History Main / YouAlreadyChangedThePast

* Happens at the very end of ''Literature/TheSecretsOfTheImmortalNicholasFlamel'' books.

* ''The Skull'' by Creator/PhilipKDick. 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 RousingSpeech supposedly given by the Founder never actually happened, but was a result of history being embellished after his death. [[https://www.gutenberg.org/files/30255/30255-h/30255-h.htm All he said]] was:

* Diana Gabaldon's ''Literature/{{Outlander}}'' series runs into this a lot.

* ''There Will Be Time'' by Creator/PoulAnderson. A substantial number of humans have had the innate ability to TimeTravel 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 [[AfterTheEnd postapocalyptic]] revival of civilization--at ''least'') that the inability to change the past comes up only rarely--but the protagonist is nearly broken [[spoiler:when his Byzantine wife dies of an illness because other travellers have abducted him to the future]].

* Present in [[Wiki/SCPFoundation 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.

* ''Film/AliceThroughTheLookingGlass'' 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 [[spoiler: 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.]]

* ''Film/DejaVu2006'': The first few attempts at actually changing the past just end up causing things the characters and audience have already seen happen. [[spoiler: Eventually, for the sake of having a happy ending, they do manage to make a change that works.]] This could be a case of [[spoiler:[[SubvertedTrope 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 Website/TheOtherWiki has a [[http://en.wikipedia.org/wiki/File:Deja_Vu_Timeline.png 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.]]

* ''There Will Be Time'' by Creator/PoulAnderson. A substantial number of humans have had the innate ability to TimeTravel 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 [[AfterTheEnd postapocalyptic]] revival of civilization--at ''least'') that the inability to change the past comes up only rarely--but the protagonist is nearly broken [[spoiler: when his Byzantine wife dies of an illness because other travellers have abducted him to the future]].

* Eoin Colfer's ''Literature/ArtemisFowl'' Time Paradox [[spoiler: The matter is discussed before they actually TimeTravel 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.]]

** His short ''Literature/AllYouZombies'' involves a time agent making sure he completes the correct steps to finish the changes he remembers happening earlier in his life.[[spoiler: 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.]]

* ''Literature/TheDandelionGirl'', a short story by Robert F. Young; the trope specifically applies to Julie. [[spoiler: In the end, it is revealed that Anne and Julie are actually [[TwoPersonLoveTriangle 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]].

* The climax of ''Literature/HarryPotterAndThePrisonerOfAzkaban''. 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 NeverShallTheSelvesMeet. [[spoiler: Harry breaks the NeverShallTheSelvesMeet 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 [[StrongFamilyResemblance 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 ([[TrickedOutTime the executioner actually realized he was missing and swung at a fencepost in frustration]]), and use him to get Sirius to safety after he's imprisoned in the castle.]]

* Happens quite a lot in ''Literature/CountAndCountess'', 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. [[spoiler: Which gives Hunyadi plenty of time to rouse the Black Forces against Vlad and stop him in his tracks.]]

** [[DoubleSubversion Double (Triple?) Subversion]]: On Esilio, a planet with MerlinSickness, 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 MerlinSickness, 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. [[spoiler: 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.]]
** [[InvokedTrope Invoked]]: The ''Surveyor'' returns to the ''[[GenerationShip Peerless]]'' after a long absence to find that the inverted TimeCapsule messaging system (which essentially lets people send email back in time) has been built, but also [[spoiler: 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 [[YouCantFightFate Can't Fight Fate]] since the universe is an absolutely StableTimeLoop, 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.]] [[MindScrew Yeah]].

* ''Literature/TheLicaniusTrilogy'': Since this work deals heavily in themes of fate, predestination, and free will, this trope comes up a lot. [[spoiler: 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.]]

** [[spoiler: Valen/Sinclair doesn't need to be ''re''incarnated. 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.]]

** There ''are'' some odd things involving [[spoiler:''Babylon 4'']], namely Sinclair getting visions of a BadFuture, 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 ([[spoiler:his friends don't actually die, and the station ''is'' destroyed in the future, but it's actually decommissioned and scuttled]]). [[WordOfGod Word of God]] is that the visions are [[spoiler: what would have happened if he had not traveled back in time]].

** The [[spoiler: TARDIS explosion]] in [[Recap/DoctorWhoS31E12ThePandoricaOpens "The Pandorica Opens"]]/[[Recap/DoctorWhoS31E13TheBigBang "The Big Bang"]] was successfully prevented (in a fairly static timeline, [[MindScrew 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 [[TimeyWimeyBall temporal weirdness]] which comes with this is the fact that she was around to see a crack in [[Recap/DoctorWhoS31E5FleshAndStone "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 StableTimeLoop".

** Particularly annoying with Sayid [[spoiler: 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 [[spoiler: 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]]. [[NiceJobBreakingItHero Nice going, guys!]]

** Sam [[spoiler: successfully]] tries to save his brother's life in Vietnam, which alters history and results in [[spoiler: 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. [[spoiler: 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 ExecutiveMeddling, 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.

* Heartbreakingly (how else?) done in ''Series/{{Supernatural}}'' when Dean is sent back in time to 1973 and meets his father. He [[SetRightWhatOnceWentWrong 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 [[spoiler: who is manipulated into making a [[DealWithTheDevil deal with the YED]], thus dooming his family]].

* 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. [[spoiler: 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.]]

* The ''VideoGame/LegacyOfKain'' 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 GambitRoulette ever. One of the protagonists [[spoiler: ''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 day...[[spoiler: it lands on its edge.]]"

* ''VideoGame/FinalFantasyVIII'' ending has this trope, with [[spoiler: 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.]]

* In ''VideoGame/PrinceOfPersiaWarriorWithin'', 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, [[spoiler: 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 ScrewDestiny and subvert this.

* ''VideoGame/{{Braid}}'' features this [[spoiler: when you try to rescue the princess - and then see that she was running away from you instead...]]

* ''VisualNovel/SteinsGate'': Understanding this concept is what allows [[spoiler: Okabe (with some help from his [[TimeTravelTenseTrouble "future"]] self) to turn the constant stream of {{Downer Ending}}s into something much more pleasant.]] His early episodes [[AwesomeEgo 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 ForWantOfANail and RubberBandHistory most of the time. Sending messages to the past can have fairly far-reaching implications (such as [[spoiler:[[GenderBender changing the actual biological sex]] of a [[DudeLooksLikeALady person]]]]), and the butterfly effect is explicitly called out by name. However, some events have greater inevitability than others (such as [[spoiler:Mayuri's death in the beta world line by a series of increasingly {{Contrived Coincidence}}s]]).
* In ''VisualNovel/NineHoursNinePersonsNineDoors'': [[spoiler: Akane]] sets up such a time loop to ensure her survival. [[spoiler: 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.

* A three-part episode of ''WebAnimation/RedVsBlue'' 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 [[spoiler: including his own 'demise']].

** The others experience much the same thing when ''they'' get to time-travel later on. [[spoiler: 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.

* Played mostly straight in the ''WesternAnimation/{{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 [[ItMakesSenseInContext 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 [[TrickedOutTime man Fry killed was not actually]] Fry's biological grandfather, and that his real grandfather is [[spoiler: Fry himself]].

** Xanatos uses this to his advantage. He gives two period coins to the Illuminati, along [[WriteBackToTheFuture with a letter]]. 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.

* In ''VideoGame/CrashBandicoot4ItsAboutTime'', the final dimension is set on Cortex's island just before the events of the original VideoGame/CrashBandicoot, 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.

* Featured in one of the videos leading into ''Ride/TheSimpsonsRide'' at Ride/UniversalStudios. 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.

* A three-part episode of ''Machinima/RedVsBlue'' 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 [[spoiler: including his own 'demise']].

*** Probably because the first situation occured in the Stable Time Flow while another was facilitated by Unstable Time Flow (and that reality itself was unraveling around everyone).

* ''Film/DejaVu2006'': The first few attempts at actually changing the past just end up causing things the characters and audience have already seen happen. [[spoiler: Eventually, for the sake of having a happy ending, they do manage to make a change that works.]] This could be a case of [[spoiler:[[SubvertedTrope 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 Wiki/TheOtherWiki has a [[http://en.wikipedia.org/wiki/File:Deja_Vu_Timeline.png 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.]]

* A DoubleSubversion occurs at the very end of ''VideoGame/{{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 NiceHat… the very same hat he had entered the room wearing at the beginning of the game.

** Played with in ''Film/BackToTheFuture'', 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 actually 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 Music/ChuckBerry 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 is still mayor in the original timeline, meaning he would have found inspiration elsewhere.

* ''{{Series/Legion|2017}}'': 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 PsychicPowers. 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.

** Remake ''Film/TwelveMonkeys'' has the same scene with a twist: he is shot by airport security [[YouCannotChangeTheFuture trying to prevent the apocalypse that made him time travel in the first place]].
* An interesting case is the movie ''Film/{{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 [[TrickedOutTime 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 [[YouCannotChangeTheFuture future-seeing machine]]).

* Somewhat subverted in the ''WesternAnimation/InvaderZim'' episode "Bad, Bad Rubber Piggy" had Zim send a rubber piggy into Dib's past at crucial points to kill him, only he survives by an inch each time (though every time he comes close to death, he's given robotic body parts from his father due to losing his own) and after his tampering with the past results in an angry Dib in a HumongousMecha bent on killing him, he sends his last piggy to the past to warn him not to send any piggies to the past in the first place. This returns the timeline to its original state, but because the piggies replace objects in the past, the plan only worked because the piggy replaced Zim's ''brain'' (he got better).

** Subverted in the second season episode, "Back There", where 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" where 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.

* Subverted in the second season ''Series/TheTwilightZone1959'' episode, "Back There", where 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.

* In ''Series/TheTwilightZone1985'' episode "[[Recap/TheTwilightZone1985S1E20AProfileInSilver Profile in Silver]]", a time travelling historian saves his ancestor UsefulNotes/JohnFKennedy from being assassinated. The resulting damage to space time then creates a timeline where WorldWarIII 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 ''Series/TheTwilightZone'' (2000s revival) 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.

* ''Manga/RedRiver1995'' has [[OrdinaryHighschoolStudent Yuri]] 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.

* ''Manga/TsubasaReservoirChronicle''. 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 [[spoiler:pulls a FaceHeelTurn halfway through is fated to pull a HeelFaceTurn 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 [[MagicAIsMagicA lost track of their time-travelling system]] as the MindScrew got more and more complicated...
* In ''Manga/RaveMaster'', 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 [[spoiler: 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.]]

%% * ''Film/TwelveMonkeys'', as well as its inspiration, ''Film/LaJetee''.
* The first ''[[Film/TheTerminator Terminator]]'' film 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 [[StableTimeLoop 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.
* Harve Bennett's explanation for why the ''Enterprise'' crew was so careless about altering history in ''Film/StarTrekIVTheVoyageHome'' seems to be (he says it in a rather disjointed way) that this trope is in place. Although this [[TimeyWimeyBall 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.
* This gets covered regarding the movie ''Film/HappyAccidents'' very well [[http://www.mjyoung.net/time/happy.html here]].
* This is a central theme of brilliant Spanish Mystery thriller ''Film/TimeCrimes''.
* In ''Film/DejaVu2006'', the first few attempts at actually changing the past just end up causing things the characters and audience have already seen happen. [[spoiler: Eventually, for the sake of having a happy ending, they do manage to make a change that works.]] This could be a case of [[spoiler:[[SubvertedTrope 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 Wiki/TheOtherWiki has a [[http://en.wikipedia.org/wiki/File:Deja_Vu_Timeline.png 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.
* An interesting case is the movie ''Film/{{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 [[TrickedOutTime 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 [[YouCannotChangeTheFuture future-seeing machine]]).
* In the 2007 film ''Film/{{Premonition}}'', Creator/SandraBullock lives the week of her husband's death out of order. [[spoiler:She's unsuccessful in her attempts to save him, as on the last day she accidentally causes his death by preventing another one.]]

* In ''Film/TheFinalCountdown'', 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 [[spoiler: Sheen finds out that the mysterious billionaire is that officer, made wealthy by 30 years of fore-knowledge]].
* In ''Film/GodzillaVsKingGhidorah'', 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.
* ''Film/AliceThroughTheLookingGlass'' 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 [[spoiler: 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.]]
* In ''Film/{{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, [[spoiler: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]].

* In ''Film/DejaVu'', the first few attempts at actually changing the past just end up causing things the characters and audience have already seen happen. [[spoiler: Eventually, for the sake of having a happy ending, they do manage to make a change that works.]] This could be a case of [[spoiler:[[SubvertedTrope 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 Wiki/TheOtherWiki has a [[http://en.wikipedia.org/wiki/File:Deja_Vu_Timeline.png 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.]]

* The climax of ''Literature/HarryPotterAndThePrisonerOfAzkaban''. 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 NeverShallTheSelvesMeet. [[spoiler: They wind up causing some of the things their past selves experience, like breaking a jar. Harry also breaks the NeverShallTheSelvesMeet 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 [[StrongFamilyResemblance 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 ([[TrickedOutTime the executioner actually realized he was missing and swung at a pumpkin in frustration]]), and use him to get Sirius to safety after he's imprisoned in the castle.]]

* Subverted in the crossover ComicBook/{{Spawn}} / ComicBook/{{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 EvilGloating... 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.

* ''TabletopGame/WarhammerFantasyRoleplay'': The Celestial Order of wizards, who specialize in {{astrolog|er}}y and reading the future, have a simple method for selecting new leaders -- they appoint the person they foresee being appointed. This paradox, as well as the question of what force actually determines who gets appointed, keep the current leader awake at night.