A false ending has two contexts: in literature, film and video games it is a narrative device where the plot seems to be heading to its conclusion, but in reality, there's still more to the story; in a musical composition, however, it is a complete stop of the work or song for one or more seconds before continuing.
The presence of a false ending can be anticipated through a number of ways: the medium itself might betray that it isn't the true ending (i.e. it's only halfway into a book or a song, a film's listed running time hasn't fully elapsed, only half the world has been explored in a video game, etc.), making only stories with indeterminate running length or a multi-story structure able to pull this off effectively; another indicator is the feeling that too much of the story is incomplete when the false ending comes, making it feel like there has to be more.
In L.A. Confidential , it seems like the criminal case that the movie revolves around is completely closed with no loose ends until one of the witnesses admits that she lied about important details to give more importance towards the trial of the people who raped her, exposing a cover-up conspiracy. In The Lord of the Rings: The Return of the King, the director keeps using editing techniques that are indicative of endings in scenes that could be used as such, but continues until the movie finally ends. Spider-Man 3 has two false endings. Another example is in The Simpsons Movie, where, at a very climatic stage in the film, the screen fades away and says "To be continued", which is then followed by the word "Immediately." Also in The Lego Movie 2: The Second Part, at what appears to be a cliffhanger ending, a "The End" sign appears, only for a character to break the fourth wall by insisting that the film will have a happy ending; the same sign appears again at the film's actual ending.
Some movies come to a formal ending, followed by the rolling of the credits, which is almost universally used to indicate that the film has ended, only to have the actors reappear in one or more mid-credits scenes. In comedy films, these sequences may be bloopers or outtakes. In other types of films, the mid-credit scenes may continue the narrative set out in the movie. The Marvel Cinematic Universe movies have become notorious for this, in some cases featuring a mid-credits scene and an end-credits scene in the same movie.
Some examples in video games include Final Fantasy VI and Wild ARMs. Both involve confrontations with the major antagonists at what seems like their final lairs, but instead a crisis occurs and the story continues. A third is in Naval Ops: Warship Gunner, upon sinking the Druna Skass a second time (Which can only happen if the player plays though the game again, as the game resets itself to the beginning if you sink it once), the player is greeted by another supership, that looks just like the Druna Skass. Yet another example is the survival horror game Obscure II, in which the player must wait until the credits roll to their conclusion before gameplay resumes.
Role-playing video games are notorious for having such plot devices. It usually involves the game's main antagonist being defeated, only for a previously mentioned character to be revealed as the "real" villain. One example is The Legend of Zelda: Twilight Princess, in which the main character is apparently about to have a boss fight with the former villain Zant, but Zant reveals he has been working for another Villain. Another example is "Kid Icarus: Uprising" where after you defeat Medusa, credits roll but are quickly interrupted by Hades, the villain for the rest of the game.
In video games, it is difficult to use the false ending device effectively. Nevertheless, in the hands of a skilled designer, there are several methods that allow it to be done. In several video games, such as those with multiple playable characters and story lines, the game may appear to end after defeating a difficult boss, or clearing what appears to be the "Final" level, complete with credits, an outro, and a return to the start screen. These endings are different from bad endings, as everything may appear to be resolved. However, fulfilling conditions such as clearing all the storylines, reloading the save file, or reaching the "ending" in a New Game+ mode may give the player the option to continue on to the real ending.
An example of this is Sonic Adventure, and its sequel Sonic Adventure 2. In the former, while there are six stories to play, only the main character's, Sonic's is the most complete. The other characters' stories are simply side-stories. However, if "all" of the stories are completed, a final story appears that wraps up the game and acts as the "true" ending. In the latter, there are two stories to play, one for the heroes, and one for the villains. Of note is the plot device is hidden in a false Chaos Emerald being used that would destroy the space colony in which the villain Doctor Eggman is using as a base. It is at first implied that Eggman took the false Emerald, but in reality, when the last story is played, again, after the two normal stories are completed, a true conclusion is offered.
Another example could be the survival horror game Resident Evil 2, where, depending on your choice, you get to play with one of the two characters and get a certain ending for one of them to later discover, when you finish playing the second path with the second character, you fight the real final boss and the "true" ending (That may vary depending of which character you have chosen first) is shown. The main difference between both of the "true" endings are that places and times are exchanged, as well as the final dialogue from the game.
The Consequence, the second Kidman DLC for 2014's The Evil Within, features a secret false ending in a similar manner to those shown in the Resident Evil franchise. At one point, Juli Kidman encounters the brain of the game's main antagonist, Ruben Victoriano, sealed inside a glass container hooked up to the STEM system in Beacon Hospital. Should the player choose to shoot the container and break it, the game cuts to black, then begins the credits sequence, cutting short on a postcard depicting Juli, Joseph and Sebastian on a postcard, before promptly returning to the game as Kidman exclaims "What the fuck?!", indicating the whole sequence was a hallucination.
False endings are a known device in classical music. Josef Haydn was fond of them, for example inducing applause at the wrong place in the finales of his String Quartet, Op. 33 No. 2 (nicknamed "The Joke") and Symphony No. 90. The first movement of Prokoviev's Classical Symphony contains false endings.