->'''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/TheChroniclesOfRiddick''

In a story where the villain is a WorthyOpponent, or if the hero and the villain are NotSoDifferent, 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 [[GrayAndGreyMorality 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 [[CloningBlues 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 ProfessionalKillers). 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.


[[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!
* 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: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. Robin 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 a supervillain. Darkseid realized the villain was going to go for the food stores to starve the populace with this logic.

[[folder:Fan Works]]
* In some {{Omake}} in ''Fanfic/HarryPotterAndTheMethodsOfRationality'', titled ''Lord of the Rationality'', [[LordOfTheRings 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...

* ''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/TheChroniclesOfRiddick'', 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 itís 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.

* In Creator/NeilGaiman's short story ''Literature/AStudyInEmerald'', a crossover between 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 commits 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.
* 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.
* Creator/TerryPratchett's ''Discworld/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 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.

[[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.
* In the ''[[Series/StarTrekTheOriginalSeries Star Trek]]'' episode "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 [[NotSoDifferent 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."
* ''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.
* The ''Series/DoctorWho'' two-parter "The Rebel Flesh"/"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 she would have used.
* This is how the titular Series/{{Castle}} helps [[TheyFightCrime 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.

[[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:Video Games]]
* At the end of the ''Lara's Shadow'' DownloadableContent for ''VideoGame/TombRaiderUnderworld'', [[http://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:''' "[[AC:I am you, with the flaws removed.]]"\\
'''Lara:''' "If you were your own master, what would you do?"\\
'''Doppelganger:''' "[[AC: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:Web Original]]
* In ''WebVideo/DragonBallZAbridged,'' when King Kai is relating Goku's fight with Freeza to Yamcha, Tien, and Chautzu, 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: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, for Cartman to realize the excuse would exactly be the sort of thing he'd say if he was caught.

[[folder:Real Life]]
* Generals often predict the each other's plans when the required intelligence isn't available in this manner. This approach can backfire horribly if the predicting general failed to understand his opponent is more ruthless then he is, or when the enemy has access to information 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 therefore the more reasonable target) was the real push; in reality, the situation was reversed. The Allies were perfectly aware 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 that indicated 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.
* Frank Abagnale of ''Film/CatchMeIfYouCan'', his autobiographical book and movie. Eventually, he ends up working with the government tracking down conmen like himself. The few scenes you see of him doing this in the movie include him making similar remarks to the trope name.