Flashback Nightmare

A convenient way of framing a Flash Back to fit in the narrative flow.

Some people, when they sleep, get chased by giant hot dogs, fall down bottomless pits (where they presumably die of dehydration), see their best friends wearing crowns, or have other disturbing, sometimes Freudian experiences cooked up specially for them by their subconscious.

Then there are these people. The subconscious barely has to lift a finger. Their exact real-life experiences can provide plenty of finished material, and their dreams are moment-for-moment replays of something that happened to them before.

Some dreamers may have stretches of Flashback Nightmare in other dreams. As, for instance, dreaming of an encounter with a villain, but at the moment they actually meet, the villain is walking about with the wounds the hero gave him at the end of it.

Subtrope of Bad Dreams.

Anime and Manga

 * Used in Code Geass to show how Lelouch was disowned by the royal family and sent to Japan.
 * Slayers: In the first season, Zelgadis has a flashback about when his great-grandfather, the priest Rezo, turned him into a chimera, igniting his Heel Face Turn.
 * In the Guyver OAV, Sho has a nightmare about his fight with Lisker/Guyver 2, and how he subsequently melted/disintegrated.
 * In the Fullmetal Alchemist anime, during the Central Library fight between Scar and the homunculi, the camera pans out and shows the glass of the windows shattering as they first start to charge at each other. Later, the fight is shown as part of a nightmare Scar is having, and he wakes up in the Ishbalan refugee camp.
 * Happens to the resident angst factory Ken at least twice in Digimon Adventure 02: Once in a flashback to his being infected with the Dark Spore during a Tamer's cameo dream, the other during a Whole-Episode Flashback that basically explained his entire rather tear jerking backstory in one go.
 * Used in both versions of Chrono Crusade. In the manga, Chrono has two nightmares that hint at his past without fully revealing it—first, a very symbolic dream that mixes a typical nightmare with bits of truth into it, and then a brief flash of a battle that later gets shown in a proper flashback. In the anime, Rosette has a dream about Joshua that starts off normal before turning into a nightmare that symbolically shows how he was kidnapped by the Big Bad. This introduced Joshua before the flashback episode that explained Rosette's backstory.
 * Evangeline of Mahou Sensei Negima conveniently remembers her defeat at the hands of Nagi when Negi spies on her dream. Of course, later revelations about Evangeline's real power level imply that the real battle probably wasn't quite as one-sided as the one in the dream.
 * Ciel from Black Butler has a nightmare of him on a table and a shadowed figure with glowing eyes hovering over him. He jerks awake and pulls out a gun from under his pillow and points it at Sebastian who was trying to wake him up. One other instance, although Ciel wasn't asleep, is where he recalls some of his horrific past events
 * Agito of Magical Girl Lyrical Nanoha receives these in StrikerS a few episodes after she was introduced, showing her life as a lab subject in an illegal research facility before she was rescued by Zest and Lutecia.
 * Einhart Stratos also receives these in ViVid, though in her case, it's drawn from the memories of the long dead Ancient Belka King whose blood had awakened in her.
 * from Sora no Woto gets this as part of her package deal as a Shell-Shocked Veteran. She's become a convincing Stepford Smiler to hide it, but doesn't always work.
 * In the Tales of Symphonia OAV, Zelos has one of these about.
 * Heartcatch Precure plays with this. There's a dream showing Cure Moonlight fighting and losing to Cure Dark. For Tsubomi, Erika and Itsuki, it's a Call to Adventure. For, it's this. And boy does suffer from it.
 * In the Saint Beast OVAs, both Goh and Shin have dreams of the war in heaven. These are used as a framing device at the beginning and end of the two episodes. Zeus has a flashback daydream in the middle first OVA as well.

Fan Fiction

 * The Portal2 fanfiction Blue Sky has plenty of these, mostly from Wheatley
 * Early on GlaDOS forces Wheatley to relive his worst memory (Taking over the Facility, betraying Chell, and pretty much going insane with the need to Test) over and over again via invasive connections into his mind.
 * In the Dragon Ball Z fanfic Goku's Wish: The Return of Broly, Broly, while knocked out from exhaustion from being revived, sparring with Goku (whom, thanks to his specifying in his wish towards reviving Broly that Broly won't have any of his negative emotions, Broly no longer hates Goku), and then having to fight Vegeta after the latter grew enraged at Goku's decision to revive him after he was sore about his previous wound to his pride from their last encounter, ends up having a nightmare that initially seemed to be flashbacks to his past where he basically was destroying various galaxies, although it then turned more into a premonition nightmare where apparently a duplicate of Broly mocks the current Broly for his growing "soft" from his revival and proceeds to destroy the Earth before Broly wakes up in shock, and it is implied shortly thereafter that Broly was disturbed at the possibility of a duplicate, or worse, that he still has some evil in his heart that somehow avoided purification before revival. Vegeta, while knocked out, also ended up having a flashback to when he fought Broly on New Planet Vegeta, which was enough to actually reopen his wounds.
 * Happy Families Are All Alike, a Naruto / Mahou Sensei Negima crossover, begins with a flashback to a meeting with the Third Hokage.

Comics

 * In Hack Slash, Cassie has a recurring Flashback Nightmare of destroying her undead mother, which she uses to defeat Ashley at their first meeting when he tries to pull a Your Worst Nightmare on her.

Film

 * The Blind Side: Michael occasionally has the awake version of these, when thinking about his Dark and Troubled Past.
 * The opening of Batman Begins.
 * The opening of the Mortal Kombat movie.
 * At the beginning of the film version of The Two Towers, Frodo has a dream that reminds us what happened to Gandalf, although in this case it continues into a sequence which he couldn't possibly have seen.
 * The villain actually has one in Maniac Cop, dreaming about his mutilation in Sing Sing by inmates he put there.
 * In The Terminator, Kyle Reese frequently had nightmares relating to the war against Skynet as well as his hiding from the various H Ks and Terminators.

Literature

 * One of the favorite tropes of Animorphs. Hardly a surprise, considering what they had been through.
 * Harry Potter mostly had semi-prophetic and psychological dreams, but Order of the Phoenix mentioned that his experience in the graveyard in the previous book had supplied a few of these.
 * Scott from The Power of Five had several of these, after a nice spell of Mind Rape and Cold-Blooded Torture.
 * In Dark Life, Ty has one of these about
 * Eve has these constantly in the In Death series.
 * In the novel Ordinary People, Conrad Jarrett has some of his flashbacks to the sailing accident that killed his older brother, during which we gradually learn more about it, while asleep.

Live Action TV

 * Lost: some of the show's characteristic flashbacks are presented as nightmares. One example is Sawyer's flashback in "Outlaws" to his father killing his mother, then himself.
 * The 2010 season of Home and Away started out with Hugo kidnapping Charlie, meaning these formed a part of her arc for the first few weeks.
 * Maddigan's Quest used this to illustrate Timon and Eden's backstory, in particular their parents' execution and the boys' subsequent escape from the future Solis.
 * In the first part of the Monk two parter Mr. Monk Is On the Run, Monk experiences a nightmare of the day Trudy was killed via car bomb, and he couldn't stop it. It was also implied in the same two parter that these nightmares were frequent.
 * In The X-Files, Mulder often has flashback nightmares of his sister's abduction. It may explain his insomnia.

Radio

 * Parodied in Nebulous, where Nebulous often has horrific flashbacks to his childhood - working in the circus.

Tabletop Games

 * The Changelings of Changeling: The Lost suffer from flashbacks to their durance in Arcadia in their dreams. One downside to gaining Wyrd is that these dreams become clearer and more powerful, until eventually they can recall Arcadia with absolute clarity - and their own Clarity suffers as a result, driving them closer to losing their grip on reality entirely.

Video Games

 * Ashley of Trace Memory has the events of her third birthday come in a dream near the start of both games. Then again,
 * Shadow had some in Final Fantasy VI, revealing that . Since the nightmares appear at a very low chance when staying in inns, and even then only if you knew to save his life at the Floating Continent, many players don't even know of their existence.
 * Terra had something similar in the same game: Shortly after she attempts to escape from Narshe (while amnesiac), and ends up falling down the Narshe Caves, she passes out and then a flashback occurs where it is revealed that she was unwillingly subjected to being outfitted with a Slave Crown by Kefka Palazzo, leaving her brainwashed, and then killing over fifty imperial soldiers completely against her will with Kefka cheering her to continue burning them to a crisp, and then witnessing Emperor Gestahl's war speech, a flashback that would certainly have been very horrifying.
 * The regular story chapters of the Visual Novel Planetarian are interspersed with "The Junker's Dream" chapters, which describe the main character's flashback nightmares of his past as a child soldier.
 * Happens in the Visual Novel Songs of Araiah, where Jason has dreams in which
 * In Metal Gear Solid 4: Guns of the Patriots, when Old Snake finds out he has to return to Shadow Moses Island, the setting of the first Metal Gear Solid, he has a playable nightmare flashback complete with PS 1 graphics.
 * It is implied in Metal Gear 2 Solid Snake that Solid Snake frequently experienced nightmares relating to his mission in Outer Heaven.
 * Marshall Anderson of Outlaws (1997 video game) has a recurring nightmare of the man who shot his father, and left him for dead. The nightmare repeats a few times before we finally see the entire scene, and the villain's face is revealed. It isn't until the final confrontation between Anderson and Bob Graham, that we see a Match Cut of Graham and the assailant that we find out that the two characters are one and the same. Que mandatory one-liner.
 * Zero has one of these at the start of Mega Man X 4, and it is also implied that this wasn't the first time he had the nightmare.
 * Super Robot Wars Z 2: Hakai-Hen had Chirico Cuvie experiencing one during the prologue of Scenario 39. It was about the final battle he had with the Barcoff Squadron and it showed how he was sad at the loss of their lives.
 * In Tales of Symphonia: Dawn of the New World, Emil dreams of.
 * In Super Robot Wars MX, Hugo has a nightmare/flashback of the final moments he had with the Cry Wolves. After failing to neutralize the Devil Gundam, the Cry Wolves are taken out one by one. Alberto's son Foglia is turned into a zombie by the Devil Gundam and Hugo tries to reason with Foglia but ultimately gets his Gespenst blown up.

Web Comics

 * Vashiel gets a couple of these in Misfile.
 * Leading to some fans to label him a mass murderer.
 * Vaarsuvius from Order of the Stick gets flashback nightmares of a certain traumatic experience he/she suffered months earlier. To make it worse, trancing, the equivalent of sleep for elves, actually consists of reviewing memories in minute detail for the sake of self-reflection and committing those events to very long-term memory. This makes V's Flashback Nightmares far more literal than any regular example and handily explains V's reluctance to trance.
 * Sarine Elle, central figure in Errant Story, has a real honker of a flashback nightmare about the disastrous birth of her stillborn daughter, which goes far toward explaining her relationship with Meji Hinadori.
 * Jade's second dream in Homestuck after  ends up being this, though to be fair, Jade was going off the rails and Feferi probably didn't mean to startle her. She's just kind of weird like that.
 * Susan of El Goonish Shive has one of finding out about her father's affair.

Web Original

 * Used to establish the backstory in Sailor Nothing.

Web Animation

 * In the beginning of the fifth episode of Super Mario Bros Z, Sonic is experiencing a nightmare harkening back to the day when Mecha Sonic mercilessly slaughtered his friends, and pretty much every single inhabitant of Planet Mobius while torching a large portion of the planet, while Sonic was knocked out from his fight with the Koopa Bros.
 * Played with in Broken Saints, for each of the heroes' Dark and Troubled Pasts.

Western Animation

 * In Exo Squad, Lt. Marsh dreams about Alice Noretti's death, the newest member of his squad who was killed on her very first mission, and it is implied that he has such nightmares quite often but hides it from everyone.

Real Life

 * This can and does happen to people with Post-Traumatic Stress Disorder, including but not limited to combat veterans. While not always in dreams, reliving the traumatic experience in high detail is literally known as a "flashback".
 * People who have experimented heavily in psychotropic drugs also have flashbacks to previous trips.