered one, she is an accomplished artist).
  • Quantum Leap was somewhat inconsistent on this trope. It's the trope namer for Set Right What Once Went Wrong, but Sam and Al always remember how things used-to-be even as Sam changes the past (Al keeps track of the current timeline's history using his handheld computer-link to Mission Control). In episodes that directly impacted Al or Sam, they would have the entire memory of both things happening.
    • Sam successfully tries to save his brother's life in Vietnam, which alters history and results in Al still becoming a prisoner of war. Al allowed him to save his brother by not telling him he was one of the prisoners.
    • The series finale had a somewhat omniscient bartender asking Sam if there was anything that he wanted to do differently. Sam remembers when Al was invisibly dancing with his first wife, Beth, who became heartbroken when she thought Al was killed in Vietnam and married someone else by the time Al was released. Sam then travels to that moment and tells Beth that Al is alive and coming home - the next leap only shows a black screen, with epilogue text stating that Al and Beth had celebrated their 39th anniversary and Sam was never seen again. Supposedly, this is an example of Executive Meddling, since the creators did not expect the show to be over at this point. When the news came about the show's cancellation, they hastily added a blank screen (so hastily they misspelled Sam's last name) as a half-assed attempt to wrap up the show.
    • In one episode, Congress is reviewing Project Quantum Leap's funding and leans on Al (acting as the project's representative) to have Sam alter history in ways beneficial to the US. Al tries to get Sam to prevent the U-2 spy plane incident, but Sam is in the past protecting a young attorney. At the end of the episode, the Congressman in charge of the committee is about to cut the project's funding when, in the past, Sam unintentionally corrects the attorney on a key piece of Constitutional law which she had wrong and she says could have made her fail the bar. Cut to the present, where the obstructionist Congressman is replaced by an older version of the attorney, who approves the project's funding for another year. It's never made explicit, but Al's surprise at the sudden change suggests that he's aware of the change.
    • However, in the episode about the Kennedy assassination, while Sam can't prevent himself from killing JFK, it then appears the reason he was sent back there was to prevent Jackie Kennedy from being killed, which most viewers would have assumed had already happened, whether Sam had anything to do with it or not.
  • The first Time Travel episode of Stargate SG-1 ("1969") can be perceived as following this logic, but none of the subsequent Time Travel episodes in the Stargate-verse can — they all involve alternate timelines instead.
    • Though it seems SG-1 held to the "Alternate timelines/universes" first. The 20th episode of Season 1 had the "Quantum Mirror" which put Daniel Jackson in an alternate timeline/universe. "1969" was the 21st episode of Season 2.
    • Stargate: Continuum shows the present universe being erased by Baal's actions in the past. As a part of the SG-1 team consciously try to outrun the phenomenon, the stargate wormhole somehow shields them from it. So, while there are alternate realities in the Stargate-verse, those may be unrelated to time travel. Either that, or the writers just can't decide.
  • The Star Trek: The Original Series episode "Assignment: Earth" ends with the reveal that the Enterprise's historical records show that a malfunctioning nuclear platform exploded just as it did in the episode, indicating that Gary Seven's mission (complete with Kirk and Spock's interference therewith) was part of their existing timeline.
    • This actually ended up being shockingly accurate to the viewer's timeline. The episode tells us they're visiting the year 1968, and Spock indicates that on the day in question, there will be an important assassination and that the US will launch an orbital weapons platform (the latter of which becomes the basis of the episode's plot). On March 4th, 1968, six days after the episode aired, Dr. Martin Luther King, Jr., was assassinated, and the US launched Apollo 6, which crashed...the same fate as the unnamed platform at the center of the episode
  • Conspicuously averted in Star Trek: Deep Space Nine episode "Trials and Tribble-ations":
    Temporal Investigator Dulmur: Captain, why did you take the Defiant back in time?
    Sisko: It was an accident.
    Temporal Investigator Lucsly: So you're not contending it was a predestination paradox?
    Dulmur: A time loop. That you were meant to go back into the past?
    Sisko: No, we're not.
    Dulmur: Good.
    Lucsly: We hate those.
    • Bashir does suggest this as a possibility at one point during the episode, though he turns out to be incorrect (presumably, anyway, since the timeline wasn't altered by the "predestined" event being unfulfilled). Luckily, the investigators weren't around to hear him.
  • Heartbreakingly (how else?) done in Supernatural when Dean is sent back in time to 1973 and meets his father. He decides to kill the Yellow Eyed Demon that killed his mother, poisoned his brother and set his family on a decades long revenge quest, before it ever comes near his family. Unfortunately, his efforts to kill the YED is what attracts it to his mother who is manipulated into making a deal with the YED, thus dooming his family.
  • In Terminator: The Sarah Connor Chronicles episode "Allison from Palmdale", Cameron malfunctions and believes herself to be Allison Young, the resistance fighter on whom her appearance was based. She calls "her" mother, who says this must be some mistake since she doesn't have a daughter "yet"...
    Claire Young: [rubbing her pregnant belly] That's a beautiful name though. "Allison"...
    • Given how time travel appears to work in this universenote , however, it's probably that Allison's mother would have chosen that name anyway.
  • The Twilight Zone:
    • The Twilight Zone (1959):
      • Subverted in the second season episode "Back There", in which a young engineer has a discussion with his fellow rich friends about this topic. He then finds himself back in time to the night of Abraham Lincoln's assassination. He desperately tries to warn everyone that Lincoln will be assassinated, but he's brushed off as drunk and a man named Wellington (who late turns out to be John Wilkes Booth) takes him in. While in his care Wellington drugs him and goes to assassinate Lincoln. When the engineer wakes up, the president is shot mere moments later and he discovers the man who drugged him was in fact John Wilkes Booth. When he goes back to his original timeline, he discovers he did actually change one thing. The police officer who believed him and tried to save the president got promoted to chief of police then a councilman and later became a millionaire allowing his descendant (who in the original timeline was an attendant at club the engineer was a part of) to inherit his fortune.
      • Played straight in "No Time Like the Past", in which after a scientist fails several times to change history, he decides to go back to a time where there were no issues, 1888. Upon realizing there will be a fire at the school, so he tries to stop it, but when a horse and buggy swerves to avoid hitting him, it launches a lantern which hits the school causing the aforementioned fire.
    • In the The Twilight Zone (1985) episode "Profile in Silver", a time travelling historian saves his ancestor John F. Kennedy from being assassinated. The resulting damage to space time then creates a timeline where World War III and the extinction of humanity is inevitable. Kennedy volunteers to go back to set things right but the historian instead sends Kennedy to the future and takes Kennedy's place in the motorcade, being assassinated in his place. A colleague of the historian then tells the Secret Service agent who helped him that "Even the act of traveling in time is part of history" and that the historian's sacrifice was part of the "correct" timeline.
    • In the The Twilight Zone (2002) episode "Cradle of Darkness", a young woman (played by Katherine Heigl) is one of the few people capable of surviving time travel. She agrees to take a one-way trip to the past to kill Hitler as a baby (it's not clear why the future people think that the new reality will be better). She pretends to be a new maid and ingrains herself into the Hitler family, realizing that Hitler Sr. is the one who taught his son to hate the "lesser races". In the end, she grabs the baby and jumps into the river (also unexplained why she had to jump herself, possibly guilt for killing an as-yet-innocent baby, though it was mentioned in the beginning it was a one way trip so it's not like she could get back to her original timeline). The other maid, takes a homeless gypsy's baby and passes it off as young Adolf. So yeah, if this is believed, Hitler was one of the "lesser races" he hated so much.

  • The Black Sabbath song "Iron Man".note  A guy goes forward in time and winds up After the End, where the world has been destroyed by some weird metallic monstrosity. He tries to come back and change it, but the change turns him into the weird metallic monstrosity and he is mocked and ridiculed by society. So he destroys the world.
  • In Ludo's rock opera "The Broken Bride" the narrator builds a time machine to go back and save his wife/girlfriend who had died in a car wreck. After fighting dinosaurs in the past and a zombie apocalypse in the future, he makes it back to his own time, only to find that the same events are occurring as they did before. Instead of saving his girlfriend/wife, he decides to go along for the ride. One can assume they both die, this time.
  • Stereophonics: In the music video for "A Thousand Trees", a man sees his partner being hugged by a stranger. He assumes this means she is having an affair (though he should have wondered why she was so open about it when near enough to their house). He storms out after she gets back, and in the ensuing row on the street steps into the road as a car is going past, running him over - with the driver being the stranger from earlier, who then comforts his now distraught girlfriend - via the hug seen earlier. And all this for a music track that is seemingly about a report of sexual abuse by a girl against a man (the 'match that burned a thousand trees').

    Myths & Religion 
  • As mentioned, Greek and Germanic mythology tended to hammer on the idea (relying on prophecies instead of time travel) that You Cannot Change The Future. Even the Gods can't change the outcome of the story. (How many steps is Thor destined to take in the final battle of Ragnarok?) Not only that, but historians actually posit that Norse culture went into a prolonged funk over it, presaging the rise of Ingmar Bergman and Werner Herzog by centuries. (The lack of sunlight in wintertime didn't help.) Norsemen in particular lamented the decline in pagan beliefs for exposing them to the horrors of existentialism, making them less resigned to the inevitability of death in battle. Meanwhile, the Greeks preferred to set up stories where characters would have hubris enough to believe this trope did not apply to them, and then brutally swat them down in order to provide an entertaining Aesop. For examples, see You Can't Fight Fate and Self-Fulfilling Prophecy.
    • There are some indications Germanic mythology played with this, however, in that while one couldn't alter their own fate, because the fates of all beings are intertwined with one another, everyone else's actions can affect another's fate.
  • The concept of Predestination. This concept is prevalent in all Calvinist churches (Reformed, Presbyterian, Baptist, congregational, Pentecostal), and in nutshell means that the life and final depository of a human being is preordained and predetermined by God and he or she can do nothing to avoid it. In other words, people are selected either to Heaven or Hell before they even were born.
    • This same concept is prevalent in Islam. The only way to avert the predestination is to get killed in Holy War, which earns you an automatic admission to Paradise. However, most Muslims believe that Allah only sees what people will do ahead of time, but doesn't cause it (whether or not that really allows for free will can be debated of course).

    Tabletop Games 
  • C°ntinuum: roleplaying in The Yet: It's an ironclad article of Spanner faith that there is only one universe — including one past and one future. A player will meet fellow spanners who've been affected by changes that are in the player's Yet, and you'd better do them or risk Frag.
  • In Transdimensional Teenage Mutant Ninja Turtles, the GM was to have an important recurring character recognize the characters in a future era even if they hadn't met him yet in a past one.
  • Warhammer Fantasy Roleplay: The Celestial Order of wizards, who specialize in astrology and reading the future, select their leaders through ontological paradox — they appoint the person they foresee being appointed. The question of what force actually determines who gets appointed keeps the current leader awake at night.

  • At the end of A Very Potter Sequel Hermione asks future!Draco what was really supposed to happen during their first year and Draco says that this was how it all played out originally, it just makes sense now that he lived through it.

    Theme Parks 
  • Featured in one of the videos leading into The Simpsons Ride at Universal Studios. Professor Frink arrives looking for Doc Brown's Institute of Future Technology, only to find it replaced by a clownish theme park (Krustyland). He decides to stop it by going "back to the future, I mean past." He gets into a Delorean and accelerates into a time jump. Two years ago, a broker is telling Doc Brown that he'll be able to keep the Institute open for years to come. At that point, the Delorean materializes and runs over the broker. Frink jumps out and Brown yells at him "You ruined everything! Now I'll have to sell the Institute of Future Technology to that mercenary clown!" Krusty promptly pastes a Krustyland logo over the IFT logo on the front sign.
    • Brown then shows Krusty to his limo, and Krusty tells him to tear tickets at the front gate after he gets a haircut.

    Video Games 
  • Braid features this when you try to rescue the princess - and then see that she was running away from you instead...
  • In Crash Bandicoot 4: It's About Time, the final dimension is set on Cortex's island just before the events of the original Crash Bandicoot, with Cortex trying to stop his past self from creating Crash... Only for his defeat to inspire his past self to turn Crash into his General, and Crash himself breaking something very important which made sure that he became the bandicoot he is today. Coco lampshades this with a simple, "Explains a lot," once she sees this happen.
  • The ending of Final Fantasy VIII has this trope, with Ultimecia giving her sorceress powers to Edea in the past and Squall suggesting the SeeD idea at the same moment, setting up the organization that Squall is raised by.
  • A Double Subversion occurs at the very end of Futurama: The Game. Farnsworth learns from his own crew-from-the-future that Mom's imminent purchase of Planet Express will lead to her taking over the Universe, and says the deal's off. Mom tells him that it is destined to occur anyway, because "No one can alter the continuum of time!" Farnsworth replies "Oh yeah? Watch me!" and tears up the contract. Then Mom sweetens the deal by offering him a hat... the very same hat he had entered the room wearing at the beginning of the game.
  • The Journeyman Project seems to avert this; when the past is changed, it sends a measurable 'ripple effect' back up the time stream, which can be detected and is used to alert time agents to Set Right What Once Went Wrong. However, it's theorized that there are some changes to the timeline that are actually supposed to happen, which don't produce these ripples and thus can't be detected and averted. These include your attempts to correct the other changes, which is why the alternate universe counterparts of your Time Police organization aren't ever seen to try and stop you. At least, except when they physically catch you wandering around their base.
  • The Legacy of Kain series uses this as an important plot point; more than one character has goals achievable only by finding ways to subvert this. Interestingly, while two entire games in the series take place in the past, while this trope is in effect, it still manages to have one of the most complicated sets of Gambit Roulette ever. One of the protagonists is himself a walking subversion, and thus finds himself endlessly manipulated by pretty much everyone, because he's the only one who can alter time in their favor.
    Kain: "Suppose you flip a coin enough times. Suppose one lands on its edge."
    • Interestingly the first game in the series, Blood Omen, used a different kind of time travel - the kind where you go back, do something, and return to the present to find the effects of your actions having taken place. This was played straight with no mention of the paradox that would ensue from this kind of time travel. Two games later, in Soul Reaver 2, when time travel was reintroduced as a much more significant plot element, the rules were established around this instance of time travel, and it turns out Kain's original trip back to the past, as depicted in the first game without RetCons, already met the criteria for how someone can achieve a true alteration to the time line.
  • In Ōkami, the evil Orochi was defeated by a legendary hero named Nagi and a miraculous white wolf, who died in the attempt. The wolf was actually Amaterasu in physical guise, and was resurrected a century later as you, the player character. But then you travel back in time and discover — you were the one who defeated Orochi then too, and the wolf who died was a different version of you.
  • In Pokémon HeartGold and SoulSilver, it's revealed that the reason Giovanni never returned to the revived Team Rocket is that at around the same time you were fighting Archer, your future self was sent back in time by Celebi and stopped Giovanni before he could rejoin them, ensuring he stayed retired.
  • In Prince of Persia: Warrior Within, the Prince travels to the Island of Time in hopes of preventing the Sands of Time, the source of all his misfortunes, from ever being created. He defeats the Empress of Time, only to discover that she is the sands in corporeal form, and that the events that led him here were of his own making. The second half of the game is about the Prince deciding to Screw Destiny and subvert this.
  • Played for Laughs in Sam & Max: Freelance Police, where the titular duo are stonewalled because they'd caused a mouse child to lose a treasured toy - so they travel back to the past to take the toy from him only to return it in the present.
  • Happens twice in The Silent Age: Near the end of the game the protagonist goes back to the day before the time machine pilot is due to bring the killer virus from the future only for it to become clear that his attempt ends up sabotaging the original one by accidentally shooting the scientist who tried to stop the launch, later he goes to the future to stop the time machine pilot from coming back so he doesn't cause an epidemic, only to find out the pilot doesn't make it back and the protagonist is the one who causes the outbreak. Subverted in the end when he manages to stop the outbreak anyway.
  • This is in effect for much of Singularity. The only way to break it is by traveling back in time and killing your original self before he ever gets the chance to save the Big Bad.
  • A subversion of this happens in the first installment of Spellforce. The Big Bad spends the whole game trying to get back in time to alter certain events in his favor. Once he gets back in time, it is revealed he is actually a younger version of Rohen. He then spends decades in the past, has a Heel Realization and then tries to undo the actions of an even earlier version of himself, ultimately setting in motion the events at the start of the game. What makes this a subversion is that the older version actually knows about the loop and actively maintains it to ensure his younger version performs a Heel–Face Turn.
  • TimeSplitters Future Perfect is an example of this situation. Sergeant Cortez does, at least once per time period, meet a future version of himself that saves him, then when he reaches the period the future version is from, he then goes back to save his past self, fulfilling the time loop. EX: in the stage "What Lies Below", Cortez is saved by himself from the future, then has to defend his future self from zombies while the future self kills ghosts. Shortly afterward he wants to follow his future self, but his future self tells him "but where would you be if I hadn't shown up?". Future and Past Cortez part, then Past Cortez finds the ghost gun that Future Cortez found, steps into a wormhole, and ends back up where he was before, becoming Future Cortez. Now Future Cortez (who is controlled by the player) must kill ghosts while past Cortez shoots the zombies. When past Cortez asks to stay in a team, future Cortez tells him exactly what he heard from himself at this point. "Where would you be if I hadn't shown up?". The two part, and Cortez continues.
    • This does create an odd situation however in the "Scotland the Brave" stage, where Cortez finds a locked door, and his future self gives him a key, telling him to pass it on when he's done. When he reaches this point, he finds his past self, and he gives him the key, and tells him to pass it on when he's done, then leaves. The question remains however: where did the key come from in the first place if Cortez was passing it between time periods but never stopped to find it?
    • This is explained in the final boss fight, which actually also reveals this trope was being subverted the whole time. Halfway through the fight Cortez realizes that he's outgunned and decides to go back in time and aid his past self to defeat the boss. This would be fine except that "future Cortez" never showed up to help you defeat the boss in the first place. Anya's talking of "creating a time loop" suggests that every prior instance of "looping" was caused by an alternate Cortez doing something significantly different (like say, deciding to make his Alternate Self's job easier by passing a key he found.) and only now is the player-controlled Cortez getting to be the "Starter", which also conveniently means the Player doesn't have to fight the Final Boss twice ("Past" Cortez isn't seen after the battle, because he presumably went back to help his past self battle Crow).
      • The game actually features two completely different forms of time travel, and it is implied that use of the first tore the universe a new one enabling the second.

    Visual Novels 
  • In Nine Hours, Nine Persons, Nine Doors: Akane sets up such a time loop to ensure her survival. Her future self, posing as a fellow victim of the mysterious kidnapper who set up the second Nonary game, guides her childhood friend Junpei in a way that he can psychically contact her and help her out of the room that she is still trapped in.
  • Steins;Gate: Understanding this concept is what allows Okabe (with some help from his "future" self) to turn the constant stream of Downer Endings into something much more pleasant. His early episodes boast about being "able to cheat the universe itself" doesn't look so silly anymore by the end. That said, the series doesn't follow this trope entirely with regards to time travel; it's more like a combination of For Want of a Nail and Rubber-Band History most of the time. Sending messages to the past can have fairly far-reaching implications (such as changing the actual biological sex of a person), and the butterfly effect is explicitly called out by name. However, some events have greater inevitability than others (such as Mayuri's death in the beta world line by a series of increasingly Contrived Coincidences).
  • In Umineko: When They Cry, Ange tries to Set Right What Once Went Wrong in regards to what happened on Rokkenjima in 1986. In the end, it's clear that she can't change her future; nearly everyone who was on Rokkenjima will die, Ange will still have a strained and miserable relationship with her aunt Eva, and her brother Battler will technically survive but will have undergone Death of Personality due to amnesia and will no longer consider himself her brother.

    Web Animation 
  • A three-part episode of Red vs. Blue had Church travel back in time and try to change history to prevent both his 'death' and that of Tex, as well as attempting to stop the other difficulties that the Blue Team had to encounter at the time (such as the problem with Lopez's switch, and Tucker getting blasted by an RPG). He ends up accidentally causing, or failing to prevent, every major event of the series up to that point including his own 'demise'.
    • He then wants to try again only for another version of him to tell him that it's all been tried a dozen times already by other versions of Church who all failed. Eventually, Church gives up.
    • The others experience much the same thing when they get to time-travel later on. That mysterious sniper who killed Butch Flowers the second time, after the alien revived him? That was Future Tucker. When Tucker does manage to influence the past, the consequences are bad enough that he ends up having to let the changes revert.

  • 8-Bit Theater has been explained by an in-comic character to be this, with the added You Can't Fight Fate.
    • At least, that's what the character believes. The character with enough nigh-omnipotent abilities to force things on the track he remembers.
    • Sarda did this to himself. As a young wizard, he time-traveled back to the beginning of the universe, only to find that a White Mage had gotten there first. After living through all of creation being formed around him, Sarda planned to put that White Mage into a pocket dimension before she could go back in time to the universe' start...only for that pocket dimension to be the beginning of the universe. Thus it's quite possible that Sarda came to the conclusion that time travel works this way due to his own ego: he tried to alter his own history once and it didn't that has to be because it's just not possible rather than because he personally screwed up.
      Sarda: So now I know how she got there and what it feels like when I utterly screw with someone's lifelong ambitions.
  • In The Adventures of Dr. McNinja, Chuck Goodrich is a time traveler from the future who comes to avoid The End of the World as We Know It play with this tropes. it's not like you can't change the can change how it will be The End of the World as We Know It.
    • The Adventures of Dr. McNinja does use Branching Timelines, it's just that Cumberland Is The Center Of The Universe and everything in the universe is trying to kill us. A more accurate description of the various time traveling adventures of Chuck Goodrich is that each disaster in itself acts to prevent all the other disasters that are waiting.
      • As explained by one character in a particularly nasty future, the branching timelines are the reason you can't technically change the past. See, since a future-you didn't come back in time to the present when you were taking The Slow Path to the current future, you didn't do that, so if you go back in time, you create an alternate past where you did, and the versions of your friends and family in your current future-present will never see you again, and also their lives still suck.
  • In American Barbarian, Rick's attempt to go back results in his appearing as a character already seen.
  • All the Time Travel in Bob and George eventually resolves itself into this.
  • In Homestuck, no matter what means of time travel is used, what is done, or what information is transferred, it can only result in the creation of a Stable Time Loop, or alternate timeline. Everything that happens in the Alpha timeline still happens, already including the changes from any and all time travel, before they're actually made. The Trolls regularly insist that they've already lost the game and that You Can't Fight Fate.
    • Notably, the alternate timelines created by Time players are "doomed timelines": They and anything and everything from them are marked for destruction. This can still be very useful, though, as things can come to the Alpha from them, though are generally still doomed. Of course, it turns out that the creation of the doomed timelines and their involvement in the alpha timeline was also predestined, so either way, You Can't Fight Fate.
    • The one exception to this is John's retcon power, which allows him to make changes to the Alpha Timeline. These changes do not create doomed timelines, and unlike everything else in the Alpha timeline, did not already happen before they were made. Then it turns out even this isn't an exception. John's attempt to use this power to defeat Caliborn before he becomes Lord English is what turns Caliborn into Lord English. It's also the same event that turns Caliborn's juju into the juju that gives John his retcon power.
  • In Sluggy Freelance Bun-Bun's whole adventure in Timeless Space was based off this trope. As Uncle Time put it, "Life's so much funner with the paradox rules turned off."
  • How Time Travel works in Umlaut House, as Volair explained to his future son here:
    Volair: You can't change the future, Pierce. Past, future, it all fits together like a big, freaky jigsaw.
    Pierce (Who just accidentally broke the UST between his future parents): So the future you knows we're here?
    Volair: No, but I will if you tell me the date you're from.
  • Time travel in The Way of the Metagamer runs entirely on predestination. This doesn't stop it from being ludicrously convoluted.
  • In this xkcd, Black Hat Guy builds a one-use time machine and is sent back in time to kill Hitler. He succeeds... in a bunker in 1945.

    Web Originals 
  • Subverted on Le Visiteur du Futur season one, the Visitor claims that time travel does not work like that and that without the Time Brigad interference he could change the past but we are not given any evidence towards it and more and more towards him not knowing what he is doing as well as he pretends. Moreover, things like the Visitor's future self setting up a Stable Time Loop to help his past self escape custody points towards this trope. Eventually, during the climax of the season, the Founders spell out this trope and explain that their plan rely on it. So of course they are proven wrong when Raph manages to change the past. For the remaining of the serie the opposite trope is in full effect.
  • Red Panda Adventures:
    • "Eyes of the Idol" has an emissary from the Council of Mages tell the Flying Squirrel that the Nazis have attempted to travel back in time to the middle ages and conquer the past. However, a known issue with time travel is that Surprisingly Realistic Outcome occurs and most people who travel back or forward in time quickly die because they have no immunity to the sicknesses of the age and vice versa. This can be accounted for and avoided, but the Nazis never learned how. As a result, the Nazis who went back all died and, in the process, caused the Black Plague; their attempt to establish the Thousand-Year Reich a thousand years ago was always a part of the timeline.
    • In "The Honoured Dead", the Red Panda and Flying Squirrel are supposed to recover an artifact that disappeared ten years ago. They decide to go back in time and steal it, on the assumption that this was how it went missing in the first place. While there, they stop a man from committing a rather explosive suicide. Only after the fact does the Red Panda realize the man they saved is someone they know in the present day.
    • In "The Chimes at Midnight", a pair of would-be assassins come to 1945 Toronto from the future to murder the man who would become the Black Eagle on the day he becomes a superhero. They think that's because it's the day he gets his powers, but all they actually do is confirm that the Black Eagle becomes a name for the history books; much to the Red Panda's and Flying Squirrel's chagrin, since the Black Eagle is Harry Kelly, an agent of theirs they've known since he was a little boy who, thanks to this event, knows to lie about his origin story to ensure it happens.
  • Present in SCP-2000, the Foundation's equivalent of a "reset button," built to reverse the effects of end-of-the-world scenarios by rebuilding humanity from scratch. Not only has the reset been used an unknown number of times, attempts to change human history by resetting the world further back in the past than 20 years are implied to have caused both world wars.
    HMCL Note: No further proposals for behavioral or cultural modification will be accepted at this time. Previous attempts to ameliorate violent and sociopathic tendencies in humanity as a whole have already been implemented and deemed successful.

    Western Animation 
  • Played with in Beast Wars. After discovering that they're all on prehistoric Earth, Dinobot's mind becomes consumed with the question of whether he actually has free will, or whether this trope is in effect and all of his actions in the past are predetermined. His question is answered when he spies on Megatron and sees him experimenting with altering the future by blasting a mountain and checking an image of the future version of the mountain. When the image changes before their eyes to show the chunk missing, Dinobot realizes that the future can indeed be changed. Ironically, the knowledge that he is indeed free to make his own choices causes him to feel like he has no choice but to invoke the trope anyway, because Megatron wants to change the future for the worse and he's the only one close enough to stop him before it's too late, even if it costs him his own life.
    Dinobot: The question that once haunted my being has been answered: the future is not fixed, and my choices are my own. And yet... how ironic, for I now find that I have no choice at all! [transforms to robot mode] I am a warrior... Let the battle be joined....
    • Played with again in the finale. Dinobot II, being influenced by the original Dinobot's spirit sends the Maximals information concerning an Autobot shuttle docked in the Ark. Blackarachnia points out that the historical records never mentioned that the Autobots had a shuttle. Rhinox then exclaims that history is still being made, and uses the shuttle to save the day and take everyone home, which explains why the Autobots supposedly never had it.
  • In the Darkwing Duck episode "Paraducks", Gosalyn warns Darkwing not to interfere into the past when they went back in time to his childhood. At first he doesn't and returns to the present, only to find that S.H.U.S.H. doesn't exist, the King, a two bit thug from Darkwing's childhood has taken over St. Canard and he serves as the King's cowardly lackey, having never become Darkwing Duck. They go back and time and shut down the King for good and give little Drakey Mallard (Darkwing) the courage he needed.
  • The Fairly Oddparents special "The Secret Origin of Denzel Crocker": Timmy and 21st-century Cosmo were the ones responsible for making Crocker lose his fairy godparents and giving him the opportunity to partially get around the ensuing mass mindwipe thus causing his obsession with fairies, which also indirectly led to his own birth due to the disappointed scientists at Crocker's presentation in the '80s investing in Dinkleburg's parachute pants and causing him to break up with Timmy's mom, thereby getting his parents together.
    • Of course, in the original timeline, 1970s-era Cosmo would have exposed himself and Wanda as fairies due to his own stupidity. In addition, the original timeline Crocker did not have a functional scanner nor build one. Here, Crocker stole the one Timmy got from AJ before putting Cosmo's hair and having an effective fairy detecter, though not any more success.
    • This is also "confirmed" by being tied to a real-life history example, as Jorgen warns Timmy he is not allowed to interfere with March 1972 ever again after the episode's events, but suggests he is free to interfere with the rest of the year as much as he wants, as long as it does not hurt "President McGovern". In real life, Sen. George McGovern lost that year's presidential election in one of the most notorious landslides in election history, suggesting this is Timmy's doing as well.
    • Later episodes zigzag this example, by featuring a completely different version of Crocker's fairy godfamily, his childhood behavior, and how he loses them, as the show increasingly adopted negative continuity.
  • Played mostly straight in the Futurama episode "Roswell That Ends Well", where Fry and his crewmates end up in Roswell, New Mexico in 1947, where his grandfather Enos was stationed in the military, and he spends half the episode just trying to make sure his grandfather is not harmed. After the Professor warns him not to change the past unless he was already destined to change the past, Fry's extreme caution (and stupidity) result in his grandfather being vaporized by an atomic bomb. Although Fry previously recognized both of his grandparents from childhood, subsequent events and episodes nonetheless make it clear that the man Fry killed was not actually Fry's biological grandfather, and that his real grandfather is Fry himself.
    • Later episodes of the show reference this example as played straight, with "The Why of Fry" confirming that Fry was born with a genetic strength/defect (lacking a certain kind of brain wave) due to the events referenced, However, it may be mildly zigzagged as a previous episode seemed to imply Fry's father knew his father, and/or that Fry knew his grandparents, and he seems to recognise them in "Roswell That Ends Well". It could be partly explained by the infuriated Professor giving up all attempts at subtlety and launching a full-blown assault on Area 51 with the Planet Express ship to retrieve the parts necessary to get home...
      Professor: Choke on that, causality!
    • Also, Zoidberg is the Roswell alien, and Bender's body was the (alleged) remains of his spaceship.
    • The movie "Bender's Big Score" tinkers with this a lot, for example Bender was responsible for the destruction of New York seen in the first episode, the real-life election of George W. Bush as President, and for the previously unexplained fossilization of Fry's dog, Seymour, from "Jurassic Bark". This gets especially weird when Bender travels back in time and turns out to be responsible for giving the secret of time travel to himself.
  • The standard rule for time travel in Gargoyles.
    • Goliath tried to convince Demona in the past not to turn evil, and she seems to take it all to heart. Unfortunately, one guy, even the love of your life, telling you to "stay good" is trumped by centuries of being brutalized by humans. It's a true Tear Jerker to realize that Demona and Goliath were once really and truly Happily Married.
      • During the same incident, Demona also tried to warn her younger self of the destruction of her clan in order to turn her against the humans. Demona is in massive denial, however; she herself was one of the major causes of that very destruction, in one of her anti-human plots.
    • Xanatos uses this to his advantage. He gives two period coins to the Illuminati, along with a letter, giving instructions to delver them both to himself in the future. The coins are like pennies in the past, but by the present they're very valuable and are the coins that started his fortune. The letter, of course, is to tell him to do just that.
    • Later, Goliath attempts to use the time-traveling Phoenix Gate to save Griff from being killed during the Blitz in WWII London, after being accused of abandoning or murdering Griff by his companions. With incident after increasingly improbable incident occurring that indicates the universe has decided Griff is its new Chew Toy, Goliath ultimately concludes that fate will not allow Griff to get home and uses the Phoenix Gate to bring Griff back with him to the present, thus causing his original disappearance.
    • Mid-way through the Avalon arc, the Arch-Mage Took A Shitload Of Levels In Badass via a self-inflicted Stable Time Loop. It starts with his future self rescuing his past self from potential death and continues with instructions on how to use three mighty items of magic.
    • Goliath winds up in a Bad Future, and various characters suggest using the Phoenix Gate to fix it; Goliath repeatedly points out it doesn't work that way. In the end he is finally willing to try it, only to discover that this whole thing was All Just a Dream made by Puck as a ploy to get Goliath to hand the Gate over.
  • Used on an episode of Justice League Unlimited. Brainiac 5 imports heroes from the past because history mentioned an incident where heroes traveled to the future. He tries to avoid mentioning how it turned out, of course, just to be sure things go the way they're supposed to, with only two of the three returning. Nobody dies. Supergirl just decides to stay in the future.
  • ¡Mucha Lucha!: in Woulda Coulda Hasbeena, Señor Hasbeena uses a time portal to go back to 1972 and prevent a flash of light that briefly blinded him and killed his career as a professional luchador. Ricochet, Buena Girl, and Flea try to stop him because his time travel is altering the present and, in the ensuing fight, present-day Señor Hasbeena uses a signature move that creates the very flash of light that ruined him in the past.
  • In the season 2 episode "It's About Time" of My Little Pony: Friendship Is Magic, Twilight Sparkle is visited by her future self (from a week later, looking entirely worn) and told "whatever you do, don't..." with the sentence being cut off. Past Twilight then spends the whole week worrying about and trying to prevent whatever happens during the next week, with each incident causing her to gain the looks of Future Twilight, indicating she hasn't changed the future at all. She only then learns later that nothing actually happens. So she goes back into the past to tell her past self "Whatever you do, don't... worry about the future" only to end up being pulled back into the future right where it cut off for Past Twilight, setting the events into motion for the whole episode.
  • In The Powerpuff Girls Mojo Jojo goes to the past to kill the adolescent Professor Utonium before he can create the Girls. The Girls pursue him. It turns out that in the past Professor was a lazy ass and a bully with no interest in becoming a scientist and creating the Girls, if it weren't for Mojo's interference and the consequent encounter with and rescue by the Girls that gave him inspiration.
  • Invoked and averted in Teen Titans. Starfire ends up 20 years in the future, and the time-traveling criminal responsible for this explains this trope. Then she gets back to her time and finds that something has changed.
  • In the Time Warp Trio episode "The High and the Flighty", this trope ends up being The Reveal. After the trio's great-granddaughters listen to the final Distress Call of Amelia Earhart where she addresses a mysterious third party, the girls go on a rescue mission spearheaded by Freddi to find her supposed killer. After catching the Immoral Journalist attempting to stow away on her plane before takeoff, the girls return to the future only to find that the past went unchanged. A disheartened Freddi takes it upon herself to find out the truth and warps back to 1937 onto her plane, only for Amelia to catch her and repeat the lines in her distress call from the start shortly before the crash and Freddi warping back.


Video Example(s):

Alternative Title(s): Predestination Paradox, There Is Only One Possible Future, You Cannot Change The Future, Only One Possible Future


"Explains a lot."

After beating Cortex for the final time, his past self sees this a proof that his bandicoot general will work, and rushes to complete it. As this is happening, Crash knocks over a piece of equipment, which created Crash in the first place.

How well does it match the trope?

5 (15 votes)

Example of:

Main / YouAlreadyChangedThePast

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