Bluff The Impostor / Live-Action TV

Bluffing the Imposter in Live-Action TV series.

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• A short-lived spy series in the sixties had the hero pull a Dead Person Impersonation of a wealthy man who'd been killed by Soviets when they mistook him for the spy. The rich man's wife caught on to the imposter fairly quickly, because her husband was a Jerkass, and the agent treated her with courtesy. She tested him by asking if he'd consulted his sister about a certain business dealing. Not having had the chance for a proper briefing about the man he posed as, he said dismissively, "What does she have to do with it?" Of course, "My husband doesn't have a sister." She wound up covering for him anyway.
• Agents of S.H.I.E.L.D.:
  • In "Face My Enemy", Agent 33 disguises herself as agent May to lure Coulson into a trap. When Coulson gets suspicious, he casually asks 'May' if they could finally get that cup of coffee they discussed years earlier when this mission is over. When May agrees, Coulson knows enough; the real May hates coffee.
  • In "Love in the Time of HYDRA" this happens again, this time Agent 33 vs Talbot. To be fair, Talbot realizes very quickly and notifies Coulson "The nanomask is in play", and assembles all female staff workers, even telling his security not to let anyone disturb him, even if it is him. He even knows a lot about his staff, knowing which lines to say and how they should respond. However, he fails to realize that 33 can adopt either gender; or believed they were restricted to one gender, as when he himself was impersonated, it was by a man whom he knows is in custody.
  • In "Code Yellow", Deke figures out that something is off about "Coulson" when Sarge says that Deke's grandparents are "slowing down" (not realizing that they're in their thirties due to time travel), so he asks about Agent Doug. None the wiser, Sarge keeps it circumspect: "Doug's Doug". Unfortunately for Deke, Sarge also recognizes that Deke just played him and drops the pretense.
• Alias: It seemed to happen quite a lot, due to all the spies, moles, and infiltrators, but mostly due to Project Helix, an Applied Phlebotinum that allowed one person to be identical to another. Will Tippin held a gun on Sydney Bristow because he thought her to be an impostor. He asked her what he spilled on his shirt a decade ago before a job interview and she knew. Similarly, Sydney realized Francine had been killed and replaced with a gene-disguised impostor when she accepted a bite of coffee ice cream, which Francine hated.
• Batwoman (2019):
  • Kate's father, Jacob, seems to have quickly forgiven her stepmother, Catherine, for a major betrayal. This is out of character enough to make Kate suspicious, so she calls Jacob on the phone and reminisces about the snowstorm on the day he married Catherine. The impostor doesn't know that the wedding was on a hot summer day.
  • Tommy Elliot (aka "Hush") uses the same technique to look like Bruce Wayne. Already suspicious of "Bruce" acting odd, Julia asks if Bruce just came from seeing her father, Alfred, at his lake house in Glasgow. When Bruce confirms it, Julia knows he's a fake as her father lives in a flat in London.
• One episode of Big Wolf on Campus uses this trope to help the two main protagonists distinguish between who is or isn't possessed by a vengeful ghost out to murder the main hero. When sidekick Merton Dingle is possessed, Tommy Dawkins is able to figure it out after Possessed-Merton fails to remember the secret word that lets them know if he's possessed or not.
• Averted on The Blacklist as Liz is undercover as an arms dealer from Harvard at an illegal auction. One of the leaders is suspicious and asks her about "the Duckie". Liz bides time by faking a sneeze. Luckily, Red is nearby and covers by complaining about "the Duckie" being the train that took drunken Harvard grads about. He then acts like he and the woman Liz is impersonating go back a long way to solidify her cover.
• Burn Notice:
  • Michael, in one of his many voiceovers, mentions that the risk of falling prey to one of these is the reason why spies avoid assuming other people's identities whenever possible... and that, if you do have to do it, it helps if the other person is scared to death of the one you're pretending to be.
  • Season Two episode "Truth & Reconciliation" has him as the bluffer instead of the imposter, noting in his voice-over that if someone is asking for information, it's basic security to do this to ensure they're who they say they are and it's a pretty good tactic:
    Michael: Gustavo, we talked about this on the phone. I'm giving you eight thousand dollars for a file. Part of what that money buys is privacy.
    Contact: (with accent) I don't care what I said on the phone. You don't tell me what I want to know, you don't get this file. Eight thousand, no eight thousand.
    Michael: The deal I made with Gustavo was for ten thousand dollars, not eight thousand dollars. He was very clear about that number. And we never talked on the phone. You wanna tell me who you are?
    Contact: (smiles and drops the accent) I can explain. (pulls a knife on Michael)
• Charlie's Angels:
  • In the pilot for the original series, Kelly Garrett (Jaclyn Smith) was masquerading as a long-lost heiress. She met up with Aram Kolegian (Tommy Lee Jones), who had known the heiress before her disappearance. He casually mentioned several things to her about their past which she agreed with. After she left, he said to himself that he didn't know who she was, but she sure wasn't the heiress because the things he had said were lies.
  • Subverted earlier in the episode, when an old friend of the family tries to bluff Kelly with stories of her (well, the girl she's pretending to be) childhood littered with incorrect details. Kelly, however, corrects each mistake and calls him out on what he's doing rather quickly.
• On Charmed (2018), Michaela is at first happy her adoptive mother has dropped by for a visit but suspicious of her behavior. They have a talk as Michaela says "I'll always be your little Baa-Baa-Boo" and her mother embraces as if it's an old childhood nickname. Too bad for her Michaela made the entire thing up on the spot so knows this is an imposter.
• On Chilling Adventures of Sabrina, Ambrose is being held prisoner and falsely accused of murder by some nasty witches. Hilda comes to see him and is met by a calm Ambrose who talks of how he deserves what's happening to him and Hilda can't help. Meanwhile, the real Ambrose is being met by a witch using a glamour to pretend to be Hilda and press Ambrose to confess to save the family. Each of them is able to see something is wrong and test it. First, Hilda talks of a party they had last year for the death of Zelda’s Familiar Vinegar Tom, Ambrose agreeing it was great... and Hilda stating that Vinegar Tom died in 1989. For his part, Ambrose says he'll be happy to confess... as soon as "Hilda" tells him what her favorite episode of Fawlty Towers (a show she's never watched) ^note  Hilda Hates Fawlty Towers. is. Both impostors realize they've been found out.
• Played much less seriously in the pilot of The Chicago Code. Wysocki asks his partner what time the game starts, and Evers tells him 1:20. Wysocki notes that the White Sox have the day off, which blows Evers' cover revealing himself for the traitorous Cubs fan he truly is.
• On Designated Survivor, Hannah is investigating a brewery outside of Boston with the owner talking of having grown up in the area and brushes off knowing of anything with a genetic company. Hannah says he should get "Gronk" to promote his beer, the man blinking in confusion before she clarifies she meant New England Patriots star Rob Gronkowski. As Hannah tells her British partner, there's no way someone who grew up in this area could not be a die-hard Patriots fan.
• Doctor Who:
  • In the eponymous final episode of "The Keys of Marinus", Ian Chesterton notices that "Arbitan" (actually Yartek, the leader of the Voord, who killed him at the end of the first episode of the serial) is behaving very suspiciously, including not seeming to recognize Altos, who he sent to retrieve the keys before the Doctor and Companions, so he gives him a fake micro-key that they also acquired on their travels instead of the real one — the real Arbitan created the keys and would be able to spot the slight flaw that distinguishes it from the real ones, but an impostor wouldn't know the difference.
  • In "The Android Invasion", the Doctor realizes he's dealing with a Sarah Jane android when she accepts some ginger beer, the real Sarah Jane having told him earlier that she can't stand the stuff.
  • In "The Caves of Androzani", General Chellak is running a war against Sharez Jek and his army of highly lifelike androids. One android happens to be impersonating a subordinate officer, Major Salateen, which is passing intelligence on to Jek. Chellak only gets wise when the real Salateen, who had been abducted by Jek, turns up out of the blue. Rather than report the security breach and suffer the consequences, Chellak takes Salateen's suggestion to feed disinformation to the android.
    • but foiled when the android Salateen detects the presence of the real Salateen, allowing Jek to counter-bluff and sabotage Chellak's assault on his lair.
  • Martha uses this on her roommate Jenny in "Human Nature". As it turns out, Jenny has been possessed by an alien lifeform; the alien's responses to Martha's conversation confirm that not only is she not really Jenny, she's not really human.
    Martha: Would you like some tea?
    Jenny: Yes, thanks.
    Martha: I could put a nice bit of gravy in the pot. And some mutton. Or sardines and jam, how about that?
    Jenny: I like the sound of that.
    Martha: Right. Hold on a tick. [discreetly flees]
  • "The Sontaran Stratagem"/"The Poison Sky": The Doctor uses this on the clone who has replaced Martha by doing things like saying "Avanti" instead of "Allons-y!" and asking her if she's called her family to warn them about the poisonous gas. Subverted since the Doctor knew from the start that this was a Sontaran clone and was using her to his advantage.
• Family Matters: Urkel is the captive of a man impersonating Carl's partner. Carl hears him talking through the door and not giving the standard reply of, "Not if I see you first," when he says, "See you later." Carl baits the kidnapper by sliding money under the door that he doesn't owe him and breaks it down when he comes to get it, then apprehends the felon.
• The Grand Finale movie for The Famous Jett Jackson has the titular character swap places with his secret agent Show Within a Show character Silverstone. At the time, the show Silverstone was dealing with a new Big Bad (Michael Ironside) with the ability to disguise himself as any person, and Jett (the actor) has to figure out a way to defeat him. Suspecting that the Big Bad has infiltrated the spy agency, Jett demands Silverstone's mentor sing him the song he sang Silverstone as a baby. While the mentor sings "The Itsy Bitsy Spider", Silverstone's partner starts slowly moving towards the dimensional key. Jett catches her hand and has the mentor invoke this trope. The question is about the name of the plant he gave her for her birthday. She replies that she doesn't have one for it. Of course, there is no plant, and she is the Big Bad in disguise.
• In an episode of Farscape where Crichton believes he has returned to Earth, the alien masquerading as his father pulls one of these. In a later episode, when Crichton really has returned to Earth and meets his father, Crichton references that conversation.
  • In "Losing Time" an energy being possesses one of the crew. The second being chasing it tells them that the impostor won't know deep personal details about the host so they should question each other to see who can't answer. When questioned Chiana is evasive but eventually confirms her brother's name and corrects D'Argo when he tries to trick her with false information about her past. Jool on the other hand struggles as nobody knows her, and admits the story she initially told them was a lie. Turns out the whole thing was pointless, the energy being was possessing Chiana long enough to learn the personal details they questioned her on.
• In an episode of The Flash (2014), Cisco and Caitlin try to bluff Laurel's Earth-2 double Black Siren by pretending to be their own Evil Doppelgangers Reverb and Killer Frost, respectively. It seems to work at first, then Black Siren tosses a random object to "Reverb". Cisco catches it, only for Black Siren to reveal that all doppelgangers from Earth-2 have a different dominant hand. It's also possible that she's aware that the real Reverb and Killer Frost have been killed by Zoom. This ends up being forgotten in future episodes, as the presence of multiple parallel Earths makes that nonsensical.
• Subverted on First Wave. Cade is met by someone who looks like the uncle who raised him but is suspicious he's a Gua imposter. He talks of his uncle helping Cade cope after her was cut from the school hockey team and without missing a beat, the man laughs "what are you talking about, you won them the championship!" As it later turns out, Cade was Properly Paranoid as this is a well-informed imposter.
• Frasier. Roz discovers she's pregnant, and Frasier encourages her to find the father and tell him the news. She claims one morning at Café Nervosa that the father was an architect, and not much else. Later, at Frasier's apartment, she mentions that he was an archaeologist, and Frasier gets her into the kitchen to pull one of these off the bat by asking her how the two met again.
  Frasier: This morning, you said you met him on a double date.
  Roz: Oh yeah, it was on a double date!
  Frasier: THIS MORNING YOU SAID NOTHING!
  • After Daphne finds out that a patient of Niles' has a crush on him, she and Roz go to her office to find out what she looks like. When they meet the woman, Roz rants about how they "flew in from corporate for a meeting", only to have the woman bluntly ask, "How could you fly in from corporate? Corporate's downstairs."
• On Fringe, Peter eventually uses this on Fauxlivia, reciting a line of Greek to her that the genuine article would have recognized. Unfortunately he wasn't very subtle about it, and she was waiting in the next room with a gun.
• FullHouse, subverted in the last episode of Season 8 since used to check the character's wellbeing rather than uncovering an impostor: Michelle falls from a horse and gets amnesia for a week (trying to play along as if recognising everyone normally) but then gets her memory back. Unlike other relatives, Danny and Joey both asked her trick questions — what day does Danny always vacuum the stairs and what's the capital of Nevada? Michelle correctly answers that stairs are vacuumed every day but doesn't know the capital — just as always. Her memory's back!
• Game of Thrones: Brienne is on a secret mission to exchange the captured Jaime Lannister back to his family in exchange for both of Catelyn Stark's daughters. Along the way they run into some Stark soldiers, and one of them recognizes Jaime. Brienne tries to claim Jaime is a common thief she caught and is bringing to justice, but the leader of the soldiers upends the ruse by demanding they both say his name at the same time. Naturally the two hadn't bothered to think of an alias ahead of time, so Brienne has to fight her way out of it.
• The Gemini Man: Used by Intersect Agent Sam Casey on Dr. Hale, who is supposed to be in the trailer of the truck Sam is driving, but suspected of being in the helicopter that's been following the truck the entire episode (which he is). Dr. Hale has rewired the intercom in the back of the truck to communicate with a radio unit in the helicopter.
  Sam Casey: Sorry about that last bump, Dr. Hale. I hit a hole in the road.
  Abbey: (trapped in the back of the truck) What bump?
  Sam: I hope it didn't jar you too badly.
  Dr. Hale: Uh, well it almost knocked my glasses off, but that isn't important. We have to make up that lost time.
• A General Hospital storyline had a woman named Katherine Crawford coming to town, claiming to be friends with the recently deceased Dominique Baldwin and rapidly befriending her widowed husband, Scott after learning that Dominique was dead. However, Scott's friend Lucy was immediately suspicious and began to investigate. Her first discovery, that no one named Charles Crawford had died recently (Katherine was claiming to have been recently widowed herself) was thwarted when Katherine stated that her married name had been Reynolds. But her second attempt proved successful when she was able to present the real Katherine Crawford to Scott. Unfortunately, Scott decided to believe Katherine's lame excuses, leading Lucy to have to make another discovery to prove Katherine's duplicity—upon re-reading the letter than Katherine wrote to Dominique, she realizes that Katherine used her fake name, something that would have been unnecessary if Dominique knew her. Which meant that Katherine ALREADY knew that Dominique was dead before coming to town, and that her intent from day one was to scam Scott out of the money that he'd inherited.
  • From the same show: Twice, Serial Killer Ryan Chamberlain escaped from prison and took his twin brother's place in Port Charles society so that he could continue to stalk Felicia Jones, who he was obsessed with. In both cases, Kevin managed to alert people by discussing events that Ryan couldn't have known about.
• A case of bluff the witness is used in The Good Wife episode "Unprepared". Once they realize the witness is the one who committed the crime (he claimed he made a cell phone call in an area with a phone block), they ask if he made the call during the intermission of the recital he was at. He says he did, and they point out that there was no intermission.
• Heroes: When Peter is controlling the body of Jesse, one of the Level 5 villains, Knox, his fellow escapee, catches him this way by asking "Jesse" if he can't wait to see his family and friends in Detroit, when Jesse's family is from Vegas and he doesn't have any friends.
• Hogan's Heroes
  • The crew is trying to decide if their most recent addition is truly a POW or a spy. Hogan tells his men not to ask about Ty Cobb's batting average as that's the first thing a spy would learn. Later on, after correctly answering questions on American cities, Carter asks the spy if he knows anything about Ty Cobb, to which the spy asks "Want to know his batting average?"
  • In another episode, one of Hogan's crew is trying to infiltrate a meeting of German officers under guise of another visiting officer. One of them, perhaps sensing an impostor, says he had heard that he injured his hand in a hunting accident, and asks him which hand it was: the right or the left? The spy manages to dodge the question by saying: "Thanks to superior German medical techniques, you can't tell which of my hands was injured!"
  • In the pilot episode, Hogan and his men test incoming escaping POWs this way first by asking what unit they're supposedly from, then feeding them some fictitious names while asking how Hogan's "old buddies" in the unit are doing. Carter passes handily, while a German infiltrator is later tripped up by replying that "Major Campbell" is doing fine.
• Kamen Rider Blade had a variation on this in the Hyper Battle Video, where a Trial has impersonated Kazuma, and subsequently Blade. Hajime roots out the Trial by calling out Kazuma's name; after the battle, he explains that the Trial reacted first because of its superhuman reflexes, to which Kazuma responds "That makes me sound kind of slow, doesn't it?"
• Knight Rider
  • Michael Knight finds that the villain with Latex Perfection is not Devon by calling him Ishmael, which confuses him. Earlier in the episode, Devon had greeted Knight quoting the beginning of Moby-Dick: "Call me Ishmael".
  • In another episode, when a girlfriend expresses concern about her father's behavior (he's been kidnapped and replaced with an impostor), Michael chats with him about the Disneyland tickets he had supposedly asked him for. When the man responds enthusiatically, Michael and the girl know he's a fake — they had never made any such plans.
• In an episode of Lie to Me, Cal and Torres visit a fertility clinic, posing as a married couple looking for an egg donor. Cal asks if what they've been told is possible, namely that his "wife's" infertility is due to an estrogen imbalance caused by the Coriolis effect, and the doctor agrees that it's a definite possibility. Had he been a real doctor, he would have known that the Coriolis effect has nothing to do with medicine.
• In a Law & Order: Special Victims Unit episode, when a man claims to have been watching a ball game as an alibi, Stabler starts chatting about how lousy the game was, only for the confused man to tell him that the game went well, thus confirming that he's telling the truth.
• Averted in season 5 of Lost when Pierre Chang realises that Hurley is probably from the future. Hurley blows his cover when he mistakes a straight question for a bluff.
  Chang: What year were you born?
  Hurley: 1930.
  Chang: So you're 47 years old?
  Hurley: Yeah.
  Chang: And you fought in the Korean war?
  Hurley: There's no such thing!
• On Magnum, P.I. (2018), Magnum is sent on a secret mission with a pair of CIA operatives. From the start, he senses something is off and talks to one agent on a "Neil Diamond fiasco, you must have read my file on it" and the man says he did and hopes this isn't a repeat. Magnum then talks to the nervous tech guy on how he trained at Hammond Air Force base and a diner with bad food nearby. When the two try to pull a double-cross, Magnum relates he was onto them from the start as there was no "Neil Diamond" mission and that diner doesn't exist.
• In Merlin, Arthur does this to goblin-possessed Gaius. Arthur offhandedly mentions Merlin's upcoming execution; when "Gaius" is completely nonplussed, Arthur immediately knows something is wrong.
• The Middleman: The Middleman is being possessed by an evil genius. Ida, warned by Wendy, innocently asks if there's anything he needs from her before she goes home to her husband and children. The fake Middleman, not knowing that Ida is an android, doesn't suspect a thing.
• In one episode of Misfits, Jess exposes an impostor by casually asking the character in question about the new car he doesn't have.
• Monk:
  • In "Mr. Monk and the Airplane," Stefan Chabrol has had his wife killed and replaced with his mistress. Unfortunately, a family friend of Barbara's happens to be on the plane with them, and figures out she's not who she supposedly is.
  • In "Mr. Monk Visits a farm" Monk goes undercover as a Mexican worker at the farm of murder suspect Jimmy Belmont. Belmont quickly becomes suspicious of Monk, approaches him and asks him a question in Spanish (which Monk isn't that fluent in). Monk just replies "Si, si" to Belmont's test question.
  Jimmy Belmont: I just asked if you got a squirrel in your pants.
• Murder, She Wrote
  • In an episode, Jessica becomes suspicious of a man's claim of having been in the armed forces. To that end, Jessica asks if he served in X division with her husband Tom. The man readily claims that he did and describes Tom as a fine soldier and one that he admired and respected. Of course, Jessica knows he's lying as her husband's name was NOT Tom, and he served in a different division of the armed forces than the one she named. However, she doesn't confront him with this, nor reveal it to anyone else, knowing the man could easily Hand Wave it as an honest mistake rather than an outright lie.
  • In another episode, she pulled a similar stunt with a professional chef, asking him about a favorite recipe of hers, claiming it was a pork dish with Bearnaise sauce. This tripped up the chef because the dish in question was actually salmon. The chef was then forced to confess that he did not graduate from cooking school, which tied in with a possible motive for murder at the restaurant where he worked.
• In an episode of NCIS: Los Angeles, Sam and Callen are kidnapped and trapped in a warehouse. They escape and shortly after run into a man claiming to be an abducted NSA agent. Sam secretly decides to test him by asking him which way he exited NSA HQ the day before. The man answers with a route that Sam knows is blocked by construction, revealing that he's an impostor. Sam lets Callen know via Trouble Entendre, and they secretly turn the tables on him.
• In Outlander, Claire tries to bluff Jack Randall into releasing her by claiming that she also works for his patron, the Duke of Sandringham. She tries to remain vague when Randall asks her if she met the Duchess, saying that she got her orders by letter, but she's still foiled because she doesn't know that the Duke never married.
• In Oz, Adebisi asks undercover cop John Basil about various criminals "Desmond Mobay" should know if his identity is genuine. He slips in a name that Basil doesn't recognize, and Basil either knows he's bluffing or suspects he might be.
  Desmond Mobay: I never heard of that guy.
  Simon Adebisi: That's because I made him up.
• In an episode of Painkiller Jane, Jane is set up by a wild scheme to give away the location of her team's secret headquarters. Part of the plot has her "rescued" by a shapeshifter posing as her best friend, Maureen. When Jane notices the woman doesn't have a recently applied tattoo, she talks of how she forgives Maureen for sleeping with a classmate in college. Later, after the shapeshifted is captured, they talk as it turns out the guy was the class geek and thus Jane knew it wasn't the real Maureen.
• In the Poirot episode "Hickory Dickory Dock", one of the students professes to be an expert in Keats. When Poirot quotes some poetry at her she assures him that he certainly knows his Keats. The only problem is that it wasn't a Keats poem.
• The Prisoner (1967)
  • Episode "The Schizoid Man": After a Village agent surgically altered to look like #6 is killed, #6 attempts to masquerade as the agent to escape. Unfortunately, he talks too much and makes several mistakes, causing #2 to become suspicious. #2 mentions someone named Susan saying something "only a month ago": #6 doesn't react. He asks #6 to "give Susan my regards" and #6 agrees. Later, after #6's escape has been foiled, #2 tells him that Susan died a year ago.
  • And depending on which episode order you prefer, there's also #6's reaction to #2's mention of "the General" as if he's talking about a person; another episode is about a supercomputer by that name.
• Probe:
  • "Black Cats Don't Walk Under Ladders (Do They?)": During The Summation, Austin uses the killer's own knowledge against them, causing them to believe that they've been affected by the same poisoned tea that was used to kill Marty Corrigan. He has to do it because until the killer confessed, he wasn't sure which of the suspects had done it.
  • "Now You See It....": At the climax of the episode, Austin James has recreated the murder method that was used to kill the previous two businessmen. He confronts his prime suspect with the situation (which includes an empty elevator shaft covered by a Hologram) and tricks him into confessing. The murderer does, but then tosses Austin down the empty shaft. Serendip's CEO and several police come out from around corners to arrest him. (Austin is fine, having anticipated this, lying safely on a crash cushion.)
  • "Plan 10 from Outer Space": Because he didn't have any evidence to determine if Trish or Helga committed the murder, Austin has to trick the murderer into confessing, by using the victim's sunglasses, which he says created a photonegative when the victim was electrified. When the murderer sees herself on the wall, she immediately starts trying to defend herself.
• In an episode of Promised Land (1996), a photography teacher becomes suspicious of the quality of the project a student has handed in and proceeds to ask him several questions in photographer lingo. Bristling at the implication, the student proceeds to not only answer him fluently, but even offer answers that he didn't ask for, thus proving that he alone worked on the portfolio.
• Red Dwarf
  • In "Balance of Power", Lister suspects that the Kochanski that visits him during his chefs exam is a fake when she uses the phrase 'up-up-up the ziggurat, lickety split' - something Rimmer has said before onscreen. To test 'her', he brings up them having had sex behind the bins on the snooker, which never happened, and causes Rimmer to blurt out that Lister never told him that.
  • In "Psirens", to differentiate between Lister and a shape-shifting, brain-eating Psiren, the rest of the crew got them each to play the guitar. Lister incorrectly believed himself a guitar god, so the Psiren played excellently. The crew then knew which one to blast. Although after hearing how the real Lister plays, they wanted to shoot him too.
    Cat: Little survival tip, bud. Never play your guitar in front of a man with a loaded gun.
• Revenge: Victoria invites the fake Amanda Clarke to tea and serves strawberries. When "Amanda" eats them, Victoria recalls her having had a severe allergic reaction to strawberries as a little girl. "Amanda" claims to have grown out of the allergy, but Victoria now knows she's an impostor because she made up the whole thing.
• Sanctuary: Will and Helen are among the survivors of a plane crash who are being picked off one by one by a creature that can create visual illusions. They know the creature can make itself appear to be one of the survivors, but they don't know who it is. The creature lures Will out of the plane and takes on his appearance. Helen catches it when, as Will, it offers her a cup of tea and she claims to prefer coffee; the real Will would have known that Helen hates coffee.
• In an episode of Sliders, Quinn impersonates his double until the double's friend and villain of the week successfully bluffs him. Quinn accepts the man's invitation to go sailing; unfortunately for him, he didn't know his double was terrified of water.
• Stargate:
  • Stargate SG-1
    • In an early episode, this was used to determine whether an elderly alien really was Daniel as he claimed he was. (He was)
      Jack: What color dress was your sister wearing when I took her out last night?
      Daniel-in-Ma'chello-body: I don't have a sister, and if I did, I'd never let her go out with you.
    • Played with in "1969", when the team has traveled back in time and are assumed to be spies. Not trusting their American accents, the interrogator asks Daniel Jackson, in Russian, if they are spies. Daniel answers "no", but instinctively switches to Russian as well. O'Neill is rightly annoyed.
  • Stargate Atlantis: In the season 5 premiere: Sheppard does this to the people coming to dig him and Ronon out from the rubble of Michael's collapsed base. First he asks if "Harris" is there, and when someone replies in the affirmative, Ronon remembers that Harris is on leave. Then Sheppard offers to buy the rescuers drinks when they get back, asking one if he prefers Duff Beer or Oprah Ale. From the rescuer's obliviousness to the fact that those are fictional beverages, Sheppard and Ronon conclude that their "rescuers" are really Michael's half-Wraith mooks.
• Star Trek
  • Star Trek: The Next Generation:
    • In "The Arsenal of Freedom", a simulacrum of a Starfleet captain unquestioningly accepts Riker's claim that his ship is called Lollipop ("It's a good ship").
    • In "Conspiracy", an old friend of Picard's does this to Picard because of alien parasites taking over the minds of Starfleet officers, which is explained when Picard asks his old friend what the hell he's talking about.
    • Likewise, in "Allegiance", Picard mentions a recent, still-classified incident in front of a fake Starfleet cadet, knowing that a real one would have no way of recognizing the comment as anything but a meaningless name.
  • Star Trek: Deep Space Nine: In the episode "Inquisition", while Bashir already suspects that things aren't what they seem, he proves it to himself and his captors when he asks what happened to O'Brien's shoulder, previously injured playing racquetball. O'Brien says it got better; Bashir then says it wasn't dislocated during a racquetball game, but kayaking. Holodeck room appears, Bashir's interrogator congratulates him on seeing through the illusion.
  • Star Trek: Voyager:
    • In "In the Flesh", having visited a functioning, holographic replica of Starfleet Academy built by aliens, Janeway reminisces about the real academy so she can casually drop in an inaccuracy to see if Chakotay has been replaced by an impostor. Chakotay is the real deal and is slightly offended.
    • In "Renaissance Man", Chakotay makes up an incident he claims Janeway told him about. When "Janeway" claims the current crisis has nothing to do with that past one, Chakotay knows that she's a fake. (It was the Doctor being forced to act as The Mole.)
  • Star Trek: Picard: While trying to ascertain whether Captain Tuvok is a Changeling, Seven of Nine mentions the game kal-toh. Tuvok's response seems to reassure her, then she suggests that she and Tuvok meet at Aklion VII, where she had a procedure done to stabilize her neural pattern. Tuvok readily agrees...which immediately exposes him as a Changeling, as a Vulcan would never willingly set foot on that planet after anti-Kolinahr demonstrations, and her neural pattern was actually stabilized by a mind-meld with the real Tuvok.
• Stranger Things: Upon the discovery of Will Byers' "body", Hopper becomes suspicious of the many additional goings-on of the case, like the local coroner being sent home so someone "from state" can do the autopsy, or the location of the "body"'s discovery. So he talks to O'Bannon, the trooper who called it in.
  Hopper: So that quarry, that's, uh, that's state-run, where they found the boy, huh?
  O'Bannon: Yeah.
  Hopper: [dry chuckle] Yeah, well, that's funny. 'Cause, you know, I know for a fact that it's run by the Sattler Company.
  • So Hopper goes to the morgue and tries to bluff his way past the Indiana State Trooper guarding the door. The guard's insistence that he doesn't work with the trooper who called in the "body" leads Hopper to realize he's an imposter.
  State Trooper: Hey, you can't be back here!
  Hopper: Yeah, I just got off the line with O'Bannon. He said that he needs to see you at the station. It's some emergency ...
  State Trooper: What the hell are you talking about? I don't work with O'Bannon.
  Hopper: Did I say O'Bannon? I meant ...
  State Trooper: (vacant, hostile staring)
  Hopper: [grimaces] Okay. (punches the trooper out cold)
• Supernatural:
  • In the episode "The Great Escapist", Properly Paranoid Kevin Tran grows suspicious when the apparent Winchester brothers forget the secret knock and sends them to get him takeout barbecue. When they obey with proper deference to a Prophet of the Lord, Kevin knows that they're Crowley's Mooks in disguise and sends them into a trap.
  • Double subverted in the much earlier episode "Skin". Sam suspects that a shapeshifter they're chasing is posing as Dean. He asks a supposedly casual question that's pretty obviously a test. The shapeshifter has access to Dean's memories and answers correctly, so Sam tosses him the car keys. However, the question was a red herring; the real test was the keys, which "Dean" caught with his left hand despite the real Dean having an injury to the left shoulder.
• In the season finale of Teenage Bounty Hunters, Sterling is with their rich mother, Debbie who says they have to leave town over her past crimes. Sterling then gets a text from sister Blair saying she's with Debbit at their house. Sterling carefully asks "what happens with Queso" and without hesitation, Debbie says Blair and their father will bring him along. Sterling literally screams "our dog's name is Chloe, who are you?!" In reality this is Debbie's twin sister Dana...who also happens to be Sterling's real mother.
• A storyline on Third Watch had the cops are searching for a pair of rapists who pose as police officers so that they can pull women over and then assault them. At the episodes end, as the fake cops are menacing a woman, the real cops arrive. The fake cops try to claim that the woman's screams for help are just the raving of someone high on drugs. Already suspicious (they know the woman and know she's not an addict), one of the real cops asks the fakers a question in "cop lingo". When he's unable to answer, they instantly know they've caught the criminals.
• In Tokusou Sentai Dekaranger, Hoji and a Monster of the Week switch bodies. Ban figures it out by calling Hoji "aibo" (partner). The real Hoji always says "Don't call me 'partner!'" but the villain didn't know that.
• Once in a while on the game show To Tell the Truth, a panelist will ask an obtuse question to the challengers that sounds like it has something to do with the subject matter, only to find after the voting and reveal that it really didn't. Just to see if the impostors (or the real person) would give an answer.
• In Twin Peaks, Audrey Horne is caught out this way when she fakes her resume at One-Eyed Jack's.
• One episode of the 2009 V series has Erica out James May's girlfriend as an undercover V agent using this method. They were engaging in small talk about (among other things) where she went to college, and Erica deliberately referred to the wrong football team, which exposed the alien when she failed to correct the error.
• In the second episode of Waco, Koresh, suspicious of his new neighbor who claims to be a rancher, asks him a question about cows. Vazquez, who is a government agent and not a rancher, fails to provide a good answer, tipping Koresh off that he's not who he says he is.
• Artie does this in an episode of Warehouse 13 to prove that Myka is really Alice Liddell, who has somehow swapped with Myka using a disco ball (It Makes Sense in Context).
• In The Wire, Chris and Snoop find out which drug dealers are from New York and trying to muscle in on their territory by asking things only someone from Baltimore would know. Unfortunately, Snoop isn't that knowledgeable of local pop culture herself, and after she almost kills someone who gives a correct answer, Chris decides that he should handle asking the questions.
• In an episode of Xena: Warrior Princess, Xena identifies a supposed Spartan deserter as a Persian spy by asking him if he is eager to see the waterfall in his home town again. Of course, there is no waterfall.
• The X-Files: In "Three of a Kind", this is actually used against the Lone Gunmen when Byers is attempting to pass himself off as a defense contractor. One of the other players at the poker table asks him a question: Langley, who has been providing research and info to support Byers' masquerade, comes up empty (because the question is nonsensical) and tells Byers to fold. Byers, unfortunately, is feeling too bold for his own good, and exposes himself with a blatant lie.

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