->'''Riddick:''' Don't bother. Guards ain't there. They figured out the Necros are comin' for me. Plan was to clean the bank, ghost the mercs, break wide for the tunnel. And then somebody got a lucky shot off with this rocket launcher here... and took out the sled. Guards took off on foot, but rigged the door so no one could follow. They'll take the one ship in the hangar and leave everyone else to die.\\
'''Toombs:''' How come you know all this shit? You weren't even here.\\
'''Riddick:''' 'Cause it was my plan.
-->-- ''Film/TheChroniclesOfRiddick2004''

In a story where the villain is a WorthyOpponent, or if the hero and the villain are {{Mirror Character}}s, sometimes it's easy for the hero to predict their antagonist's every move. His {{Sidekick}} asks him how he knows what the BigBad is going to do next, and the hero responds by saying it's because he knows that if their positions were reversed, that's exactly what ''he'' would have done.

This is often used to show that the hero and the villain do in fact have more in common than the hero is usually willing to admit, or that they're on the same level intellectually. The line is most often uttered by [[AntiHero Anti Heroes]] or [[TheAtoner reformed villains]] who know the tricks of the trade and are able to think like a villain. In DarkerAndEdgier stories, this may push the hero into [[GreyAndGrayMorality morally gray territory]], letting the audience know that this character who they thought was a good guy may be no better than the villain himself. He doesn't blame the villain for [[KickTheDog kicking his dog]], running over his little sister, and [[EatsBabies devouring that orphanage full of babies]], because placed in his antagonist's situation, he would have done the same thing.

In speculative fiction stories, sometimes the hero knows what the villain will do because they may be [[EvilTwin effectively the same person]], in which case it is much easier for the hero to imagine himself in the villain's shoes.

Sometimes this line is uttered by the villain himself, who [[MyGodWhatHaveIDone understands the implications]] of his actions and realizes that the hero is only doing his job, and tells the hero that he doesn't hold it against him for [[AntiVillain trying to kill him]], and he should just get it over with, either because the villain knows that if he were the hero he would do the same, or because the villain wants the hero to know that he's just that much of a bastard and would be just as likely to kill the hero if he were given the chance. It's also a common line of TheAtoner, particularly if he or she is protecting someone from his or her former kind (such as {{Professional Killer}}s). Of course, kinder and gentler heroes will not take the villain up on his offer in order to show that there is, in fact, a difference between them and that the hero will not [[IfYouKillHimYouWillBeJustLikeHim stoop to the level of a villain]] by obliging his request.

Contrast ToKnowHimIMustBecomeHim. See IKnowYouKnowIKnow for the results of both sides following this line of thinking to its logical conclusion, factoring the other side's predictions into their own analysis.

----
!!Examples
[[foldercontrol]]

[[folder:Anime and Manga]]
* Shishio, the BigBad of the Kyoto Arc in ''Manga/RurouniKenshin'', wonders out loud if this is the reason Kenshin figured out his nefarious plot so quickly.
* L and Light of ''Manga/DeathNote''. All the time. Heck, L says as much in the first episode we actually see his face!
-->'''L''': After all, Kira is childish and hates to lose.\\
'''Soichiro''': And how do you know that?\\
'''L''': Because I am also childish and hate to lose.
* In the ''[[Anime/SonicTheHedgehogTheMovie Sonic The Hedgehog OVA]]'', Sonic's robot counterpart, the Hyper Metal Sonic was programmed through Sonic's life data, knowing his likes, dislikes, personality, and all of his thoughts. Being on the same wavelength, this leads to their even fight.
--> "You might know everything I'm going to do, but that doesn't matter since ''I'' know everything ''you're'' going to do! [[MemeticMutation STRAAANGE isn't it?!]]"
[[/folder]]

[[folder:Comic Books]]
* In the ''ComicBook/{{Batman}}'' series' event ''Comicbook/{{Knightfall}}'', the Batmobile is stolen. Batman gets it back, starts the car... and it explodes. Fortunately, he guesses this just in time to leap out of the car. ComicBook/{{Robin|1993}} asks him how he guessed the villain had wired the car to blow. Batman's response: "Because that's what I'd do."
* In ''Comicbook/TheLeagueOfExtraordinaryGentlemen'', this is how Moriarty knows that Holmes will try to fake his death after their encounter at Reichenbach Falls.
* ''ComicBook/{{Superman}}'' once formed a desperate alliance with Darkseid against Hank Henshaw. Darkseid realized Henshaw was going to go for the food stores to starve the populace with this logic.
[[/folder]]

[[folder:Fan Works]]
* In some {{Omake}} in ''Fanfic/HarryPotterAndTheMethodsOfRationality'', titled ''Lord of the Rationality'', [[Literature/TheLordOfTheRings Frodo]] thinks:
-->''A memory of awful clarity came over Frodo then, and a flash of black laughter, and the thought came to him that it was ''just'' what the Enemy would do. Only the thought came to him so: ''thus it would amuse me to do, if I meant to rule…
* In the ''Manga/MyHeroAcademia'' fic, ''{{Fanfic/Butterfly}}'', Izuku, after the revelation that [[spoiler: Butterfly is a version of himself from an alternate timeline]], is called upon to assist in strategies and plans against the villain.
* ''Fanfic/ShadowsOverMeridian'': Following the retreat of Elyon's army from Snowpoint, Jade discusses with the fortress' commanders about the possibility of the army trying to launch a new attack from the north. The terrain is so difficult to cross they find it unlikely, but Jade decides to keep an eye out in that direction in case a small group tried to sneak up on them. She states from her experience that if she were in the rebels' position, she'd choose the path the enemy would least expect them to use. [[spoiler:Vera's team is indeed trying to reach the Stone Nest from the north in an effort to find and assassinate Metalbeak, though [[RenegadeSplinterFaction this mission was not sanctioned by her superiors]].]]
[[/folder]]

[[folder:Film]]
* ''Film/Terminator2JudgmentDay''
-->'''John Connor:''' I gotta stop by my house. I wanna pick up some stuff.
-->'''T-800:''' Negative. The T-1000 would definitely try to reacquire you there.
-->'''John:''' You sure?
-->'''T-800:''' I would.
* Variation in ''[[Film/TheFastAndTheFurious Fast and Furious]]''. Brian tries to narrow down a list of suspects with the same name to figure out which one is involved with street racing. He has his FBI partner read off a list of the suspects' cars. After hearing about a Nissan 240SX with an illegal modification, he remarks that he's the one. His partner asks how he knows this and he replies "Because that's what I'd drive."
* In ''Film/TheChroniclesOfRiddick2004'', Riddick seems to know everything that happened in the fight that he wasn't there to witness, and then the others escaped in the chaos. When asked how he knew all that, he said it was his plan.
* In ''Film/SavingPrivateRyan'' TheSquad comes under attack by a sniper in a French village. The squad's sharpshooter Jackson spots a tall church tower and says, "That's where I'd be".
* In ''{{Film/Predators}}'', being a veteran hunter himself, Royce mentioned in detail how the predators would approach in killing their prey, quoted this exact line "that's what I would do".
** Mombasa takes it one step further, giving a detailed description of a sadistic trap for human prey, then saying, "I know because I have done this."
* In ''Film/PearlHarbor'', one of the naval intelligence analysts tries to convince Admiral Nimitz that the Japanese are going to attack Hawaii because it’s what he would do.
* In ''Film/TheLongestDay'', General Erich Marcks tells his adjutant he's going to win the upcoming wargaming exercise, where he's commanding the [=OpFor=], because he's going to break all the rules about amphibious attack across the Channel by not attacking the Pas de Calais during a stretch of good weather, but instead Normandy in bad weather. Like they're having right now. [[{{Irony}} He then dismisses the idea of actually doing it in real life because no one is that stupid and/or crazy.]] However, once he finds out the British are dropping decoy parachutists into Normandy, he realizes immediately that the Allies ''are'' that crazy and is the first German general officer to understand what's happening.
[[/folder]]

[[folder:Literature]]
* In Creator/NeilGaiman's short story ''Literature/AStudyInEmerald'', a crossover between Literature/SherlockHolmes and Creator/HPLovecraft, the detective tells the narrator that he figured out how the murderers got away based on the fact that he would have done the same thing. The twist is that [[spoiler: the narrator and the detective are Colonel Moran and Professor Moriarty, and the two murderers are Watson and Holmes]].
* Literature/FatherBrown, of the eponymous stories by Creator/GKChesterton, solves all of his mysteries this way. His gimmick is that, as a priest and confessor, he knows a great deal about how crimes are committed and what kind of people commit them.
-->"You see, I had murdered them all myself.... I had planned out each of the crimes very carefully. I had thought out exactly how a thing like that could be done, and in what style or state of mind a man could really do it. And when I was quite sure that I felt exactly like the murderer myself, of course I knew who he was."
* Literature/SherlockHolmes claims to be using the same method. In ''The Musgrave Ritual'', Holmes matches his wits against an unusually clever criminal (no, not [[ArchEnemy Moriarty]]). Afterwards, he tells Watson it was one of his easier cases; normally he has to adjust his deduction of what the criminal would do, since most people are significantly less smart than himself, Holmes. But in this case, what the criminal did is exactly what Holmes himself would have done, making it easier for Holmes to follow him!
* In ''Literature/HarryPotterAndTheDeathlyHallows'', [[RetiredBadass Alastor "Mad-Eye" Moody]] says that, even if [[BigBad Voldemort]] had believed their deception about taking Harry away on his birthday, rather than earlier to get him safely away while his protection still theoretically works, the guy would have to be crazy not to have an agent keeping watch, citing this trope as his basis.
* ''Literature/{{Pact}}'': in the final showdown with the demon Barbatorem, it compliments Blake's initial idea of trying to deny that it is the person it's possessing.
-->'''Barbatorem''': You had the right idea. Attack with words. Establish the facts, then use them. If the tables were turned and you were the enemy, me as the one who didn’t know any better, it’s what I’d do.
* The Literature/{{Quiller}} novel ''The Ninth Directive'' has Quiller tasked to plan the assassination of a "Very Important Royal Person" with the intent that this will show him exactly how the '''real''' assassin plans to do it. Turns out two can play at this game...
* Creator/TerryPratchett's ''Literature/GoingPostal'': [[BoxedCrook Moist von Lipwig]] explains to his love interest the way the BigBad's plan is going to work in. As she (ignorant of Lipwig's criminal past) remarks, 'You sound ''very'' certain', he replies, 'That's what I'd do, er... if I was that kind of person.'
* In a previous book in the same series, ''Literature/NightWatchDiscworld'', Sam Vimes watches an unsuccessful attack against a massive barricade that LaResistance have used to block off a large part of the city; it's a rather inefficient approach, he muses, and if he'd been in charge of leading the attack he'd have tried CuttingTheKnot by having men go into the cellars of buildings near to the barricade and break through walls until they could come out on the other side... although he'd had his people go through all the buildings near the barricade on ''their'' side and board up every cellar door they could find just in case.
--> '''Vimes:''' "... but then I wouldn't be fighting ''[[ProperlyParanoid me]]'', would I?"
* In Desmond Bagley's ''Windfall'', security company owner Max Stafford is on a BusmansHoliday to equatorial Africa. Visiting a suspicious agricultural foundation, he remarks to himself at a strategic location that there's probably a camera hidden up there... or there would be, if he were in charge.
* In ''Literature/WingsOfFire'', Qibli figures out that Darkstalker is using a spell to make himself a CharmPerson because that is what he would do if he had animus magic. It later turns out that [[spoiler:Darkstalker, being a mind reader, actually got the idea from ''Qibli'']].

[[/folder]]

[[folder:Live-Action TV]]
* In ''Series/{{Heroes}}'', Nathan cites his belief that the government would [[TheydCutYouUp capture and experiment on]] anybody with powers as exactly what he would do in the situation. [[spoiler:And then he did.]]
* In season one of ''{{Series/Lost}}'', Sawyer, after being stabbed by Sayid, tells Jack that he should just let him die, saying that he knows it's what Jack wants to do and that he would do the same to Jack if he were in his shoes. Of course, Jack [[ChronicHeroSyndrome saves him anyway]].
* Cameron uses this to predict the actions of enemy Terminators in ''Series/TerminatorTheSarahConnorChronicles''. Possibly a call back to the T2 example mentioned above.
* There's a scene in ''Series/BabylonFive'' where Sheridan predicts a particular move by the Shadows because "that's just what I'd do." Delenn is horrified by the notion of Sheridan thinking like the enemy.
* There's an episode of ''Series/CriminalMinds'' that pretty much epitomizes this trope, "Elephant's Memory". Spencer Reid has insight on the case because he identifies with the unsub, as they shared a history of being bullied in school. At one point he uses this exact phrase when asked how he [[spoiler: knew where the unsub would be]].
* As a white collar criminal hired to catch white collar criminals, Neal Caffrey of ''Series/WhiteCollar'' makes good use of this trope. He frequently deduces how criminals must have hidden their tracks by thinking over how he'd do it.
* ''Franchise/StarTrek'':
** In the ''Series/StarTrekTheOriginalSeries'' episode "[[Recap/StarTrekS1E14BalanceOfTerror Balance of Terror]]", this is Kirk's comment after [[WorthyOpponent the nameless Romulan commander]] dodges one of the Enterprise's attacks: "He did exactly what I would have done. I won't underestimate him again." The Romulan commander does pretty much the same thing, guessing Kirk's actions and motivations while saying "If I were their commander, that is what I would do."
** In the ''Series/StarTrekVoyager'' episode "[[Recap/StarTrekVoyagerS2E21Deadlock Deadlock]]", a NegativeSpaceWedgie duplicates ''Voyager'' and its crew, but only one can survive. This trope works better than usual because Captain Janeway really does know what her other self will do.
--->'''Janeway 1:''' You're going to [[SelfDestructMechanism self-destruct your ship]].\\
'''Janeway 2:''' What makes you say that?\\
'''Janeway 1:''' Because that's what I would do if your ''Voyager'' were intact and my ''Voyager'' were crippled.
** ''Series/StarTrekDeepSpaceNine'': Done from the perspective of a third party. To gain a powerful ally against the Dominion, Garak kills a Romulan senator and makes it look like the Dominion did it.
---> '''Garak''': The more the Dominion protests its innocence, the more the Romulans will believe they're guilty, because it's exactly what the Romulans would do in their place.
* ''Series/StargateSG1'': This is how the real SG-1 bests the evil, alternate universe team in "Ripple Effect." Of course, they had the added advantage of being basically the same people as their opponents.
* ''Series/DoctorWho''
** The TwoPartEpisode "[[Recap/DoctorWhoS32E5TheRebelFlesh The Rebel Flesh]]"/"[[Recap/DoctorWhoS32E6TheAlmostPeople The Almost People]]" has a lot of this, since all the one-off characters -- and the Doctor -- get duplicated throughout the course of the story. Most impressively, one of the doppelgangers manages to guess a password that her original created after the split happened, because it's the password that she would have used.
** In "[[Recap/DoctorWhoS39E6FluxChapterSixTheVanquishers The Vanquishers]]", the Doctor is split into [[MesACrowd three Doctors]] in the same timeline but different areas of Space. One Doctor turns up to rescue the other and traps the BigBad in his own torture device. When the rescued Doctor says, "That's what I would have done!" her (somewhat confused) companion points out, "That's what you ''did'' do!"
* This is how the titular Series/{{Castle|2009}} helps solve crimes: by being GenreSavvy and knowing what he would write in a given situation.
* ''Series/{{Dexter}}'' has an exchange in the same spirit as the trope when it comes to eliminating a suspect:
--> '''Dexter:''' The guy we're looking for wouldn't turn dead dirty things into living cartoons, he'd find that pathetic.
--> '''Debra:''' How do you know?
--> '''Dexter:''' [{{Beat}}] Because it is pathetic.
* ''Series/PersonOfInterest'': Ex-CIA assassin John Reese does this a lot (likely to troll his TechnicalPacifist partner Harold Finch) in response to the VillainOfTheWeek's murder plot.
* ''Series/TheProfessionals'': In "Not A Very Civil Servant", a CorruptCorporateExecutive arranges for TheDragon to kill off an accountant who knows too much. Later the executive goes through the accountant's files and [[OhCrap finds evidence that he had been making photocopies of every document]] as BetrayalInsurance. When TheDragon asks how he knew to look in the first place, the executive reveals that he's been taking exactly the same precautions against his [[TheStarScream smarter Dragon betraying him]].
* ''Series/ThePunisher2017'': In a flashback to his service in Kandahar, Frank Castle cites this trope when he tries to warn his superiors the next objective is a Taliban trap. [[CassandraTruth They don't listen.]]
[[/folder]]

[[folder:Tabletop Games]]
* The Shadow Lords in ''TabletopGame/WerewolfTheApocalypse'', a tribe with a reputation for ambition and conniving, have this as their flavor quote in the core rulebook.
* That is the default mode of playing ''TabletopGame/{{Chess}}''. Also, most computer chess algorithms involve [[PerspectiveFlip flipping the perspective]] in order to guess the opponent's moves.
[[/folder]]

[[folder:Video Games]]
* At the end of the ''Lara's Shadow'' DownloadableContent for ''VideoGame/TombRaiderUnderworld'', [[https://www.youtube.com/watch?v=tbC2AhEcfu4&NR=1 Lara confronts her doppelganger]] after gaining control of it.
-->'''Lara Croft:''' "What the hell are you?"\\
'''Doppelganger:''' "[[foldercontrol]]

[[folder: I am you, with the flaws removed. ]]
"\\
'''Lara:''' "If you were your own master, what would you do?"\\
'''Doppelganger:''' "[[/folder]]

[[folder: What would ''you'' do? ]]
"
** [[spoiler:Based on that Lara gives the doppelganger its freedom. It goes on to overthrow Natla, its former master, and drown her in a pool of poisonous eitr.]]
[[/folder]]

[[folder:Web Animation]]
* In ''WebAnimation/RedVsBlue'' season 15, the heroes need to figure out how [[spoiler:the Blues and Reds]] are planning to destroy the UNSC, and turn to Sarge since he's as dumb and crazy as they are. When asked what he do if he wanted to get to a heavily fortified base, he would tunnel underground. And from there along with knowing their enemy is heading to the other side of the globe from the UNSC, the heroes realize that [[spoiler:Temple]] is planning to do exactly that.
[[/folder]]

[[folder:Webcomics]]
* ''Webcomic/DarthsAndDroids'' has this exchange early in the ''Solo'' chapter:
-->'''Rio:''' How do you figure anyone would be stupid enough to come to a war zone to steal equipment?\\
'''Chi’ra''' ''(Jim's character)''''':''' It’s what I would have done!
[[/folder]]

[[folder:Web Original]]
* ''WebVideo/DragonBallZAbridged,'' when King Kai is relating Goku's fight with Freeza to Yamcha, Tien, and Chiaotzu, the latter correctly guesses that a desperate Freeza "Blew himself up, along with his opponent" because that's exactly what he tried against Nappa. King Kai's response is "Yeah, but this time it ''worked.''
[[/folder]]

[[folder:Western Animation]]
* In ''WesternAnimation/SouthPark'' Season 18 episode 2, "Informative Murder Porn," the boys track down the kid who was teaching their parents Minecraft. The kid comes up with an excuse and the boys leave him alone, only for Cartman to realize the excuse would exactly be the sort of thing he'd say if he was caught.
[[/folder]]

[[folder:Real Life]]
* Generals often predict each other's plans in this manner when the required intelligence isn't available. This approach can backfire horribly if the predicting general failed to understand that his opponent is more ruthless than he is, or when the enemy has access to information that the predicting general doesn't know exists.
** Some generals also take this one step further. [[IKnowYouKnowIKnow They knew their enemy will try to predict their actions in this manner]], and therefore alter their plan accordingly.
*** This can lead to some pretty interesting battles. For instance, during WWII, the Germans thought the invasion of Normandy was a diversionary attack while the assault on Pas-de-Calais (which is geographically closer to the British Isles and also was a natural harbor with a well-established port, and therefore the more reasonable target) was the real push; in reality, the situation was reversed. The Allies were perfectly aware that the Germans had predicted they would strike Pas-de-Calais, so they encouraged that line of thought with a massive misdirection campaign and struck elsewhere.
*** As an example of how circular this can get, the Germans distrusted intelligence indicating that Normandy was the real invasion for some time because the Allies had [[http://en.wikipedia.org/wiki/Operation_Mincemeat gone to extreme lengths]] to plant deceptive intelligence prior to the invasion of Sicily the year before.
*** In UsefulNotes/TheAmericanCivilWar, the officers on both sides generally all attended West Point, had the same instructors, studied the same books, et cetera. Some of them had even fought together in the UsefulNotes/MexicanAmericanWar. The two combined tropes led to the Civil War being the U.S.’ bloodiest war.
*** It could also be said that this was the case for Napoleon's greatest victory, Austerlitz. There he out-thought his opponent by predicting that they would attack the weak point on the French right wing. Napoleon used it as a trap to lure the Austro-Russian army off of the high ground so his troops could attack and capture it, cutting his enemies' army in half in the process.
** A common mistake that gets made as a result of this is known as "mirror-imaging". The assumption that the enemy will use the same tactics you would if the situations were reversed can be deeply flawed if the enemy's cultural background and tactical doctrines are sufficiently different from your own. This is why the United States and Soviet Union were often completely wrong in assessing each other's intentions during the UsefulNotes/ColdWar.
* Frank Abagnale of ''Film/CatchMeIfYouCan'', his autobiographical book and movie. Eventually, he ends up working with the government tracking down con men like himself. The few scenes you see of him doing this in the movie include him making similar remarks to the trope name.
[[/folder]]
----