When creating a movie from a story already well-known in another medium, those making it are often faced with a crippling dilemma. How true can we stay to the source material without risking a failure at the box office? It can be a very hard call for a director. On the one hand, FanDumb will cry "DarthWiki/RuinedFOREVER" should he change one iota of the source material, and he may find himself a victim of [[NeverLiveItDown the fandom's ire from then on]]. On the other hand, ''not'' changing a thing can result in either a very poorly-made movie or one that relies so heavily on the source material that people unfamiliar with the work will be completely lost.

The scale runs something like this:
* 5. Identical Adaptation: A movie in which next to nothing is changed. These rarely fare well outside the established {{Fandom}}.
* 4. Near-Identical Adaptation: A movie that changes the material just enough to gain a specific rating or be of reasonable length. Usually rereleased with a DirectorsCut.
* 3. PragmaticAdaptation: Probably the ideal rating. A movie that manages to capture the spirit of the original work, while at the same time, embracing the new medium. These are generally big hits.
* 2. Recognizable Adaptation: Still bears enough resemblance to its source material that it can be realized as an adaptation. May involve a SettingUpdate.
* 1. InNameOnly: Shares only the name and possibly the main characters. It likely could have stood on its own as an original work otherwise.

The scale, however, is not set in stone, and often times, there is overlap. Also, TropesAreNotBad as any movie in any of these categories can become a great success. However, the further a movie falls from the center, the less likely that is.

This trope is usually applied to movie adaptations -- TheFilmOfTheBook especially -- although it can be applied to adaptations ''from'' movies as well, since other formats (books, comics, television series) have room for more material. See also TheProblemWithLicensedGames for the video game equivalent.

!Examples:

!! Type 5:
* ''BlackButler'' season 3 and "Book of Murder" {{OVA}}
* ''Manga/BlackLagoon'' anime
* ''Manga/MahouSenseiNegima'' {{OVA}}
* ''ComicBook/TheMaxx'' animated series
* ''Film/RosemarysBaby''
* ''Film/RosencrantzAndGuildensternAreDead''
* ''ComicBook/SinCity''
* Many film adaptations of stage musicals; excellent examples include:
** ''Theatre/MyFairLady''
** ''ThePhantomOfTheOpera''
** ''Film/TheProducers'' (2005 version)

!! Type 4:
* ''{{Literature/Holes}}''
* ''Film/ThePrincessBride''
* ''WesternAnimation/TheLordOfTheRings'' (Creator/RalphBakshi's adaptation)
* ''Film/HarryPotterAndThePhilosophersStone'' and ''[[Film/HarryPotterAndTheChamberOfSecrets the Chamber of Secrets]]''
* ''{{Film/Watchmen}}''
* ''Film/BrokebackMountain''
* ''Film/{{Kick Ass}} ''
* ''Theatre/FiddlerOnTheRoof'' cuts a few musical numbers, but is otherwise identical
* ''Film/FightClub''
* ''[[Manga/FullmetalAlchemist Fullmetal Alchemist: Brotherhood]]''
* ''Film/TheGodfather''
* The animated version of ''WesternAnimation/TheHobbit''
* ''Film/ScottPilgrim''
* ''Literature/TheLittlePrince'' (1974 film musical)
* ''Theatre/TheBlueBird'' (1976 film)
* ''Literature/ToKillAMockingbird''
* ''Discworld/{{Hogfather}}''
* ''Film/NationalLampoonsVacation'' changes some names and gives the story a mostly-happy ending
* ''Literature/LifeOfPi''
* ''Film/TheHungerGames'', ''[[Film/TheHungerGamesCatchingFire Catching Fire]]'', and both parts of ''[[Film/TheHungerGamesMockingjay Mockingjay]]''
* ''Film/EndersGame''
* ''Film/TheSilenceOfTheLambs''
* ''Film/VampireAcademy'' is mostly loyal to the first novel of the ''Literature/VampireAcademy'' series. The differences are generally minor. Three characters receive name changes, one character is younger and more attractive than her book counterpart, three characters are of different age than their book counterparts, two characters who survive the original novel are killed in the film, [[spoiler:Natalie Dashkov kills a different person than the one she killed in the novel (Ray instead of Mr. Nagy)]], Lissa does not practice SelfHarm, and some minor book characters do not appear at all in the films. The most obvious change comes from the style of clothes the characters wear. In the books, the students of the Academy wear regular street clothes. It is a sore spot for Rose that she can't afford decent clothing, at one point wearing clothes she received from the Salvation Army. In the films, both Moroi and dhampir students wear school uniforms. Rose wears a relatively stylish uniform.
* ''Film/{{The Maze Runner|2014}}''
* ''Film/TheMartian''

!! Type 3: PragmaticAdaptation
* Manga/{{Akira}}
* Studio Ghibli's Anime/{{Arrietty}}, to the [[Literature/TheBorrowers original novel by Mary Norton]], making it the most faithful film or TV adaptation of the original books to date.
* {{Marvel}}'s many movie franchises.
* ''Anime/DeathNote''
* ''Film/TheGodfatherPartII''
* ''Film/HarryPotterAndThePrisonerOfAzkaban'', ''[[Film/HarryPotterAndTheGobletOfFire Goblet of Fire]]'', ''[[Film/HarryPotterAndTheOrderOfThePhoenix Order of the Phoenix]]'', and ''[[Film/HarryPotterAndTheHalfBloodPrince Half-Blood Prince]]''. Both parts of ''[[Film/HarryPotterAndTheDeathlyHallows Deathly Hallows]]'' are about a 3.5, as they cover the novel more thoroughly and faithfully than the previous four films, but not as much as the [[Film/HarryPotterAndThePhilosophersStone first]] [[Film/HarryPotterAndTheChamberOfSecrets two]].
* ''Film/TheLordOfTheRings'' (Peter Jackson's adaptations)
* Subverted with ''[[Film/TwoThousandOneASpaceOdyssey 2001]]'', as both the book [[TheFilmOfTheBook and its film version]] were written in tandem by their respective authors.
* ''WesternAnimation/TheLastUnicorn'', adapted by the original author.
* The {{Novelization}} of ''RevengeOfTheSith''
* ''Series/TheWalkingDead''
* ''Manga/TheWorldGodOnlyKnows'' anime
* The first ''[[Film/TheNeverendingStory Neverending Story]]'' film
* The first ''Franchise/JurassicPark'' movie
* ''Anime/MacrossDoYouRememberLove'', for the original ''Anime/SuperDimensionFortressMacross''.
* ''Film/SweeneyToddTheDemonBarberOfFleetStreet''
* ''Film/BeingThere''
* ''Literature/CharlieAndTheChocolateFactory'' and the [[Film/WillyWonkaAndTheChocolateFactory 1971 film]] and [[Theatre/CharlieAndTheChocolateFactory 2013 stage musical]].
* ''Annie'' (both the [[{{Film/Annie1982}} 1982]] and [[{{Film/Annie1999}} 1999]] versions)
* ''Film/SpaceBattleshipYamato'', due to character changes
* ''SonicX'' (Though the SonicAdventureSeries based arcs could go up to a 4)
* ''Film/TheColourOfMagic''
* ''Discworld/GoingPostal'' is debatable somewhere between 3 and 2.
* ''Literature/TheChroniclesOfNarnia'' is somewhere between 3 and 4. The first film is probably a 4 while the other two films are closer to 3.
* ''{{WesternAnimation/Coraline}}'', with Neil Gaiman's support.
* ''Film/HangmansCurse'': the story is the same but the background is dramatically different.
* ''OuranHighSchoolHostClub''
* ''Anime/BlackButler'' season 1 (arguably a 2.5 for the anime-original ending, but it's still very close in tone and theme to the manga, and the previous 3/4 of the anime are very faithful to the manga)
* Season 1-4 of ''Series/GameOfThrones''
* The first two episodes of ''Manga/YamadaKunAndTheSevenWitches''
* ''Film/{{Goldfinger}}'', one of the very few adaptations considered ''better'' than the original book

!! Type 2:
* ''Film/{{Seventh Son|2015}}'', the movie adaptation of ''Literature/TheWardstoneChronicles''
* ''VideoGame/EightyDays'' is about a 1.5: same characters, includes much of the plot and various supporting characters in certain routes, but in a [[{{Steampunk}} substantially changed world]], and most of the other routes are completely original.
* ''WesternAnimation/HowToTrainYourDragon''
* ''Film/DragonballEvolution''
* ''Series/DresdenFiles'' TV Series
* ''Series/{{Elementary}}'' TV Series
* ''Anime/HowlsMovingCastle''
* ''Series/{{Battlestar Galactica|2003}}'' remake
* ''Cirque Du Freak'' based on the ''Literature/SagaOfDarrenShan'' books
* ''Series/LegendOfTheSeeker'', based of the ''Literature/SwordOfTruth'' series.
* Creator/StanleyKubrick's film of ''Film/TheShining'' is interesting in that it starts out as a Type 4, but it gradually deviates further and further from the book until it becomes a Type 2.
* Disney/{{Pinocchio}} deleted many of the characters and challenges of [[Literature/TheAdventuresOfPinocchio the original book]].
* ''Anime/FullmetalAlchemist'' (2003 adaptation)
* Abridged version of ''[[http://www.youtube.com/watch?v=ofKsgMCyIXc Pinocchio]]'' by Phoenix Games
* ''Film/TheLastAirbender''
* ''WesternAnimation/LegendOfTheGuardiansTheOwlsOfGaHoole'' directed by Zack Snyder
* ''{{WesternAnimation/Wayside}}''
* ''Film/{{Eragon}}''
* ''Film/TheNeverendingStory 2: The Next Chapter''
* ''Film/{{Thunderbirds}}'', dramatic change in premise and mood.
* ''Manga/{{Trigun}}'' (anime), though it occasionally goes up to three.
* First reports from translators claim that the 2011 LiveActionAdaptation of ''Anime/RanmaOneHalf'' starts here and may dip lower.
* ''Film/TheManWhoFellToEarth''
* ''Anime/TenchiUniverse''
* ''Film/ThePowerOfOne'' movie
* ''VideoGame/{{Bionicle}}'' [[TheProblemWithLicensedGames the game]] and ''Bionicle Heroes''.
* ''Anime/SonicTheHedgehogTheMovie''
* ''WesternAnimation/TheKingAndI''
* ''Film/TheWizardOfOz'' (1939). ''Almost'' a 3, but not quite.
* ''WesternAnimation/TheSecretOfNIMH''
* Disney's ''Disney/TheLittleMermaid'', ''Disney/BeautyAndTheBeast'', and''Disney/{{Aladdin}}''.
* The animated version of ''WesternAnimation/TheReturnOfTheKing''
* ''Fanfic/TheCalvinverse''
* ''[[Film/PercyJacksonAndTheOlympians The Lightning Thief]]''
* ''Series/{{Sherlock}}''
* ''Series/{{Hannibal}}''
* All but the first two episodes of the live-action drama of ''Manga/YamadaKunAndTheSevenWitches''
* ''Film/TheCatInTheHat''
* ''The Adventures of Super Mario Bros. 3'' and ''Super Mario World''
* ''[[Film/HoratioHornblower Captain Horatio Hornblower, R. N.]]''
* ''Series/HoratioHornblower''
* ''Series/MastersOfSex'', based on RealLife
* ''Theatre/LesMiserables'' the musical
* ''Film/MazeRunnerTheScorchTrials''
* ''Sands of Destruction'' was made into a [[VideoGame/SandsOfDestruction game]], [[Anime/SandsOfDestruction anime]], and [[Manga/SandsOfDestruction manga]] with very different plots.
* ''Film/GuardiansOfTheGalaxy''
* ''Series/{{The 100}}''
* Season 5 forward of ''Series/GameOfThrones''.
* ''Film/TheDivergentSeriesAllegiant''.
* ''Film/TheNameOfTheRose''
* ''Film/DrWhoAndTheDaleks'' and ''Film/DaleksInvasionEarth2150AD'', the AlternateContinuity remakes of the first two Dalek serials from ''Series/DoctorWho''.
* ''Film/CharlieAndTheChocolateFactory'' has a massively changed Willy Wonka.

!! Type 1:
* Much of the Franchise/DisneyAnimatedCanon (''Disney/TheHunchbackOfNotreDame'' and ''Disney/TheJungleBook'' especially)
* ''Film/AlteredStates''
* ''Film/CheaperByTheDozen''
* Studio Ghibli's ''Anime/TalesFromEarthsea''
* ''Film/{{Catwoman}}''
* ''WesternAnimation/{{Shrek}}''
* ''Film/TheRunningMan''
* ''Film/EllaEnchanted''
* ''Film/TheLeagueOfExtraordinaryGentlemen''
* ''Film/{{Jumper}}''
* ''Film/PeterBenchleysCreature''
* ''Film/StuartLittle''
* ''Film/TheNeverendingStory 3: Escape From Fantasia''
* ''Film/TheLostWorldJurassicPark''
* ''Film/TheNutcrackerIn3D'', to both the book and ballet
* The ''Film/SuperMarioBros'' movie and ''Series/TheSuperMarioBrosSuperShow''
* ''Film/StarshipTroopers''
* ''Anime/BubblegumCrisis Tokyo 2040''
* ''WesternAnimation/AdventuresOfSonicTheHedgehog'', ''WesternAnimation/SonicSatAM'', and ''WesternAnimation/SonicUnderground''
* The Franchise/{{Universal|Horror}} and Film/HammerHorror takes on ''Film/{{Dracula}}'' and ''Film/{{Frankenstein}}'' (shading a bit into Type 2 for the Universal version of ''Dracula'').
* Most of the ''Film/ResidentEvil'' films, though the rejected George A. Romero script treatment would have been a 3
* ''Film/TheLawnmowerMan'', so much that Creator/StephenKing took legal action to remove his association with the film
* ''Film/{{Carnosaur}}''
* ''Film/{{Wanted}}''
* ''Film/WorldWarZ''
* ''Anime/BlackButler'' season 2
* ''Theater/{{Wicked}}''
* ''Film/{{Godzilla 1998}}''; the director stated outright it was intended to be InNameOnly
* ''Film/EdgeOfTomorrow'', adapted from the light novel/manga ''LightNovel/AllYouNeedIsKill''
* ''Film/{{Clueless}}'' from ''Literature/{{Emma}}''
* ''WebVideo/TheLizzieBennetDiaries'' from ''Literature/PrideAndPrejudice''
* ''Film/TenThingsIHateAboutYou'' from Shakespeare's ''Theater/{{Othello}}''

!! Special Cases:
* ''Simon Birch'', the film adaptation of ''Literature/APrayerForOwenMeany'', goes from Type 1 to Type 5 '' as the story progresses'', passing through almost every type along the way.
* {{Power Rangers}} has varied in faithfulness to {{Super Sentai}} from season to season. They range from being as similar as a 4 (''[[Series/PowerRangersWildForce Wild Force]]'', ''[[Series/PowerRangersSamurai Samurai]]'') to as different as a 1 (''[[Series/PowerRangersInSpace In Space]]'', ''[[Series/PowerRangersRPM RPM]]'').
* The 1934 Betty Boop cartoon WesternAnimation/SnowWhite starts off as Type 4, but drifts into Type 1 around the middle.
* Film adaptations of ''Literature/LesMiserables'' run the gamut from Type 4 (1934, 1958, 1978) to Type 3 (1982) to Type 2 (1998, 2012) to borderline Type 1 (1935, 1948, 1952).
** While the 1935 version is possibly the most unfaithful of all the adaptations, many people still consider it [[TropesAreTools a classic in its own right]] because of great performances from Creator/FredricMarch as Valjean and Creator/CharlesLaughton as Javert, as well as the GrandfatherClause (it was made during the HaysCode era, so they couldn't get away with much).
* Disney/TheAdventuresOfIchabodAndMrToad: ''The Wind in the Willows'' segment scores a 2, and ''The Legend of Sleepy Hollow'' segment scores about a 3 (almost a 4).
* Adaptations of the Franchise/{{Pokemon}} games fall all over the scale, though so far none have quite reached the extremes of 1 or 5. Of the more widely-known adaptations:
** The [[Anime/{{Pokemon}} original anime]] is a type 3 with heavy type 2 leanings, with exactly ''how'' heavy depending on the circumstances; most of the basics of the world of the games are there and the show adapts parts of the plots of the games to at least some extent suiting its format (collecting badges to face the League, fighting the evil teams of each generation), but there's a ''lot'' of AdaptationExpansion and the fine details of it all can get a fair bit different from the games.
** ''Manga/PokemonSpecial'' is very much a type 3, but has shades of Type 4 and Type 2 in its interpretation of certain aspects of the 'verse, certain characters, and certain plotlines (Type 2 for the latter two being more common [[EarlyInstallmentWeirdness early on.]]
** ''Anime/PokemonOrigins'' is a blatant Type 4 (and [[InvokedTrope deliberately designed as one]]) of [[VideoGame/PokemonRedAndBlue the original pair of games]]. There are still several things preventing it from being a Type 5, however, the most notable being [[spoiler:the franchise debut of Mega Charizard X.]]
* Most notably the ''Franchise/MarvelCinematicUniverse''. While most people would agree it's usually a 3, there are some movies that hit 4 (using a lot of elements from the comics as they were, i.e. The Super Soldier serum), with others that hit the 2 area (removing or heavily altering comic book elements, i.e. how Pym Particles work).
!!Patterns:
* The older and more established the original work is, and the more existing film adaptations that have been done with it, the less "need" new adaptations will feel to stick closely to the original, and the more likely chance that they will take their own approaches. This is especially true if the work is in the PublicDomain, and that's why works by people like WilliamShakespeare, JaneAusten and CharlesDickens get so many [[SettingUpdate Setting Updates]] and reinterpretations.
* Musicals and more recent plays that get film adaptations tend to be relatively faithfully-adapted, other than for length. It helps that they're already adapted to a more similar medium (they have a script, they take into account the visual element in a way novels don't, etc.)
* Anime fall into some predictable patterns:
** Manga and novel adaptations that are of finished works tend to be in the 3-5 range, unless they are very old and established works with previous adaptations, in which case they might fall lower on the scale.
** Manga and novel adaptations of ongoing works vary based on what the original creator and the studio want them to do with it. If they just stop the story at a certain point (planning to animate more when there's more if the show does well enough), they're usually type 4-5. If they stall for time using "filler arcs" (see: ''{{Naruto}}'' and ''OnePiece''), the presence of those fits them into type 3. Series that get anime-original endings vary based on how early the ending is established, varying from type 2-3 depending on that.
** Video game and VisualNovel adaptations necessarily have to make some changes to turn a branching story into a linear one, so they usually fall in the 2-3 range. In the case of some mobile or card game adaptations, they might have to make up a story from scratch where the original didn't have one, falling into type 1.
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