When a character pretends to suffer from amnesia, or some other kind of memory loss.
The motivation for doing this varies: someone who has recently acted like a jackass or gone through an embarrassing situation may simply not want to relive it with others. A victim of Mind Control may seek an excuse to not talk about any pain they may have caused friends and family. A more nefarious character may fake memory loss to remove suspicion from themselves for a crime they committed, or to refrain from divulging sensitive information to their enemies.
The amount of memory a character may claim to have lost can range from just a few days, months, or even entire lifetimes. This can often depend on how vital it is to keep quiet about the incidents in question.
Faking amnesia is usually more believable to others when the individual has recently gone through some kind of trauma, like a blow to the head or Demonic Possession. A suspicious character may attempt to trick the faux amnesiac into mentioning something about the events to prove that they remember it after all. If the faker accidentally slips up and gives themselves away, they may make a big show about their "miraculous recovery." A character who really had amnesia at some point may recover but keep it secret and feign to still have amnesia, to take advantage of it (for example, because Amnesiacs Are Innocent).
This can sometimes overlap with Fake Defector, if the character is faking memory loss for the sake of temporarily joining their enemies.
A sub trope of Obfuscating Disability. Compare Memory Gambit, in which a character arranges to actually have their memories removed to further their plans. Not to be confused with Amnesiac Liar, in which an individual who truly has amnesia is fooled into believing a falsehood they told before acquiring the condition.
- In the Alien-esque hentai Alien from the Darkness, the lone survivor of a derelict ship pretends to have amnesia, and is thus unable to tell her rescuers what happened to the rest of her crew-mates. This is all to hide the fact that she is in fact the host to the alien being that killed them all.
- Inverted in A Certain Magical Index. Touma loses his memory but passes it off as a joke so Index doesn't feel bad.
- The water fairy Athena Glory in ARIA does this as a prank to her student, Alice.
- Arisa has the titular character pretend to have developed amnesia after she threw herself out of a window.
- In the second series of Code Geass, Lelouch adds this to part of his masquerade early on in order to throw off suspicion that he has regained his memories.
- In episode 26 of Hayate the Combat Butler, after a fight with some baddies, Hayate ends up with a blow to the head, rendering him unconscious. Ayumu, being there when it happened helped Hayate tend to his wounds. When Hayate woke up, Ayumu then asks whether he likes her or not. Hayate then ends up faking amnesia in order to avoid answering the question. Hilarity Ensues.
- In an episode of Ōkami-san, Ryoko suffers from actual amnesia, where she thinks she's thirteen. When she later gets better, she pretends not to remember the entire day due to being embarrassed. Ringo catches her when she remembers eating.
- In Tekkaman Blade, D-Boy initially appears to have amnesia, but turns out to be faking it. Late in the series, he starts losing his memory for real.
- In Bokura no Kiseki, Harusumi pretends to be unable to remember his past-life identity to keep himself safe from any enemies he might "inherit" from his previous life as Princess Veronica. The bluff is maintained because everyone has gaps in their past-life memories and another classmate, Zeze, also claims he can't (and doesn't want to) remember.
- In the Marvel comic Agent X, The Taskmaster accuses Alex Hayden of being Wade Wilson pulling this trick. This ends up being a subversion, as while it's unclear whether he is Deadpool or not, the amnesia is very real. Then, it turns out Alex Hayden isn't even Wade!
- About half of Norman Osborn's amnesiac relapses are fake.
- The New 52 version of Superboy's cover story in the "small town" simulation.
- In Supergirl story The Supergirl from Krypton Batman suspects that Kara is pulling this trick. However it is subverted: she really suffers from memory loss owing to kryptonite poisoning.
- The Earth-2 Catwoman was revealed to have been suffering from Amnesiac Dissonance the whole time she'd been Catwoman, and when she regained her original memories she forgot about her time as Catwoman. In a later retcon, she admitted to making this up in order to make her reformation easier.
- Calvin and Hobbes: Calvin once tried this as an excuse for his terrible grades. His dad wasn't fooled.
- While You Were Sleeping plays with this: Peter Gallagher's character, upon waking up from a coma, doesn't remember his fiancée (because they really aren't engaged, his family just thinks they are), so his family assumes that he's amnesiac. He figures out there's been some sort of mix-up, but he continues playing along with the amnesia story to avoid upsetting the family too much.
- In French movie The Gendarme to Stroll, Gendarme Fougasse suffered only from a short amnesia after an accident, but he likes so much the convalescent home he's staying in, he pretends in order to remain longer.
- In TRON, Flynn, when befriending Ram and Tron, uses the excuse that he suffered some memory disorientation while being transported to the Game Grid to hide the fact that he's actually a User that got beamed into the computer world by the MCP.
- In Mass Effect: Retribution, when a rescue squad recovers a kidnapped character and asks for his name, he is unable to answer and claims that amnesia is the cause. As it turns out, he has been implanted with alien tech by Cerberus, allowing his body to be remote-controlled by the Reapers. The claim of amnesia was used by the Reapers to avoid the question as they were at that time unable to learn his name by reading his mind. It works horrifyingly well.
- The Title character from the Robin McKinley novel Sunshine pretends she has PTSD that made her forget or block her memories after escaping from being held captive by vampires. She does have PTSD, but she hadn't forgotten anything; she just didn't want to talk about it or explain A) why she saved a vampire and B) how she saved a vampire. That is to say, by using her magic that she hadn't used since childhood to make it so a certain vampire could walk under sunlight, which everyone agrees is impossible.
- In The Legendsong Saga Glynn does this to hide her ignorance about Keltor. She ‘regains’ her memory as she learns more and can create a cover story.
- The eponymous protagonist of Papillon feigns having amnesia after being caught receiving contraband coconuts and cigarettes while in solitary confinement. The warden is frustrated by the inability to get a name and other details from Papillon and orders him to finish the final four months of his sentence without a dinner meal. Despite nearly dying of malnourishment, Papillon remembers to continue the game upon his release and "mistakes" the end of his solitary time as a pardon from the Penal Colony altogether.
- Bobby Pendragon, from The Pendragon Adventure, feigns amnesia to get the Tribunal of Rayne to trust him. He fails to trick them. It's later revealed that they played along for completely different reasons.
- In Jedi Apprentice: The Hidden Past, a dictatorship's favorite punishment is to destroy the memories of anyone who causes trouble. Some of them are left to wander the streets, but the worst troublemakers are shipped to dangerous worlds with floating cameras following them and broadcasting what happens. Thirteen-year-old Obi-Wan Kenobi ends up being put through the procedure. Thanks to The Force he is able to resist and retain his memories, but he pretends to remember nothing in an act of Obfuscating Stupidity.
- Similarly, in Rebel Force someone who learned how to make amnesiac assassins captures Luke Skywalker. Thanks to The Force — and Obi-Wan's spirit — helping, he remembers everything, but fakes it and does a very good job of acting, for days, in order to lull Soresh into thinking it worked so he could turn on him when the time was right.
- In the Dirty Bertie story "Worms!", Bertie pretends to have a very selective form of amnesia to try and get out of going to Angela's party, but it doesn't work.
- Xander pulls this in the Buffy the Vampire Slayer episode "The Pack", after being possessed by the spirit of a hyena. After Buffy and Willow save him, he tells them that he can't remember a thing and hopes he didn't do anything "too embarrassing". Giles, however, sees right through it.
Giles: I've been reading up on my animal possession and I cannot find anything anywhere about memory loss afterward.
Xander: Did you tell them that?
Giles: Your secret dies with me.
Xander: Shoot me, stuff me, mount me.
- In a late-season arc of Wonderfalls, Heidi Gotts gets bumped on the head and decides to fake amnesia because so many people think that's exactly how amnesia works.
Heidi Gotts: I wasn't faking it at first! I really did still think we were married!... for a few seconds...
- Used by Mrs. Slocomb in a later episode of Are You Being Served? when she pretended to have forgotten everything since early childhood and spent the majority of the episode acting like a schoolgirl. The ordeal was a ploy to scare the management with a possible lawsuit.
- In Kousoku Sentai Turboranger, Pink Turbo decides to fake memory loss to join the bad guys after taking a blow to the head in a battle, in a gambit to acquire an antitode for the poisoned Blue Turbo.
- Supernatural: Dean fakes a case of Death Amnesia after being pulled out of hell by Castiel.
- Inverted in an episode of Human Target. A client who has amnesia takes part in a sting to trick the bad guys by pretending not to have amnesia. To do this he has to convince them that he was faking it. It makes sense in context.
- In the Starsky & Hutch episode "Partners," Hutch apparently gets amnesia from a car crash at the beginning of the episode. It's played as a standard amnesia story for the rest of the episode, with Starsky trying to jog his memory through a Clip Show, until Hutch admits in the last five minutes that he was faking because he was so angry at Starsky for crashing the car.
- Señor Chang of Community fakes a condition called "Changnesia" for the better part of a season.
- After Beckett is shot by a sniper, Castle admits his feelings for her. After she wakes up in the hospital, he asks if she remembers anything about the shooting. Beckett claims that she doesn't. At the end of the episode, though, after a psychiatrist asks her what she remembers, she admits that she remembers everything. Castle later finds out and is not amused.
- One episode features the "recovers but keeps it secret" variant with a witness who had been mentally stuck in the 1970's.
- An episode of Private Practice has a depressed woman ask to undergo shock therapy in order to be happy again. It appears to work, except she doesn't remember her fiancé anymore. Violet, an experienced psychiatrist, calls bullshit on that, and the woman eventually admits that she pretended, as she feels happy until he walks in the room. In the end, the doctors support her story and tell the fiancé to leave her be.
- In Grey's Anatomy, a seriously-hurt woman is found at the site of a ferry accident. Her face is beyond recognition, and she has no memory of who she is. Alex dubs her Ava, and Sloan makes her a new face. Eventually, though, Alex figures out that her memory has returned, but she kept on playing the amnesiac, as her former life sucked.
- In Breaking Bad, Walt pretends to not remember anything so he won't have to explain where he's been or what he's done for a period of time. He does admit to his psychiatrist that he's faking it (so that he can be released from the hospital rather than being held for evaluation), but also points out that doctor/patient confidentiality prevents the psychiatrist from telling anyone else.
- In iZombie, Blaine takes the second version of the zombie cure and loses his memory. He becomes a much more pleasant person, and Peyton falls for him again. Ravi's attempt to cure the amnesia fails to work, but Don E suspects that Blaine is lying and tells Ravi. Ravi tells Peyton, who asks Blaine. He admits that he did lose his memories for a few days, but then everything came flooding back. He decided that he liked who he was as an amnesiac far more than his typical persona. Unfortunately for him, Peyton doesn't buy it and leaves, setting Blaine back onto the dark path. Of course, at that point, he can't hide the truth any more, as Major has also taken the cure, which means that everyone will know anyway in a few days.
- In The X-Files, Mulder jokingly pretends to not know who Scully is for a brief moment in the episode "Deadalive".
- In the CSI episode "Fallen Idols", a high school cheerleader goes missing after a Deadly Prank on her cheating boyfriend. When she's found heavily injured later, she pretends not to remember anything, but Grissom quickly calls her out.
Grissom: I wish I could get selective amnesia. There's a lot in my past I'd like to forget about.
- In Final Fantasy XIII, Vanille pretends that she's forgotten a substantial plot-relevant swath of memory in order to avoid having to share her Dark and Troubled Past (and its ramifications for their current situation) with the rest of the party. Her partner Fang, who really has forgotten, eventually tricks her into admitting it by pretending that she's also been faking her own amnesia.
- In Hyperdimension Neptunia Rebirth 1, while pursuing the defeated Black Heart, Neptune runs into Noire (who is really the un-transformed Black Heart). When Neptune realizes Noire is badly hurt, Noire pretends very badly to have amnesia and not to remember what happened to her. IF sees straight through it, but Neptune and Compa both fall for it.
- At the end of Sly 3: Honor Among Thieves Sly pretends to have amnesia in order to get close to Carmelita Fox (and avoid arrest). She tells him that he's her partner.
- In the first Kingdom Hearts, Kairi claims to remember "nothing at all" about her home world. The way the scene is framed is classic Japanese cinematography indicating she's not being truthful. She later owns up about it…while inside of Sora's heart, no less!
- Seemingly subverted but actually played straight by Xehanort. It's assumed that he lost his memory after the fight against Aqua at the end of Birth By Sleep, but Braig in a flashback in Dream Drop Distance thinks he never lost his memory at all. The truth is he did lose his memory, he just recovered it quicker then people think.
- Archer in Fate/stay night claims to not remember which Heroic Spirit he is in order to carry out his plan to kill Shirou while making it seem like he was just another casualty of the Holy Grail War. (A Double Subversion, as he mentions that at first he really didn't know who he was, but he remembered fairly quickly. He just never let on that he had.)
- Played with in Virtue's Last Reward. K can be one of two people, depending on the timeline. Kyle really is amnesiac, but on one particular timeline Akane pretends to be Kyle and in her case amnesia was a lie.
- In Super Robot Wars X, Tobia fakes amnesia to avoid explaining his situation to the others, more specifically the ones who come from Tobia's past in the UC Gundam timeline.
- Played for laughs in Skin Horse: when Animal Control shows up to capture Sweetheart, Unity panics and feigns amnesia. She's apparently done this before.
- In Lost Opportunity Louwrens does this after being transported to an alien (but somewhat familiar) planet and transformed into an anthropomorphic dog.
- In Girl Genius, Lucrezia pulls this whilst possessing Agatha's body, telling Agatha's rescue party that she's been drugged and can't remember any of them. She manages to pull it off for a while, too, since no-one imagines for a second that it could be anyone other than Agatha talking to them. It isn't until she encounters someone that knew the original Lucrezia and recognises her mannerisms that it all goes downhill.
- In Flander's Company season 4, both Hippolyte and Caleb pretend to be amnesiac in the alternate universe. It's Hippolyte's idea, at first because he thinks the true story would be too unbelievable. Afterward, they don't want their status of supervillains to come into light in a society full of superheroes.
- In Hey Arnold!, Helga pretends to have amnesia. She did originally have amnesia, but recovered from it in the morning. Her mother told her that Arnold took care of her that day, which prompted her to fake it so he would continue to take care of her.
- Ambiguous but heavily implied to be the case with Terra in the Series Finale of Teen Titans. When Beast Boy claims she was so happy as a Titan she comments that things were never the way he remembered them, and Slade tells Beast Boy she chooses to not remember.
- During the Nuremberg Trials and the lead-up to it, former Nazi Party deputy Rudolf Hess pretended that he had lost most of his memories, making a show out of not recognizing the other defendants. None of the prosecutors nor any of his former colleagues were buying it.