Refitted for Sequel

So you've finished writing your new adventure film. It has everything you can imagine, with a very evil villain, a mysterious female-lead and even a biplane chase! The studio loves it and you get it green-lit. But as you move into pre-production, you notice the film needs to get trimmed down. The biplane chase was great, but you know it has to go, as it adds to little to the plot. A shame, it even got storyboarded and most of the models were already built. But with it left out, the pacing is improved and the change was for the better. The film eventually gets released to rave reviews and great box-office numbers. So the studio calls you up for a sequel! You start working on script and realize something:

...I could work the biplane chase into this one!

The sequence remains virtually identical to its first outing, except that this time a different girl is behind our hero. Just because you didn't use it the first time, doesn't mean it never can be used, instead it can be refitted for the sequel.

The reasons for dropping a sequence is usually:
 * Time or pacing
 * Some sequences just end up being too long in the end, or there is one chase too many.
 * Budgetary or time-constraints
 * Everything in a film costs money, A LOT of money. Sometimes some things will just be too expensive and needs to be cut. In other cases, to avoid a delay you need to take something out.
 * Technological
 * Sometimes, the technology needed to produce the sequence (or at least on budget) is not there yet.

Another variation is when doing an adaptation of a work, a scene from an earlier installments makes into a later one. Sometimes it isn’t a sequence that's re-used, but can be things like sets or props made for an earlier installment.

Most of these tend to be removed early, anywhere from the script writing to having gotten some sets built.

This is mostly a film, TV or video-game based trope, as readers have a lot more tolerance for length and writing an extra sequence doesn’t cost anything other than time.

For video-games, it can be related to Dummied Out. With the advent of DLC, this allows makers to finish parts that were not in the main game. The difference of how is received varies greatly as sometimes you are paying more for what originally was going to be included in the original game, while other times it can be expanded into a much larger role (see Fallout: New Vegas example below).

Anime

 * When Mobile Suit Gundam had its episode count cut late in development a lot of material planned for the ending was removed. Many of the concepts would be used in Mobile Suit Zeta Gundam

Film

 * Indiana Jones and the Temple of Doom included several sequences originally planned for Raiders of the Lost Ark:
 * Much of the original sword fight that would have been between Indy and the swordsman he shot instead made it into the sword fight at the end of Temple of Doom (where Indy tries the same thing, but his gun is missing).
 * The minecart chase was originally planned for Raiders (and even storyboarded) but had to be cut for pacing reasons.
 * Indy was originally to find the headpiece to the Staff of Ra in Shanghai, but the scene was cut before shooting, but major parts of it (like him using the rolling disk) is in the opening of "Temple".
 * The opening to The Lost World: Jurassic Park is adapted from the opening of the first Jurassic Park book.
 * Many scenes in Jurassic Park III are from the other two books: The river chase from the first and the aviary and cloning lab from The Lost World.
 * A rare case of a scene being shot for the first and used (not remade) in the sequel: The opening to The Karate Kid, Part II was originally intended as the ending of Part I.
 * The dream sequence from Toy Story 2 and the idea of opening on a Show Within a Show version of Buzz Lightyear were scenes that had originally been planned from the first film.
 * Considering the immensity of the Star Wars universe, a lot of ideas get recycled. A New Hope was to feature a ground battle at the Rebel base on Yavin, many of the ideas were later adapted to the Battle of Endor (a similar forested planetoid) in Return of the Jedi while the battle itself would feature in just about every videogame of an appropriate era. While Jedi turned the Wookiee planet into the Ewok one, Revenge of the Sith actually went to Wookiee homeworld Kashyyyk. The planet which would become Coruscant was first planned for Jedi, but realizing a citywide planet onscreen was technically impossible at the time, so a second Death Star was used instead. Just about everything in the expanded universe and the Disney sequel has used Luke's originally planned family name of "Starkiller" for something.
 * The Lion King originally had a scene where Timon refused to go help Simba and Pumbaa trying to encourage him. The POV Sequel features a similar scene that relates to Timon's overall "dream home" subplot.
 * Also, said POV Sequel takes an unused song from the original, and shows Timon's backstory.
 * The lava whales from Atlantis: Milo's Return.
 * Vito's backstory in The Godfather: Part II is taken from scenes left out of the original novel.
 * The bathroom set in X2: X-Men United was originally built for a flashback scene Cyclops discovering his powers, that was left before being shot.
 * Finn McMissile was originally going to appear in the first Cars film as a character in a movie Lightning McQueen and Sally Carrera were watching in at a drive-in movie theater, but that scene was cut. He did appear in person in the sequel, however.
 * Aladdin only features one version of "Arabian Nights". The others which lyricist Howard Ashman had written ended up on both sequels (with the Return of Jafar one also being the TV series theme).

Literature

 * The opening chapter of Harry Potter and the Half-Blood Prince, in which Cornelius Fudge meets with the Muggle Prime Minister, was originally written for the first book. After cutting it from the first book, J. K. Rowling reworked it as an opening for the third and later fifth book, but ultimately it didn't get used until book six.
 * In a bigger case of this, the entire Half-Blood Prince storyline was originally intended for the second book (in fact, Harry Potter and the Half-Blood Prince was its working title), but Rowling realized "that I had two major plots here that really did not work too well together side-by-side, so one had to be pulled out." She also decided that it was too early in the series to reveal so much information about Snape.

Video Games

 * The DLC to Fallout: New Vegas is based around this. Originally it was going to be another partner named Ulysses, having been part of Caesar's Legion. He was removed from the main game, but was expanded to being hinted in the first DLC and then becoming a major character in Lonesome Road.
 * Fallout: Van Buren was canceled, but the majority of the plot and Caesar's Legion was incorporated into New Vegas.
 * And the parts of Van Buren that weren't part of New Vegas proper were used for DLC, namely Honest Hearts.
 * Originally, Super Mario Galaxy was going to feature more levels, characters, enemies, and power ups (such as the Cloud Flower and the Rock Mushroom, as well as the inclusion of Yoshi), but all of them were dropped from the final version of the game. However this also led to the creation of the game's sequel, Super Mario Galaxy 2, which became of these abandoned concepts, as well as an Early-Bird Cameo of Yoshi in the first game as two different planets encountered there.