If you want the page about the game Flashback: Quest for Identity, go here.
A narrative technique in which we're shown events that took place before the episode's main action. Said events may have taken place on-screen earlier, but may also be new scenes depicting things hitherto only referenced.
Can be subverted with a flashback to something that didn't actually happen.
Often provides the added bonus of getting actors into period costumes.
Specific types of flashbacks include:
How We Got Here: The episode opens In Medias Res, then the events leading up to the episode's beginning are explained via flashback.
Mid-Battle Flashback: The character is losing in a fight and flashes back to their training to retrieve the knowledge to win.
Pensieve Flashback: The present-day version of the character shows up inside their own memories of the past, in order to provide snarky commentary or to inexplicably interact with the past.
Rashomon-Style: Multiple flashbacks depicting one event from several different perspectives.
Self-Serving Memory: A character flashes back to an event, only for the flashback to be quite different from what actually happened, usually to make that character look better.
Flashback Within A Flashback: A flashback within a flashback occurs when a character recounts an event in which he/she also flashbacks into ANOTHER event within the first flashback.
Dreaming of Times Gone By and Bad Dreams are two ways to show them. See also Flashback Effects for ways of distinguishing a Flash Back from normal action, and Viewers Are Goldfish for flashbacks to events that are still fresh in the audience's mind. It's also a brilliant way to indulge in some Exposition Of Immortality.
When a character is having a flashback, it can be because of psychic/magical powers, Post Traumatic Stress Disorder or simply resurfacing memories. In either case, it's a common justification for a movie to show the audience a Flashback.
Flashbacks were abused in early issues of the Marvel Transformers Generation 1 comic, with a page or more of some issues used to recreate scenes from previous issues an an apparent attempt to fill space.
In the Total Drama story, Legacy, chapter 2 and most of chapter 3 cover events from years before the main setting, but are told as if they were set in the same time frame.
Chapter 18 of Super Paper Mario X starts with Sonic, as always, scared of going in the water (since he can't swim and will drown in the water, after all). When he is informed that this was not the first time the group had to go through water, Sonic says to "name the times", followed by a flashback to the first Paper Mario X (lampshaded by Mario). When Sonic says there was no way it happened twice, a flashback to Paper Mario X 2 follows.
Chapter 61 of the original includes a flashback to the moment when Sonic, Link and Kirby first met Samus. It also shows the origin of Sonic and Samus's Embarrassing Nicknames.
In The Dark Tower, Book One: The Gunslinger, the first quarter of the novel is devoted to flashbacks to events just prior to the beginning of the novel, and flashbacks to Roland's childhood within those. In Book Four: Wizard and Glass, the bulk of the story is a flashback to a formative event in Roland's early adulthood.
The Phantom of the Opera is told in one giant flashback, as the show's opening scene is of the aged Raoul attending an auction selling off items from the opera house.
Video Games
In a game that revolves around memories, Another Code covers a variety of these.
In Minori's route in Brass Restoration, flashbacks are used much more frequently than needed, often to recap something that happened half a scene ago. Thankfully not as prevalent in other routes.
In Valkyrie Profile, flashbacks are often used to show the events leading up to the Einherjar's deaths.
Halo 3: ODST makes extensive use of this, though technically, it's actually Rookie going through camera recordings, not flashbacks per se, but it still counts.
In Call of Duty 4: Modern Warfare, when Price finds out Zakhaev is behind the game's plot, he decides to roll a flashback to explain the guy's background. Players know this as the "All ghillied up" mission.
Visual Novels
Maji De Watashi Ni Koi Shinasai has flashbacks interspersed between routes as necessary; no single path gives a complete background on the family, with each person's pertinent set of flashbacks happening in their own storyline.
Web Comics
Concerned has an mini-arc when Frohman flashes back to his days at Black Mesa, providing arguably the best Lampshade Hanging of this trope ever as the quote for this page.
In Unforgettable, the female lead is in the habit of replaying events that she witnessed earlier in the episode, often finding a clue from something she saw that didn't seem important at the time.
ThisWapsi Square strip uses a single panel flashback to show what happened last time Fermented Banana played at a wedding.
The entire third story arc of The Senkari is basically an extended flashback where Natalie learns some of the titular characters history..
Web Original
In The Gamers Alliance, various characters have flashbacks which often explain their past and their relationship with other characters.
Unusually for the series, lonelygirl15 episode "Comfort Food" included flashbacks to Daniel's grandmother's funeral. Flashbacks were again used in the series 3 episode "I Miss Her".
Frequently used in The Gungan Council in order to explain why a character has or does something. "It's Not That I Keep Hanging On, I'm Never Letting Go" uses it in spades.
Parodied in episode X of Transolar Galactica, when Captain Trigger gets a flashback without the series actually cutting to it.
Reggie: Oh great, he's having one of his little flashback things.
...
Samson (after half a minute of Trigger staring vacantly into space): ... how long does it take?
Funny Business has a flashback right in the middle of the story that manages to double its overall length, and making what would otherwise be an ordinary Plot Twist into a Shocking Swerve.
Western Animation
Invader Zim also lampshades a common problem with this trope: In "The Fry Cook What Came From All That Space", Zim recalls a flashback of being demoted to fry cook under fry lord Sizz-Lorr, and then escaping. After Zim escapes, it shows Sizz-Lorr alone, shouting at the top of his lungs:
Sizz-Lorr: I will find you Zim, so help me, I will search the entire universe, and I! WILL! FIND YOOOOOOOOU!
(Cut back to present time with Zim and Sizz-Lorr)
Sizz-Lorr: How did you remember what I said if you weren't there?
Used a lot in Phineas and Ferb by the character Dr. Doofenshmirtz, since almost all of his inventions have a backstory and he uses flashbacks to let Perry and the audience know the purpose for it. However, there have been some occasions where he'll skip over a flashback since Perry already knows the story, and on one occasion he had a horrible headache and said it hurt too much to do a flashback.
In "The Belly of the Beast", Perry was going into a flashback of how he escaped, which Doofensmirtz took advantage of by attacking him.
Parodied in "Doof Dynasty", an Elseworlds episode set in ancient China, where this discussion occurs about "Master Perry".
Phineas:...does he know we can't see it? Should we give him some privacy? I don't know the protocol for flash-backs.
Used frequently in Avatar The Last Airbender, usually in the form of someone in the present narrating something that happened in the past (like the flashbacks in "The Storm," "The Avatar and the Firelord," and "The Southern Raiders"). "Zuko Alone" and "Appa's Lost Days" have characters who don't or can't talk about their pasts quietly remembering them in the form of flashbacks.
Danger Mouse: "The Return Of Count Duckula" uses footage of DM's first encounter with Duckula from "The Four Tasks Of Danger Mouse" as a flashback as he recounts the meeting to Colonel K.
