[[DeathNote http://tvtropes.org/pmwiki/pub/images/Find_Kira_the_easy_way.jpg]]
[[caption-width:400:Why ''Death Note'' doesn't use this much.]]

-->'''Azula:''' So, I hear you've been to visit your Uncle Fatso in the prison tower.\\
'''Zuko:''' That guard told you!\\
'''[[ManipulativeBastard Azula]]:''' No. You did. Just now.
-->-''AvatarTheLastAirbender''

Ben is undercover. Stan, typically a [[TheRival rival or enemy]], knows or at least suspects as much; and tests his suspicion by blurting out Ben's real name. Inevitably, Ben will, quite unprofessionally, respond to the use of his name, confirming Stan's suspicions. Note that Ben's reaction is, in and of itself, sufficient to convict him, even if the two are alone and Stan could not possibly be addressing anyone else.

The trope operates independently of the good-bad alignment of either party.

The ploy used to force TheReveal need not be a name; it can be a specific word/phrase, or something spoken in the other character's native language. It can even be a non-verbal prompt, such as a familiar face, location, scent, etc. The point of the trope is that "Ben" is hiding something about himself, and "Stan" tricks "Ben" into revealing it by causing an automatic, unthinking reaction.

See also PullTheThread, SomethingTheyWouldNeverSay, BluffingTheMurderer. If Stan wasn't suspicious ''until'' Ben responded as Ben, it's SomethingOnlyTheyWouldSay. If Stan says something that only an impostor ''wouldn't'' be suspicious of, it's BluffTheImpostor.

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!!Examples:

[[foldercontrol]]

[[folder: Anime and Manga ]]

* In an episode of ''{{Yu-Gi-Oh}}!'' series 0, a cop announces that a criminal has been tracked to the joint where Yugi and Jyonouchi have gone for a burger, and their friends are working. The police sergeant says it might help that the crook is allergic to eggs; Anzu says (falsely) that he will be easy to catch, because the burger buns have lots of egg in them. At that, the crook freaks out and tries to bolt, despite having suffered no ill effects when he ate there the day before. In a subversion, this crook turned out to be a small-time shoplifter; the real perp did not fall for it.
* In ''DeathNote'', Light Yagami of all people is once tripped up by this ploy, when Namikawa tells him that he already knows that [[spoiler: Higuchi is the Yotsuba Kira]] - it's only a very strong hypothesis at this point, but Light's surprised reaction is all the confirmation he needs. Of course, Light is [[spoiler:under amnesia at the time]].
* Even Lelouch, TheChessmaster of ''CodeGeass'' is not immune to these.
-->'''Rivalz''': [Lelouch]'s even holding a household account book...
-->'''Lelouch''': How do you know about that?
-->'''Rivalz''': Huh, you really do?
* ''DetectiveConan'' used this early on, with Ran and Conan.
* The Novelization adds one of these to ''GundamSEED''. In the original series, when watching Kira fight, Andy quickly deduces that the Strike Gundam's pilot is a Coordinator. He later figures out that Kira is the pilot, most likely by watching his actions during a Blue Cosmos terrorist attack both are caught in. Realizing Kira is a both a Coordinator and not a native, and puts two and two together. He then confronts Kira in a scene which is played like he flat out ''knows'' what he is saying is true. In the novel, he suspects it (bases on his observations), but isn't quite sure, and uses one of these to confirm it.
* This is how Videl figured out that Gohan was Saiyaman in the ''DragonballZ'' manga.
-->'''Videl:''' So [[SecretIdentity your identity is a secret]], right?
-->'''Saiyaman:''' Uh, yeah. That's correct...
-->'''Videl:''' So, Gohan, how'd you get out of school?
-->'''Saiyaman:''' Simple! I just said I was going to the bathroom and got here as...''crap''.

[[/folder]]

[[folder: Comic ]]

* ''Lucky Luke.'' The cowboys have captured a Native American and try to question him, but the prisoner apparently does not speak English. Lucky Luke serves him a glass of whiskey and asks him if he'd like some rocks on it. "No, thank you", answered the soon-to-be official interpreter. This troper used this same trick during a RPG, btw.

[[/folder]]

[[folder: Film ]]

* Gene Simmons attempts this tactic against John Stamos in the movie ''[[http://www.agonybooth.com/never_too_young/ Never Too Young To Die]]''. In a subversion, Stamos manages to bluff his way out of the situation, though not convincingly:
-->'''Ragnar:''' Stargrove!
-->'''Lance:''' Is that name supposed to mean something?
-->'''Ragnar:''' My mistake.
* Subverted in ''[[JamesBond The World Is Not Enough]]'': Christmas Jones becomes suspicious of Bond, who is currently impersonating a Russian scientist:
-->'''Xmas Jones:''' (in Russian) Your English is pretty good for a Russian.\\
'''Bond:''' (also in Russian) I studied at Oxford.
** Note that she eventually penetrates Bond's ruse by remembering the scientist's actual ''age''.
* In ''[[JamesBond Die Another Day]]'', Bond uses this method to reveal the identity of Gustav Graves/Colonel Moon. The trope as played out here is somewhat less than effective, since the audience has already been alerted to this plot point.
* Similarly, in ''[[StarWars Revenge of the Sith]]'', Yoda confronts Emperor Palpatine with his Sith name. Again, the effect is muted by the fact that the Sith Lord is no longer really trying to hide his true nature, at least not from the Jedi.
** In ''[[JediAcademyTrilogy I, Jedi]]'', Corran Horn goes undercover as ''Keiran'' while training at Luke Skywalker's Jedi academy, changing his name since he's a mildly famous pilot. Interestingly, after leaving the academy "Keiran", going by yet another name, is [[BluffTheImpostor questioned about Luke]]. He goes on to display an appalling lack of knowledge about one of the single most famous and important people in the galaxy in order to keep up the ruse.
** In ''[[TheThrawnTrilogy Dark Force Rising]]'', when Mara Jade, a former assassin for Emperor Palpatine, meets with Grand Admiral Thrawn, he says "Come closer, Mara Jade." (The two had met several years before and she was under an assumed name.) She begins instinctively walking forward, catches herself and comments that Thrawn shouldn't have to rely on such cheap tricks to verify who she was. He agrees, and then asks her questions that only she would know the answer to.
*** Used again in the same book. No one in the New Republic knows the name of the new Grand Admiral on the scene. Han Solo meets with a ship thief who does know, and is offering to show Han the location of a lost fleet before the Empire finds it.
---> '''Han''': "What makes you think the Empire's involved?"
---> '''Ferrier''': "With Grand Admiral Thrawn in charge over there? He's involved in everything."
---> '''Han''': "Thrawn, huh? Thanks, Ferrier."
** In Zahn's ''OutboundFlight'', Thrawn is able to get an awful lot of information out of a Corellian guest/prisoner who really doesn't want to tell him these things by working this method into conversation, though he makes it look effortless and never actually says the trope name.
* In the Bond-wannabe film ''[=~Agent for H.A.R.M.~=]'', the lead character exposes the ersatz Bond girl as a villainous double agent by using her real name. The "even though they are alone in the room" clause, as stated above, applies here.
* In ''[[Comicbook/{{Superman}} Superman II]]'', Lois tries this to reveal Clark's secret identity, first by calling him "Superman" and then by jumping into Niagara Falls. Naturally, Clark manages to rescue her without being obvious.
** In the restored cut, she tries jumping out a window, with the same result. Then she tries something a bit more effective.
*** This itself is a YouJustToldMe, as [[spoiler: when she shoots him, he drops the mask and points out that if she'd been wrong, Clark would be dead. She then reveals that it was a blank.]]
*** [[{{Fridge Logic}} Superman can see atoms spin. How did he not know it was a blank?]]
* Straightforward example in ''[=~Who Is Cletis Tout?~=]'' Sloppy work on Finch's part to respond to his name, considering he was a fugitive in the middle of a room of cops.
* In the 1993 adaptation of ''TheFugitive'', U.S. Marshal Sam Gerard (TommyLeeJones) tricks fugitive surgeon Dr. Richard Kimble (HarrisonFord) into revealing himself when Gerard calls [[StairwellChase down a stairwell to a retreating figure]], "RICHARD!" Kimble involuntarily looks up, giving himself away.
* In ''TheGreatEscape'', one of the fleeing British [=POWs=] gives himself away when a suspicious Nazi officer offhandedly wishes him "Good luck!" -- in ''English'' -- causing the Brit to politely respond "Thank you". Made particularly egregious by the fact that the prisoners had previously run DRILLS on just this situation, before escaping the POW camp, and that this particular gentleman had admonished another prisoner for falling for that one.
** Justified as TruthInTelevision. The character who makes this mistake is the companion of the Escape's leader. In real life, this was precisely how the leader and companion were caught (including the fact that it was all the companion's fault).
** Parodied by ''That Mitchell And Webb Look'', in the German-speaking version of Numberwang: the host does this to one of the contestants.
* The above example also was used in ''SpiesLikeUs''. Agent Millbarge suspects that a pair of agents supposedly sent to help him and his partner are actually KGB agents. He confirms his suspicions by saying something funny in Russian, making one of them laugh.
* ''AustinPowers: International Man of Mystery''
-->'''Austin Powers''': Your boss, Number 2. I understand that cat's involved in big underground drills.
-->'''Alotta Fagina''': How did you know?
-->'''Austin Powers''': I didn't, baby. You just told me.
** Is this case Austin was aware of the fact ahead of time and was invoking this trope purely to look classy.
* In ''LegallyBlonde'', a lawyer outs a witness as gay (to prove he couldn't have been the female defendant's lover), by asking him several rapid-fire innocuous questions (like "How long have you worked for her?" etc.), ending with "And your boyfriend's name is?" which the witness answers without thinking.
** When he attempts to reestablish cover by claiming that he was confused by the rapid-fire way in which the questions were asked, and didn't realize he was being asked about a romantic boyfriend and that he's actually straight, his ''gay lover'' re-blows the cover by thinking he's telling the truth (since he is under oath, after all), and taking it badly.
* In ''MrAndMrsSmith'', John, already suspicious about his wife, "accidentally" drops an open bottle of wine that she catches perfectly; then she realizes his ruse and lets it spill.
* In ''BillyJack'', Billy uses this ruse to trick Jean Roberts into revealing that she was raped by Bernard Posner. Don't ask what tipped him off, I don't know.

[[/folder]]

[[folder: Literature ]]

* Done subtly in ''Discworld/TheFifthElephant''. The Patrician assigns Commander Vimes a manservant, Inigo Skimmer, for his trip to Uberwald. Vimes tosses an orange at him, and it bounces off. He doesn't say anything at that point, but later, when he reveals that he knew about Skimmer being a spy, he points out that a normal person would have either caught the orange or at least flinched (to confirm this theory, he later lobs one at Sergeant Stronginthearm, who ducks); Skimmer looked at it, recognized that it wasn't a threat, and let it go on its way, inadvertently showing that he has had assassin training.
** Played with a bit in ''Discworld/NightWatch'' too. Coates informs Vimes that "I know you're not the real John Keel." Vimes keeps a totally straight face, only to realize that that gave him away more thoroughly than anything he could have said.
* In [[IsaacAsimov Isaac Asimov's]] mystery novel ''A Whiff Of Death'', the killer gives himself away by reacting to the detective grasping and starting to turn a valve that had been rigged to cause an explosion (the trap had previously been detected and neutralized).
** In one of Asimov's short mystery stories, the culprit is a Québécois person using a false identity of an American. The detective tricks him into revealing his true identity by asking him to write the word "Montréal", and he writes it with an ''accent aigu'' on the e, whereas someone who only spoke English wouldn't spell it that way.
**Another story involves the classic thrown object, with the twist that the perp is the ''thrower''. He gives himself away as having spent a long time on the moon when he throws it ''far'' too short in normal gravity.
** In a third Asimov story, "I'm In Marsport Without Hilda", a detective is trying to figure out which of several people in a room is a drug smuggler. All of the innocent suspects are currently [[MushroomSamba loopy]] and speaking stream-of-consciousness gibberish, because they were given a drug to prevent space sickness, and the guilty party is faking it. Unable to figure out who is guilty, the detective, out of frustration, starts telling them about the hot date he would have had, if he wasn't stuck interviewing them. The guilty party's, um, [[IfYouKnowWhatIMean "reaction"]], gives him away.
** In ''The Robots of Dawn'', Baley has circumstantial evidence against the criminal, who is unfortunately a very respected member of society (on another planet), so his word carries more weight than his. So, after presenting the evidence, he says the man might have committed something worse as a side effect. The criminal shouts there could have been no such side effect to what he did...
* This is used a few times in the first book of Terry Goodkind's ''SwordOfTruth'' series.
** And then in the fourth, Kahlan appears to have learned the method - at least where girl talk is concerned.
* In Stephen Fry's The Liar, the main character tries to hide his identity from the police, only to respond his own name, which they got from the inside cover a book he had with him. This is based on His Fryness's own experience.
* Happens in {{Animorphs}}; Cassie (morphed as Rachel) is talking to a [[ThePuppetmasters Controller]], and he suspects her, so he randomly blurts out "Andalite!". If Cassie had reacted, she'd have given herself away, but she plays it cool and responds "Yeah, a light would be good too."
* This is the ''modus operandi'' of Vlad and Kiera in the ''{{Dragaera}}'' novel ''Orca''. They basically spend the whole book going around in various disguises talking to the conspirators, pretending to know more than they do (which is nothing} until they get a reaction, and then put all the pieces together.
* SherlockHolmes has used it at least once (in ''The Three Gables'').

[[/folder]]

[[folder: Live Action TV ]]

* The series ''KnightRider'' did this numerous times. On one occasion, a woman impersonated her recently murdered mother to flush out the killer; on another, a blind woman pretended to drive, suggesting to the criminals that she might have witnessed their deeds.
* ''{{Angel}}'', "Blind Date": Angel throws an object at a woman claiming to be perfectly blind; she catches it out of the air perfectly. Oops.
** Of course, she actually ''is'' completely blind, and he knows it... the point is how the court full of people react to this.
* In an episode of ''TheAgency'', an undercover agent has replaced a person who's known to be allergic to dogs, so he reacts accordingly whenever there's a dog in the room. He's discovered when his suspicious contact places a dog nearby but out of sight and he fails to develop a stuffy nose.
* In one episode of ''{{Monk}}'', the identity of a mail bomber is confirmed when he panics at the sight of someone opening one of his custom-made packages. He shouldn't have known about the bombings because he had been in a coma when they took place. (If you're curious about how he managed to set off the bombings while ''in a coma'', watch the episode in full.) In another episode, he cleared Willie Nelson's name by proving that the other suspect wasn't blind--he had a streaker run past her, and she reacted.
* From ''{{Dexter}}'':
-->'''[[ScaryBlackMan Doakes]]''': That's all you care about, is your job. Even if it meant doin' Pascal's man to get it back.
-->'''[[PointyHairedBoss LaGuerta]]''': How did you know about Bertrand?
-->'''[[ScaryBlackMan Doakes]]''': I didn't for sure until just now.
* ''{{Stargate SG-1}}'': This trope is used and parodied in the episode "1969". The team is stranded in a top-secret Air Force facility in 1969, and are suspected of being spies. An Air Force interrogator comes in and, in Russian, asks if they're Soviet spies. Daniel, who speaks twenty-three languages, replies in Russian, that no, they're not. Naturally, he's not believed.
* Used in ''JustGoodFriends'' where Vince has been unfaithful to Penny. Again.
--> '''Penny:''' Why did you take that girl home?
--> '''Vince:''' (Sigh) Who told you?
--> '''Penny:''' (sadly) You just did.
*In the ''{{Lost}}'' episode "The Cost of Living," Jack has seen x-rays and believes they are Ben's, so he questions him about symptoms. Ben's reaction gives him away. Later he asks Juliet why she told Jack about his tumor, to which Juliet replies that she didn't; Ben did.
*On ''{{House}}'', Foreman finds out about Thirteen's bisexuality this way.
**Earlier in the series, House is talking to an 18-year old kid who is taking care of his mother. He later puts an X-ray on the lightboard, and says he can tell the person is about 15. The kid confesses to lying about his age. After a brief conversation, House reveals that it wasn't even the kid's X-ray.
* [[SubvertedTrope Subverted]] in an episode of QuantumLeap where Sam leaps into the body of a blind musician, and maintains his sight. A woman becomes suspicious, thinking that the man had never been blind, but when she tries to out him by flicking a lighter in front of his face, he can't see it because he had just been temporarily blinded by a camera flash.
** A similar, more painful, subversion occurs on an episode of ''ArrestedDevelopment''. Michael tries to prove a blind woman is only faking her condition by [[ThrowTheBookAtThem throwing a book]] at her. Unfortunately, she's been temporarily blinded for real and the book hits her in the face.
* Happens during a manhunt in occupied Egypt, in ''Rome''.
-->'''Officer''': [Latin] Right, be off with you. (turns away) [Egyptian] Please bless us with your forgiveness, sacred majesty.
-->'''"Greek slave"''': [Egyptian] Granted, mortal.
-->(beat)
-->(fight scene)
* In one episode of the sketch show ''SmackThePony'', two women and one man are being held hostage alone in a room somewhere. One of the women tells the others that her name is some male one. This puzzles the second woman and she keeps asking for explanations for it, but the other just maintains it just is that way. Eventually we see the second woman whispering the other various female names while she sleeps, until she reacts to one and has to admit that was her real name all along; she was just fooling the others as a joke.

[[/folder]]

[[folder: Video Games ]]

* In ''[[SonicTheHedgehog Sonic Adventure 2]]'', Dr. Eggman uses this ploy to discern which of the two identical-looking Emeralds is the real one.
-->'''Eggman:''' You thought you could trick me with that fake Emerald, didn't you?
-->'''Tails:''' So... how did you know it wasn't the real one?
-->'''Sonic:''' ''(cutting him off)'' ''TAILS!''
-->'''Eggman:''' Heheh, because you just ''told'' me, fox-boy!
** I think he was just messing with Tails' head at that point; he knew there were two signals, and he had six of the Emeralds, so one had to be fake; logically, the fake one would be the one they were willing to give up.
*** Not to mention that Sonic's [[LargeHam tone of voice]], at least in English, made it pretty obvious that he was doing something tricky.
* In the third case of ''PhoenixWrightAceAttorney: Trials and Tribulations'', Phoenix uses a variation on this to trap a murderer: he claims that a vial of medicine that had the suspect's fingerprints on it [[spoiler: contained the poison that was used to kill the victim.]] Having no idea of its true contents, the suspect angrily refutes Phoenix's claim by [[spoiler: giving the description of the ''real'' poison bottle]] - something he could only have known if he was the murderer.
** Or if [[spoiler:he really had impersonated Phoenix in the first trial, and would therefore know the description of all the evidence gathered at that point. However, if he'd confessed to impersonating a defense attorney in a case for which he was a suspect, it's basically still confessing to the murder anyway.]]
* Used in FireEmblem Radiant Dawn. Heather, a small time thief, confronts Yeardley, a general working on Duke Ludveck's orders, about his attempts to get the townspeople of Crimea to revolt against Elincia.
-->'''Heather:''' So! You're the ones sent by Ludveck of Felirae?! You've been stirring up these little revolts all over the place!
-->'''Yeardley:''' What?! How did you know?!
-->'''Heather:''' I see things here and there. But half of it was just a guess! ...Judging by your reaction, though, it seems I was right.
** Later on, when Marcia confronts her useless brother Malakov as he tries to avoid fighting Imperial Army troops:
-->'''Marcia:''' ...I think I see. You owe them money, don't you? Isn't that the real reason why you don't want to see them, cheese breath?
-->'''Makalov:''' W-when did you learn to read minds like the herons!?
-->'''Marcia:''' I can't, you spineless sea cucumber! It's just so typical of you that I guessed!
* A variant where "Stan" doesn't let "Ben" know when he figures it out. In ''KingdomHearts: Chain of Memories'', Axel is sent to Castle Oblivion because Marluxia and Larxene are suspected of plotting against the Organization. About halfway through the game, Axel chats with Larxene about the plan they have for [[TheHero Sora]] as Larxene heads down to meet Sora.
-->Axel: "Don't forget. Sora is the key. We need him if we're going to take over the Organization."
-->Larxene: "I know that you're in on it too, but keep it under your hood. At least until the time is right."
-->Axel: *after Larxene leaves the room* "You would have been wise to do the same, Larxene."

[[/folder]]

[[folder: Web Comics ]]

* A creative application of the trope occurred in ''RipAndTeri''. Agent XI knows Rip has infiltrated a TV studio in disguise. A few days earlier, Rip had encountered XI in a janitor uniform, so XI stations himself inside the studio in the same uniform. Rip's startled reaction to seeing the same "janitor" he fought earlier gives him away.
* From ''{{Narbonic}}'', [[http://www.webcomicsnation.com/shaenongarrity/narbonic/series.php?view=archive&chapter=9924 during the D-Con]] StoryArc:
--> '''Helen''': You know I'm not "Dave Pretorius." There's no such man. You know I'm really your own daughter in disguise. You know I infiltrated D-Con to crack the Dave Conspiracy, having no idea you'd already done it!
--> '''Helen''': And you didn't actually know any of this until I voluntarily told you, did you?
--> '''Dr. Narbon''': I'm '''such''' a great mother.
* Used in ''EightBitTheater'' [[http://www.nuklearpower.com/2009/01/06/episode-1079-verbal-flanking/ here]].
* In [[http://www.krakowstudios.com/krakow/archive.php?date=20021227 this]] ''Krakow'' comic, Canadian rap sensation Snow tricks one of the characters into admitting that he altered the lyrics while singing one of Snow's songs.
-->Case: But...but...How did you know that?
-->Snow: I only had suspicions, but you just confirmed them!

[[/folder]]

[[folder: Web Original ]]

* In ''[[ShadowOfTheTemplar High Fidelity]]'', after Simon tells Sandra that [[spoiler:he's going to Europe to find [[DatingCatwoman Jeremy]]]]:
-->'''Sandra:''' [[spoiler:I could believe this stupid shit from Mike, but I never thought I'd catch you thinking with your dick!]]
-->'''Simon:''' [[spoiler:...what?]]
-->'''Sandra:''' [[spoiler:You heard me!]]
-->'''Simon:''' [[spoiler:Christ, does ''everyone'' know about [[SecretRelationship it]] by now? How long have you known?]]
-->'''Sandra:''' [[spoiler:Known for sure? For about-- ''(checks watch)'' --ten seconds.]]
-->'''Simon:''' Oh Jesus, I walked right into that, didn't I?

[[/folder]]

[[folder: Western Animation ]]

* In Disney's ''Disney/{{Aladdin}}'', Jasmine, suspecting "Prince Ali" to be Aladdin, idly mentions Aladdin's friend/pet Abu (whom "Ali" would not know about); Aladdin responds without thinking.
* ''TheIronGiant'': Annie Hughes is talking to junkyard owner Dean [=McCoppin=]. She mentions Hogarth (her son) sneaking out to the junkyard, and he asks if she knew about it, and she says "I do now".

[[/folder]]

[[folder: Real Life ]]

* Shouting "Attention!" is one method of revealing if someone has military training (an FBI agent did this while interrogating a suspect in the 1998 Nairobi bombing). Shouting "Achtung!" unexpectedly was used among allied Prisoners of War to uncover German infiltrators.
* To tell if someone speaks a language or not, police often ask them to say what color different words are (like a green colored "red"). People who speak the language will take far longer.
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