History Main / RetroactivePreparation

* {{Homestuck}}: {{Stable Time Loop}}s are everywhere in this series, and there are devices that can send anything to any point in time as well as devices that can pull anything from any point in time as long as no paradoxes are created. The best example is the Bunny - [[ZigZaggedTrope although it also helps cause the problems it was created to solve]].

* [[spoiler:Old!]]Loki in ''Comicbook/LokiAgentOfAsgard'' went back in time (or maybe in [[TheoryOfNarrativeCausality story]]) to create the sword that was used to free [[spoiler:Thor from his parasitic influence]], because he wanted to wreak havoc without the restrictions of, well, basically [[spoiler:DemonicPossession]].

* The Catholic Church eventually adopted the doctrine that this [[TimeTravelTenseTrouble happens/has happened/will happen]] when they pray for the souls of the dead. The official line is that {{God}} hears their request in the present and, since it's eternal[[note]]'Eternal' in this case is a specific theological term meaning 'existing and acting in all points of time as if they were the present', rather than the common usage meaning 'endless'[[/note]], actively [[TimeTravelTenseTrouble manipulates]] the person prayed with a little bit so they'll be just that bit closer to repenting and thus them not spending as long in purgatory before going to heaven/not ending up in hell and staying there forever.

* This is what Catholics believe [[TimeTravelTenseTrouble has happened]] when they pray for the souls of the dead. {{God}} hears their request in the present, but since He is eternal[[note]]'Eternal' in this case is a specific theological term meaning 'existing and acting in all points of time as if they were the present', rather than the common usage meaning 'endless'[[/note]], He works in the past to convince the person who [[TimeTravelTenseTrouble will be]] prayed for to repent.

Let's say your favorite show is about to air, but you forgot to program your [[TechnologyMarchesOn VCR or DVR]] to record it. You run up to your front door, discover it locked, and realize you don't have your keys. What do you do? Break a window? Bust down the door? Drop down the chimney? Watch it at a neighbor's house? Hurry! There's less than a minute left! Oh, if only you'd thought to leave a key hidden under the doormat or something!

* The Francise/KingdomHearts series is the result of the BigBad Xehanort doing this to himself. He uses his past self in his schemes to get the X-Blade, thus planting a seed of darkness in his past self's heart, which acts as a catalyst to eventually corrupt him into the monster that he becomes, [[StableTimeLoop who eventually uses his past self in his schemes...]]

* ''Manga/{{Bleach}}'': Fullbringers manipulate souls, and according to them all matter has souls. [[spoiler:Tsukushima's special power allows him to become a [[SelfInsertFic self-insert character]] in anyone's lives by stabbing them, retroactively becoming their friend, lover, commander, etc. Then he reveals that he can do this to ''any inorganic matter'' by retroactively preparing a trap for his opponent, Byakuya. Oh, and BTW? He's seen all his moves too.]]

** Because of this rule, The Doctor was able to save River Song in ''Forest of the Dead''.
** This is also the Doctor's only recourse in ''Blink'', not so much helping himself as helping Sally Sparrow defeat the Weeping Angels in 2007 because they sent him back to the 1960s without the TARDIS.
** Parodied in ''The Curse of the Fatal Death'', where both sides attempt this. Repeatedly.
** Used in Season Finale "The Big Bang", repeatedly, where we first see the Doctor show up and give random orders, leave, come back a second later, give more, and repeat a few times. Later, we see it from the other side, and learn he's doing this in real time in the future as he figures out what he needed to have already have happened. Thanks to the Timey-Wimey Ball in that universe, he probably can't rely on things he's going to do later, so going back and retroactively doing them the instant before he needs them is safer.
** Used rather cleverly at the very end, when we find out that two events earlier in the series that didn't make much sense at the time (the TARDIS returning to young Amy waiting on the Doctor, despite us knowing that she didn't see him again till twelve years later; and the Doctor telling Amy to 'remember what I told you when you were seven') turn out to be future versions of the Doctor, setting things up so Amy will remember him. [[spoiler:Well, actually, it's the Doctor reversing through his own timeline as he gets erased from time, so he's really just taking advantage of involuntary time travel rather than having planned it, but it works the same way.]]

* ''KamenRiderDouble'' has an odd variation on this. The Yesterday Dopant has the power to make someone do whatever they were doing [[ExactlyWhatItSaysOnTheTin exactly 24 hours ago]]. When Double shows up to fight it, Yesterday specifically baits him into actions that, when affected by Yesterday's power the next day, will cause him to try and assassinate a public figure.

A TimeTravel trope, RetroactivePreparation is a twist on the YouAlreadyChangedThePast plot where the existence of a StableTimeLoop works to the advantage of the character's goals rather than thwarting them.

* Pretty much the ENTIRE Francise/KingdomHearts series is the result of the BigBad Xehanort doing this to himself. He uses his past self in his schemes to get the X-Blade, thus planting a seed of darkness in his past self's heart, which acts as a catalyst to eventually corrupt him into the CompleteMonster that he becomes, [[StableTimeLoop who eventually uses his past self in his schemes...]]

* ''{{Stargate SG-1}}'' two-part episode "Moebius" may not be a straight example, but it probably felt like that to the characters. In the beginning, they need a Zero-Point Module, decide to go back in time to when there was one on Earth, then hide it in a recently-discovered excavation site. At the end, General O'Neill finds himself watching a video of himself and his team explaining how and why they went back in time, which was recently discovered at an excavation site alongside the Zero-Point Module they needed. The only part O'Neill understands is that he doesn't have to do anything now that someone from another timeline did it for him.

** The movie ''[[StargateContinuum Continuum]]'' brings up the question: what if both sides have time travel technology? Ba'al attempts to use this rule, but is defeated when Mitchell travels back even further and stops him in the past. Confused yet?
** The ''StargateAtlantis'' crew probably wouldn't have survived the first episode if it weren't for the efforts of an alternate Dr. Weir and this trope.

* In ''The Disappearance of LightNovel/HaruhiSuzumiya'', Kyon makes use of this to [[spoiler: mobilize the SOS-dan to come back in time and save himself from Asakura and fix the whole parallel universe thing.]]

* A variation occurs in ''SupermanAndBatmanGenerations III'': [[spoiler:{{Darkseid}}'s plan to conquer Earth starts by sending an invasion fleet to attack the planet. Should they fail, the survivors time travel back 100 years and try again, and so on and so forth.]]

* ''{{Harry Potter and the Methods of Rationality}}'' plays {{Xanatos Speed Chess}} with this trope.

* In ''{{Paycheck}}'', Ben Affleck's character does this not by going back in time, but by seeing the future before being stricken with amnesia.
* The ''Film/BackToTheFuture'' films are an example of a universe where this does not work. E.g., in the third film, the only thing they need is a gallon of gas. Marty (from the end of the film) does ''not'' go back in time to give a jerrycan to Marty (stuck in 1885).
** Which makes perfect sense, because he can't. The [=DeLorean=] is destroyed immediately upon returning.
*** Ah, but if he'd received a jerrycan of gas, the [=DeLorean=] wouldn't have been on the train tracks when it returned to the future (since the train wouldn't have been necessary), thus wouldn't have gotten smushed, and thus would have been available to take the gasoline back.
** Similarly, the first movie's problem is not solved by personal-future-Marty showing up with more plutonium, but this could have been a result of Marty deciding that his 1985 is better off thanks to his improvising in 1955.
** The third movie is a sort-of case. The 1985 Doc Brown is zapped from 1955 to 1885, leaving Marty in 1955 without a time machine. And Doc can't fix the machine to go back and get him, so he simply leaves it buried in a mine, and has a letter sent for that particular time and place, informing Marty of the situation and including directions for 1955 Doc to fix it. So from Marty's point of view, as soon as Doc vanishes a time machine and instructions for repairing it were suddenly there all along.
** Ultimately the Back to the Future universe counts as an aversion of this trope because any interaction with your past or future selves ''can'' create a time paradox that can destroy the universe. Granted, that's a worst-case scenario. The destruction might be limited to our own galaxy.

* In the ''KimPossible'' movie "A Sitch in Time", [[spoiler:Shego]] used the time monkey idol to change a whole lot of things, including making tons of money by buying a big company before the bubble burst, [[TimeyWimeyBall causing Ron to move to Norway]], [[TakeOverTheWorld Taking Over The World]] by mind probing the entire population, [[TimeyWimeyBall travel back to the future!past to tell her past self to steal the Time Monkey Idol]].

* {{Harry Potter and the Methods of Rationality}} plays {{Xanatos Speed Chess}} with this trope.

* In ''Anime/PuellaMagiMadokaMagica'', Akemi Homura tried hard to save Kaname Madoka this way. [[DeterminedDefeatist Repeatedly]].

Compare TrickedOutTime, the circumvention of the StableTimeLoop, and contrast YouAlreadyChangedThePast, the failed attempt to SetRightWhatOnceWentWrong. See also TemporalParadox. For when video game players (ab)use save states to do this in their games, see SaveScumming.

Compare TrickedOutTime, the circumvention of the StableTimeLoop, and contrast YouAlreadyChangedThePast, the failed attempt to SetRightWhatOnceWentWrong. See also TemporalParadox.

** Actually the Back to the Future universe counts as an aversion of this trope because any interaction with your past or future selves ''can'' create a time paradox that can destroy the universe. Granted, that's a worst-case scenario. The destruction might be limited to our own galaxy.

* This is the premise of PhilipKDick's short story "Paycheck".

* A card in ''TabletopGame/{{Chrononauts}}'' is called "Memo from Your Future Self". it effectively works like this, instantly negating the last card another player played. The German Chocolate Cake artifact can also be used as a Memo and the image on the card shows it having a postcard attached. (WordofGod says that it is not the postcard but the cake itself, and that the cake is just so good that it distracts the other player from [[TimeTravelTenseTrouble doing what they just did]]. Presumably the postcard is just to tell yourself when to use it.)

* A card in ''TabletopGame/{{Chrononauts}}'' is called "Memo from Your Future Self". it effectively works like this, instantly negating the last card another player played. The German Chocolate Cake artifact can also be used as a Memo and the image on the card shows it having a postcard attached. Though, WordofGod says that it is not the postcard but the cake itself, and that the cake is just so good that it distracts the other player from [[TimeTravelTenseTrouble doing what they just did]]

* A card in ''TabletopGame/{{Chrononauts}}'' is called "Memo from Future Self". it effectively works like this, instantly negating the last card another player played. The German Chocolate Cake artifact can also be used as a Memo and the image on the card shows it having a postcard attached. Though, WordofGod says that it is not the postcard but the cake itself, and that the cake is just so good that it distracts the other player from [[TimeTravelTenseTrouble doing what they just did]]