This phenomenon works thusly:

# In the original work ''AliceAndBob,'' there is a specific explanation for some plot point. For example, Alice always knows what to get Bob for his birthday because she has latent PsychicPowers.
# ''Alice and Bob'' is adapted to a new medium--say, [[TheMovie film.]]
# The fact that Alice always gets Bob the right gift stays, but her latent psychic powers don't. There is no longer any explanation for why she does this.

This isn't limited to major elements of the work; often times minor things will get thrown in to satisfy the fans who might be looking for it but the explanation is left out because it's not important to the adaptation. This can reduce something to the point of a HandWave, but it [[TropesAreTools isn't all bad.]] If something was not that important to the original work, this helps with the ConservationOfDetail and prevents the audience from getting overloaded. However, if done poorly, it can accidentally create an AdaptationInducedPlotHole.

This is a kind of partial AdaptationDistillation where the explanation is removed in the distillation process but the element it explains isn't. If it's important and done excessively, might lead to ContinuityLockout.
----
!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* In the manga version of ''Manga/{{Berserk}}'', it's shown ''very clearly'' as to why Guts doesn't like being touched [[spoiler: because he was raped as a child]] and three scenes show his severe dislike of this: first being when a general taps him on the shoulder after a battle, second when Casca is warming Guts when he fell ill after fighting Griffith, and third when he was carried by Pippin [[PlayedForLaughs for laughs]]. In the anime adaptation, these scenes occur... but it's never explained why he doesn't like being touched because [[spoiler: the rape portion of his flashback doesn't occur in the anime.]]
** Parodied in ''BerserkAbridged'', where Guts wonders during a nightmare whether it's symbolic of something. [[spoiler:A panel from the rape scene appears]], and Guts vows to get back to work repressing it in the morning.
* In ''BraveStory,'' Wataru (the main character) and Mitsuru (TheRival) are both racing to reach the place called the Tower of the Goddess and recieve a wish from her. In TheFilmOfTheBook, it's never explicitly explained why it's important who gets there first, or if it is. In the book, it's much more clear: [[spoiler: Whoever makes it last will be sacrificed to keep the land of Vision in existence.]]
* Happens ''twice'' in the film version of ''Anime/HowlsMovingCastle:''
** In them both, Sophie decides to stay at her hat shop as the eldest child. In the book, it's because she's ([[WrongGenreSavvy Wrong]]) GenreSavvy about YoungestChildWins. In the movie, she simply says she's staying because she's the eldest--leaving the audience to assume something involving inheritance or a misguided sense of responsibility, possibly.
** At the end of both, [[spoiler: when she has to return Howl's heart,]] she wants to know if Calcifer will still be alright. He says he will. In the book, it's explicitly because [[spoiler: Sophie can imbue things with magical powers just by talking to them, so she gave Calcifer a life of his own outside of Howl's heart.]] In the movie, it's {{Hand Wave}}d with Calcifer simply thinking Sophie is special somehow.
* The ''Manga/{{Negima}}: Another World'' {{OVA}}s don't even bother to explain the whole [[OvernightAgeUp age-changing pills]] deal, confusing viewers who see Chisame and Chachamaru are now lolis... just because.
* If you only watch the anime adaptation of ''LightNovel/ShakuganNoShana'', [[spoiler: you might wonder where the Snake of the Festival came from, and what motivated Yuuji to betray the Flame Hazes. This was foreshadowed early in the novels.]]
* In the manga of ''Manga/YuruYuri'', the girls decide to find (often silly) solutions for increasing Akari's popularity, after she had barely appeared in the last few chapters. In the anime adaptation they do this ''in the first episode already'', [[DecoyProtagonist even though Akari appears to be the main character]], which makes it look like they are merely bullying poor Akari for no good reason.
* ''[[Anime/TheIdolmaster The Idolm@ster]]'' - Some events in the anime series make a lot more sense if you've played through the game and unlocked the backstories for the idols.
* The ''VisualNovel/FateStayNight'' anime only follows the ''Fate'' route from the visual novel, which never explains the reasons behind Shirou's MartyrWithoutACause tendencies, causing him to come across as [[TooDumbToLive an unbelievable idiot.]]
** Many other things pop up without full explanation, such as when Shirou conjures the same swords that Archer used, or why Sakura was kidnapped by Caster.
** The same tendency is carried UpToEleven in the ''Unlimited Blade Works'' movie, which is very much intended as eye candy for those who played the VN, rather than a work in itself. The nature of Heroic Spirits is never explained, beyond "they're what you summon for the Grail War", making [[spoiler:the revelation of Archer's identity]] into a complete AssPull; it preserves the emotional context surrounding [[spoiler:Shirou [[DeusSexMachina establishing a contract]] with Rin]] while replacing the scene itself, making it seem as if Rin turned into a complete bitch for no reason for a single scene and then reverted; among other problems.
** The ''LightNovel/FateZero'' anime is much better when it comes to this; however, it fails to explain exactly why Gilgamesh is infatuated with Saber (the light novel explains that she reminds him of Enkidu, his MoralityPet and OnlyFriend).
* In ''[[Manga/FullmetalAlchemist Fullmetal Alchemist: Brotherhood]]'', at one point in the series Envy turns into [=LanFan=] in order to get Ling Yao to lower his guard down and get eaten by Gluttony. In the manga, Envy personally fought the two and saw just how important she was to him, but the anime cuts this entire scene out and thus Envy never personally even encounters Ling prior to this scene. What saves it from being a complete plothole is we briefly see Envy spying on Ling and [=LanFan=] right before Gluttony goes crazy. This also is explained with why Envy transforms into [=LanFan=] masked in the manga and unmasked in the anime: in the manga when they fought she had her mask on the entire time, while in the anime it had been destroyed prior to him spying on everyone.
** During the episode where the baby gets born, Ed is furious with himself because he is useless during critical moments. This seems weird because he has no medical experience, so it shouldn't hit him that hard. Turns out, in the manga, Ed actually attempts (and fails) to build a bridge for Dominic to get the doctor. This, of course, makes more sense because it's within Ed's area of expertise.
* The anime of ''LightNovel/SwordArtOnline'' is an extremely faithful adaptation of the light novels, with one exception: Kirito's InnerMonologue is removed almost completely. While there are a few important plot points that become confusing due to this omission, mostly we just lose a few jokes. Internally, he makes constant game references, reveals that he wears mostly black due to a simple fanboyish belief that black is cool, continues using Liz's sword [[NamedWeapons Dark Repulsor]] simply because he thinks the name ''dark repulsor'' means the sword is fated to defeat the final boss, and that he memorized a number of placating lines for if he ever found himself in an AccidentalPervert situation (and promptly forgot them when it actually happened).
* In adapting ''Anime/PuellaMagiMadokaMagica'' to film, a few scenes were cut that apparently just weren't important enough yet provided important exposition nevertheless. This includes magical girls being able to telepathically talk to each other via Kyubey, the nature of familiars, and [[spoiler:why Homura's struggle with mathematics and track-and-field is important as they removed the first episode scene where she did both effortlessly.]].
* In the first anime arc ''LightNovel/ACertainMagicalIndex'', Touma has [[TalkingIsAFreeAction enough time to make an incredibly long speech]] while running across a tiny room. The novels, however, justify this because his opponent had used a spell to distort space. No such explanation is provided in the anime.
** The reason Aureolus missed Touma with his first two attacks or how Stiyl survived is not explained in the anime. In the novel, Stiyl explained that he was still alive after being flayed and used heat mirages to throw off Aureolus' aim; this caused the alchemist to doubt himself and made it impossible for him to fully control Ars Magna. Stiyl used the opportunity to restore his body.
* In the first light novel, ''LightNovel/{{Toradora}}'' has a bit of a digression into a tall tale from Yasuko about how she's a "mini-[[PsychicPowers esper]]" and can [[TeleportersAndTransporters teleport]] three times in her life; she says she's used up two of them, and [[ItOnlyWorksOnce Ryuuji can have the third time]]. He almost thinks he did, getting to Taiga in time to catch her from a bad fall. In the anime, well, he just catches her, and the "wait, what now?" moment of paranormality (which is never referenced again) is ignored.
* In ''Franchise/{{Digimon}}'' look at Greymon to [=MetalGreymon=] and compare pretty much any other evolution. His cybernetics are patchy and by all appearances incomplete and unprofessional looking compared to any other metal evolution. That's because the first [=MetalGreymon=] was actually a Greymon upgrading itself from battle damage.
* The ''Manga/OnePiece'' anime [[{{Bowdlerise}} cuts out]] a scene from the manga where Luffy as a child [[GoodScarsEvilScars scars himself]] to try and impress Shanks, thus it's never explained where he got such a scar.
* This occurs in the anime adaptation of ''Manga/AttackOnTitan''. In the anime, Eren is shown to have copied one of Annie's {{Signature Move}}s and is later stated to be one of the best at hand-to-hand-combat. That Annie was his teacher is left out, removing an important aspect of their relationship.
* ''VisualNovel/DanganRonpa: The Animation'' leaves out large chunks of dialogue that explain the significance of certain clues, but they are still used in the trial scenes. In particular, in case 2, [[spoiler: the dialogue that establishes that only one person could conceivably have found out how to destroy the electronic notebooks is left out.]]
* The 2001 adaptation of ''Manga/{{Cyborg009}}'' ended its TV run at episode 48, where [[spoiler: Joe and Jet appeared to die when they burnt up on re-entry to Earth]]. In the three-episode OVA arc that followed, both characters in question appeared relatively fine with no explanation of how they got out of the situation. This is due to the fact that aside from a loose adaptation of "God's War" (the OVA), the anime did not adapt beyond volume 10 and thus did not include the explanation for how the characters had survived.
* In the first ''LightNovel/HaiyoreNyarkoSan'' LightNovel, it's revealed that [[OrdinaryHighSchoolStudent Mahiro]] has the ability to perceive and resist shifts in space-time, which is how he was aware of the PocketDimension where Nodens sent Nyarko and Cuuko for their fight. This wasn't mentioned in the anime adaptation, which thus far covers novels 1-7 (plus bits of 11); however, it becomes an extremely important ChekhovsSkill later down the line, when [[spoiler:Nyarko and Cuuko are [[RetGone erased from history]] and Mahiro is the only one who can save them because he's the only one who even remembers they existed in the first place.]]
* Due to the anime for ''[[Manga/GokukokuNoBrynhildr Brynhildr in the Darkness]]'' condensing over thirty chapters of a major story arc into only a few episodes, many details are swept under the rug or handwaved. Most notably, a lot of explanation behind what exactly is happening with the aliens inside the witches, the full details on Hatsuna's ability to heal herself and others, how Kazumi is able to pull off high level Technopathy despite being relegated to B rank, and why the villain noted for their distinct lack of empathy decided to sacrifice himself for someone he freely admitted to not caring for. A deal where they get the recipe for an all important drug is also swapped out for the man trying to reverse engineer the drug miraculously figuring it out faster.
[[/folder]]

[[folder:Comic Books]]
* In pre-Flashpoint DCComics, Kyle Rayner was chosen by Ganthet to be the wielder of the only surviving Comicbook/GreenLantern ring, after Hal went mad, destroyed the Corps and killed the other Guardians - essentially because Ganthet didn't have any power to do a proper search for a worthy bearer, and Kyle was the first human he found. Years, later, Kyle restored the Guardians, making some of them female for the first time, and years after ''that'', Hal got an AuthorsSavingThrow and went back to being a GL, but his actions were still in place. In the NewFiftyTwo, we get a flashback to Kyle's early days as GL. The Corps is still around, as are the Guardians, and Ganthet's girlfriend Sayd appears to confirm that there have always been female Guardians. Kyle was still chosen by Ganthet, rather than the ring, but there's no indication as to ''why''.
[[/folder]]

[[folder:Films -- Animation]]
* ''WesternAnimation/JusticeLeagueTheFlashpointParadox'' ends just like the original ''Comicbook/{{Flashpoint}}'' comic, with TheFlash rebooting history into the Comicbook/{{New 52}} timeline. Thing is, the movie omits ''how this is possible'', since in the original comic, this was caused by Pandora tricking the Flash into merging the DCUniverse with the [[Comicbook/{{Vertigo}} Vertigo]] and {{Wildstorm}} universes. Both Pandora and the merger sequence ended up AdaptedOut, so there's no explanation given as to why Flash and Batman suddenly have new costumes at the end of the film.
* A mild case in regards to the name "Rapunzel" in Creator/{{Disney}}'s ''Disney/{{Tangled}}''. The film completely rewrites the beginning of the original fairytale in which Rapunzel's father sneaks into the witch's garden to steal the rampion that his pregnant wife craves. When he is caught by the witch, she offers him his life in exchange for his newborn daughter, a deal that he is forced to accept. Thus, the witch calls her daughter Rapunzel, another name for the rampion that was used to claim her. In ''Tangled'' this entire story is replaced with one in which Rapunzel has magical hair derived from a flower that was given to her sick mother. There is no rampion whatsoever, and Rapunzel is just the really strange name that her birth parents give her.
* In ''Franchise/{{Bionicle}} 2'', the heroes never showcase possessing any elemental powers, until the very end when they unite them to defeat the villain. It's never explained why they don't use them in any other scene, making the ending come of as an AssPull. They have actually used up all their powers in the books that the movie entirely glosses over, and can only use them in the final scene because that's how long it took for them to "refill".
[[/folder]]

[[folder:Films -- Live-Action]]
* The largely unexplained backstory to ''Film/TheLordOfTheRings'' leaves quite a few of these.
** Many who haven't read the books wonder why, if the ring was so evil, and Isildur wouldn't destroy it, Elrond didn't just grab it from him and destroy it himself, or even just push Isildur into the lava. In the books, no-one at that time is sure of exactly what the ring does, Elrond included; they have no idea that it's keeping Sauron alive. Isildur takes the ring as a memorial of their victory, and no-one really has any reason to oppose him doing so.
** No explanation is given in the films as to how Arwen gives up her immortality. In the books, she can do this because Elrond is half-human and so the Valar offered him and his children the choice to become human at any point.
** The issue of Aragorn as heir to the throne of Gondor. If Boromir can recognise the heir of Isildur simply from the name 'Aragorn', then why isn't he king already? In the books, the issue is far more complicated; while Aragorn is the only surviving heir, he's only distantly related to the old Kings of Gondor, and he also comes from a line that had previously been excluded from the Gondorian succession.
** One issue that is routinely brought up as though it's a plot hole is "Why didn't the Fellowship just use the eagles and fly the One Ring to Mount Doom, then drop it in from the air?" There are a number of reasons in the books that explain why. The Eagles are forbidden by their creator from intervening directly in the War, so they won't shepherd the Ring themselves. They also would be just as likely to be tempted to take the Ring for themselves as any other sentient creature. The most obvious reason is that the whole point of the Fellowship is to avoid detection, and a flock of eagles would bring all of Sauron's forces down on their heads. For all these reasons, the Eagles are only free to arrive once the Ring is gone and Sauron is defeated.
* When Creator/StanleyKubrick adapted ''Film/TheShining'', he did this with several plot points. Kubrick cut out the explanation of who "Tony" is, the story of the dead lady in the bathtub, and the story of the fellow in the dog costume that Horace Derwent debases--but he left all of those moments in the movie, without explanation. He also revised the story's climax, cutting out the exploding boiler, but still took care to show the boiler in a couple of scenes. It's fairly likely that the absence of explanation for most of these elements was deliberate, though, [[TropesAreTools since the lack of exposition adds to the film's mystery and ability to shock the audience.]]
* David Lynch's adaptation of ''Film/{{Dune}}'' is one big mess of this. Hardly anything is given a proper explanation, and the film even features a few setups to plot threads whose payoffs are not included.
* The ''Film/HarryPotter'' films from the third one onwards are full of these. One major reason why this series is so guilty of this is that the book series was still ongoing while the films were being made, so the scriptwriters had no idea what bits might provide pertinent background for future events.
** The movie adaptation of "Prisoner of Azkaban" never bothered to explain that the Marauders were [[spoiler:James Potter, Remus Lupin, Sirius Black, and Peter Pettigrew]]. This makes Lupin's sudden knowledge of exactly what the Marauder's Map does inexplicable, as well as Sirius instantly knowing what the map is when it's brought up later on in the film. Besides, it leaves the map itself a silly unexplained plot device out of nowhere instead of something perfectly intertwined in the rest of the story. Harry dropping Sirius' nickname in the 5th film (as well as Pettigrew being called by his) also comes out of nowhere without the Marauder backstory.
** The movies also never explain how Sirius Black escaped from Azkaban, but leaves in that it's a mystery how he escaped, as no one else ever has.
** In the second book, Harry, hiding in a cupboard in a Diagon Alley shop, overhears a conversation that becomes crucial in a later book. In the movie, he still enters the shop, gets his arm caught by one of the shop's products, and then immediately leaves, making the scene rather pointless. Harry does overhear the conversation in the extended version of the film.
** In ''Literature/HarryPotterAndTheGobletOfFire'', the only witness who can corroborate Harry's account of [[spoiler: Voldemort returning]] is Barty Crouch Jr. In the book, the malicious/incompetent Minister for Magic [[spoiler: brings a dementor to defend him, which [[FateWorseThanDeath sucks out Crouch's soul]]]]. Harry is disbelieved for most of ''Literature/HarryPotterAndTheOrderOfThePhoenix''. In the film, this isn't brought up, leading a savvy viewer to wonder why nobody believes Harry.
** Additional one from "Goblet of Fire" is the fact that Harry gets his winnings from the Triwizard Tournament then gives them to the twins because "people are going to need a laugh soon." This gives them the funding for the (otherwise dirt poor) Weasleys to start the shop once they quit school. With the films they just suddenly manage to make enough in a few short months to have a big shop already established in Diagon Alley.
*** Although they are shown selling products at school and taking bets on the Triwizard Tournament, and this time [[spoiler:no one steals their winnings.]]
** There's also the scene from "The Order of the Phoenix" where Harry & co. are rounded up by Draco and his goons in Professor Umbridge's office. In the book, Neville, Luna, and Ginny cause a ruckus as a distraction in the group's thought-out plan to sneak Harry into the office, but in the movie they outright skip the planning scenes and don't even hint at the trio's involvement. Draco simply brings them in, says "we caught 'em", without an explanation as to why they were caught.
** The movies never explain that Sirius willed his house - and by extension Kreacher - to Harry. So there's no explanation in ''The Deathly Hallows Part 1'', when Kreacher obeys Harry's every command (despite his clear distaste for Ron and Hermione). Of course, if the director of ''Order of the Phoenix'' had cut Kreacher entirely as he originally intended, it would have made the scene even ''more'' incomprehensible to people unfamiliar with the books...
*** According to Potter lore, J.K. Rowling intervened during the development of the fifth film, cryptically telling the director--and by extension, readers--that Kreacher would be pivotal to the at-the-time-unreleased seventh book and needed to be kept in the movie.
** Strangely inverted at the end of the ''Half-Blood Prince'': Snape reveals - with every bit of dramaticism Alan Rickman can muster - that he is, in fact, the half-blood prince whose annotated potions textbook Harry had been learning from on the side. While this does explain the way he's able to save Draco from a spell that Harry would think nobody would know, the film leaves out the follow-up scene in which Snape asks Harry for his potions textbook, which clues the audience in beforehand that Snape at least knows about the existence of the Half Blood Prince's book and instead, the audience is left wondering just why he's so damn ''serious'' about such a thing. That's because it's basically mentioned once in the movie; in the book the search for who the "prince" really is acts as the ''main subplot'', getting quite nearly as much time as the main plot itself.
** Several scenes of ''Half-Blood Prince'' explaining Voldemort's background are missing, in particular, the scenes relating to which items he made into Horcruxes, making the nature of the Horcruxes in the subsequent movies seem much more random.
** Also, if recalled correctly, there isn't a lot of explanation to why Dumbledore [[spoiler: knew a horcrux would be lurking in that cave in the Half-Blood Prince film. Yes, a photo of the very cave is seen in Tom Riddle's childhood thus why Dumbledore would logically suspect its correct hiding place, but it's easy to miss and the "field trip" is not touched upon.]]
** In the seventh film the question Lupin asks Harry to make sure he's not an impostor (what creature was in his office when Harry first visited) doesn't really make sense since Harry isn't shown in Lupin's office until the very end of the 3rd film and they spend all their scenes together out walking in the forest.
** The shard of the mirror Harry broke in the end of the book of ''Order of the Phoenix'' magically appears in the final films and is every bit as useful as it was in the books - but with no prior explanation.
** In the fifth film, Mr. Weasley is shown taking Harry to the Ministry of Magic by way of an elevator disguised as a phone booth. This seems to be an odd and impractical way to get there, especially since as soon as they step out of the elevator, people are shown [[TeleportersAndTransporters Apparating]] and using Floo Powder to arrive at the Ministry. In the book, it's explained that Mr. Weasley thought, since Harry is up on charges of illegally using magic, arriving at the Ministry in as non-magical a way as possible would give a good first impression.
** At the beginning of the eighth film, which adapted the second half of the seventh book, the main characters attempt to break into the wizard bank Gringotts by having Hermione impersonate Bellatrix Lestrange using Polyjuice Potion. At the end of the previous film, they had defeated Bellatrix and obtained her wand (which can work like ID in the wizarding world). In the book, it's explained that the Gringotts staff probably know that Bellatrix was attacked and ask Hermione for her wand as a trap (if she has it, it proves that she's a fake Bellatrix). In the film, this is not explained at all, but there is still a huge amount of dramatic tension when the Gringotts goblin asks for the wand, leaving the viewer to wonder why everyone is acting worried when they clearly recovered the wand at the end of the last film.
** The films do explain the connection between Harry's wand and Voldemort's, but leave out Dumbledore's speculation that this connection had extended beyond the wands and to their users, causing Harry's wand to "recognize" Voldemort and defend Harry against him. This can leave movie viewers wondering why Voldemort's attempt to subvert the connection by using Lucius Malfoy's wand instead of his own didn't work.
* ''Film/{{X-Men}}'':
** In both the comics and films, Magneto's intentions seem to change quite a bit, but in the comics the greater development of his background as a Holocaust survivor was generally used to make him realise he was becoming just as bad as the Nazis, and to shift him away from advocating genocide of all non-mutants. In at least the second film (the first and third leave it ambiguous) however, Magneto retains the seemingly contradictory positions of being both an advocate and a victim of genocide.
** The film version of ''Film/XMenDaysOfFuturePast'' skips some of the details of how the BadFuture came to be, never actually explaining why [[KillerRobot the Sentinels]] went from hunting down Mutants to conquering the whole of humanity. In the original comic book storyline, it was explained as a severe case of GoneHorriblyRight: the US military wanted the Sentinels to contain the Mutant threat, but didn't consider how many normal humans were passive carriers of the X-gene. In order to fulfill their orders, the Sentinels had to [[TurnedAgainstTheirMasters betray their own creators]] to ensure that the X-gene didn't contaminate the human gene pool.
*** Actually Logan explains to Beast and Professor X that the sentinels began to kill anyone who had the potential of having children who are mutants, then anyone who had the potential of having mutants grand-kids, as well as anyone who fought alongside mutants.
* ''Film/JurassicPark'' the movie is occasionally criticized for the film claiming its moral is about the unpredictability of nature, when it was really all [[spoiler:the programmer Nedry's]] fault. [[Literature/JurassicPark The book]] covers this by showing evidence from the park's own data that the populations were indeed out of control. [[spoiler:Nedry]] wasn't the cause of the collapse, but he was the final crack to the foundation.
** The movie ''does'' bother to show that one fairly important part of the park's control system failed for reasons entirely unrelated to [[spoiler: Nedry]]: [[spoiler: the dinosaurs are supposed to be kept from breeding on their by all being female, but evidence is found that for [[GenderBender one reason]] or [[TrulySingleParent another]], that hasn't been quite as effective as thought...]]
** The famous sick-triceratops scene also reproduces enough information from the book to infer, if you've read it, that [[spoiler: some of the dinosaurs are eating toxic plants, despite the efforts of the park to manage the park's flora.]] However, the lycene contingency is mentioned [[spoiler: without reference to the trouble it ends up causing in the book.]]
** The first book ended with Nublar island being carpet-bombed by the (funnily non-existent) Costa Rican airforce, hence Ingen's new ruling bureau's (and in the second book, Biosyn's) need to go to the "Site B" and get their dinosaurs there. This was actually explained in a scene of the ''Lost World'' movie but was left out of the theatrical cut, leaving the casual viewer wondering why Ingen didn't just go back to Nublar, the island with some working infraestructure left and pick some of the dinosaurs still penned up there, rather than massing "two dozen cowboys" and going to catch the entirely free ones in Sorna.
* In the original novel which ''Film/WhoFramedRogerRabbit'' is based on, the book's surprise ending contains an explanation for the seemingly implausible pairing of Jessica and Roger. As the plot of the novel is completely different from the film, however, the movie's version of the Jessica/Roger relationship is simply treated as a sort of strange, funny thing that defies logic.
* In ''Literature/TheLionTheWitchAndTheWardrobe'', after the kids become kings and queens of Narnia, the narration tells how they ruled successfully for years and years and were given nicknames: King Peter {{the Magnificent}}, Queen Susan the Gentle, King Edmund the Just, Queen Lucy the Valiant. [[Film/TheChroniclesOfNarnia In the film of the book]], they're crowned with these names while still kids just after winning their victory, which makes them seem slightly ridiculous and over-the-top -- especially in the case of Edmund, whose main contribution to the plot was betraying his siblings to the White Witch before he got better.
** It's also explained in the book that the White Witch's Turkish Delight [[VerySpecialEpisode instantly addictive]], making Edmund's betrayal over a supply of candy seem far less petty.
* ''Film/StarshipTroopers'', adaptation of ''Literature/StarshipTroopers'' had the Mobile Infantry fighting battles that were ''extremely'' unsound tactically. Infantry, unsupported by armor or artillery, making direct frontal attacks on a numerically-superior enemy? HollywoodTactics at their worst. ''However'', it's also true to the book... sort of. The Mobile Infantry ''did'' operate without armor or artillery support, but only because their powered armor suits let the MI itself fill the traditional roles of [[SwissArmyWeapon armor, artillery, and even close air support (up to and including nuclear weapons.)]] When the powered armor was taken out of the movie, the justification for the MI operating unsupported went with it.
** There is artillery in the book, but it's a separate unit from the Mobile Infantry, and so gets glossed over by the narrator, who's generally more interested in describing only his small piece of the action.
** The film is a satire of patriotic propaganda, so that is most likely just a parody of HollywoodTactics.
* In ''Literature/{{Twilight}}'', Bella runs into some nasty characters who are going to hurt and possibly rape her. In the book, she has gotten lost by this point and does not know where to run, so prepares to scream and fight. It also says that if she tried to run, she would probably trip over her own feet. In the movie, she's still clumsy, but not ''that'' clumsy, and is still in sight of a reputable book store. Why she doesn't just turn around is not addressed.
** Also in the manga: in the book and movie, it's made pretty apparent that Edward is bothered by how Bella smells in their first biology class. In the manga, we get a few panels of him glaring pissily at her, which doesn't really indicate her smell being what's causing the issues and which leaves the panel where she sniffs her hair making her look like she has some nervous tick.
* Happens in TheRemake of ''Film/TheHaunting1999''. After Elenor has been thrown out of bed, she asks, "Who's holding my hand?" In [[Film/TheHaunting1963 the original movie]], this was spoken at the end of a rather tense scene in which Elenor is convinced that Theo is holding her hand. However, it is revealed a moment later than Theo is on the other side of the room, and that no one was holding her hand. It is used out of context and without explanation in the remake, as there is no one in the room with Elenor, nor did she imply at any point that someone was holding her hand before she asked the question.
* In ''Film/SpiderMan3'', Peter gains his infamous black symbiote but other than adapting to his costume and making him more hostile, the nature of the symbiote is not explained that much. When it comes time for Eddie Brock to put on the costume, there is no explanation given as to why he now has spider-powers and the audience is left to assume based on the comics.
** The movie also adapts the scene from the comics where Peter removes the symbiote in a church bell tower. In the comics, Peter did so because he knew from past experience about the symbiote's weakness to sonic vibrations and had no choice but to go to the tower. However, Peter doesn't figure out the symbiote's weakness until well-after he went to the bell tower - meaning he had no real reason to go there other than because of the comics. (The symbiote's weakness is clearly hinted at during this scene for viewers' benefit, but Peter doesn't put the pieces together until his final battle with Venom - which is several scenes after the fact.)
** In the film, Eddie is in the church because he is [[PrayerOfMalice praying that God will kill Peter]], which seems a ridiculously extreme reaction - yes, Peter cost him his job and wasn't exactly nice about it, but the two were competing for one position and losing your job is hardly something to kill someone over. In the comics, on the other hand, Eddie is there to seek forgiveness. Peter ''does'' cause Eddie to lose his job, but as Spider-Man rather than Peter Parker. Subsequently, in the comics Venom hates Spider-Man in his own right, rather than because he's Peter Parker.
* In the film of ''Film/ThePrincessBride'', Buttercup is somewhat confusingly presented to the populace as a princess when she's betrothed, but not yet married, to Prince Humperdinck. The book explains that she was declared princess-by-fiat of some little backwater principality just so that Humperdinck wouldn't be marrying a commoner.
* In the original ''{{Congo}}'' novel, Karen is a CorruptCorporateExecutive whose only interest is finding diamonds for her firm. She loads an abandoned mine with dynamite near a dormant volcano in an effort to locate more diamonds and the resulting explosion triggers an eruption that [[CollapsingLair destroys the abandoned city]] and forces them to OutrunTheFireball. In the film, her character is a lot more sympathetic, the reason she joins the expedition is to find her CanonForeigner boyfriend who was in an earlier expedition that vanished and the dynamite thing doesn't happen. The great eruption in the film is reduced to a random coincidence.
* One of these shows up in the film version of ''AScannerDarkly''. In the novel, Bob and friends freak out and get angry because Barris brings home an 18 speed bike he bought from someone, but Luckman only counts 9 gears (6 in back, 3 in front), leading them to think Barris got ripped off. Later, when Bob gets debriefed by his superiors, he's told that they're pulling him out because the drugs he uses while undercover are starting to effect his brain too much. They saw the group's reaction to the bike gears, due to the house being under surveillance, and they explain to Bob that the problem was that the group was adding the two sets of gears instead of multiplying them, which is how multiple speed bikes work. Bob's inability to figure out the problem indicates to them that his cognitive faculties are being erroded along with the other users. In the movie, this is not brought up in the debrifing, and the bicycle scene remains somewhat bizarre and unexplained.
** In a scene where the characters are riding in a tow truck after their car broke down on the highway, Luckman says "If I'd known it was harmless, I would have killed it myself." In the book, the statement is explained via {{Flashback}} as an in-joke among the group about how different classes of people view the world differently.[[labelnote:More detail]]At one time they hung out with a rich girl because she'd buy them drugs they normally couldn't afford, and she hung out with them so she could [[SlummingIt pretend she was part of the drug culture]]. One day she saw a bug crawling on a wall, and asked them to come in and kill it. They explained the bug wasn't dangerous, and in fact it's useful because it eats other bugs. She responded with the afore-mentioned quote.[[/labelnote]] In the movie, it just sounds like an incredibly random thing to say.
* Inverted in ''Film/JohnCarter'', the big screen adaptation of EdgarRiceBurroughs' ''JohnCarterOfMars''. The book never explains how Carter gets to Mars, vaguely referring to some sort of astral projection. The film has him finding a cave of gold and getting attacked by a [[HigherTechSpecies Thern]]. He shoots the Thern and takes his medallion, after the dying Thern has spoken a few words into it, causing it to glow. The Thern's last word is "Barsoom" (the Martian name for their planet), which John repeats while holding the medallion, activating the teleportation sequence. Also, it's not clear in the first book that John Carter's body on Mars is actually a duplicate, while his real body is still in that cave, unconscious and not aging. In the film, he figures it out after [[ActionGirl Dejah]] translates a few Thern symbols about halfway through the movie.
* ''Film/ScottPilgrimVsTheWorld'' includes the Subspace Doors from the graphic novels, but never explains what they are, despite being used during pretty important scenes. It isn't hugely jarring though, considering all the other non-sensical video game tropes and references that are just naturally part of story.
* In the film version of ''Film/TheHuntForRedOctober'', when Ryan is trying to convince his superiors that Ramius is defecting to the United States, he mentions that, "today is the first anniversary of his wife's death," leaving it unexplained why this is significant. [[Literature/TheHuntForRedOctober In the book]] his wife died due to a botched operation by a doctor who escaped punishment due to his Party connections, leading Ramius to decide that "the State must be made to pay".
** It is implied more subtly, and in a way more chillingly, in the coldly impersonal way Putin says "Her death was... unfortunate."
** There is also the fact that in the movie, [[AlternativeCharacterInterpretation it was implied that]] Ramius was more concerned about the possibility of his submarine being used as a first strike weapon than punishing the party for his wife's death. Mentioning his wife's death in this context was more about the issue that he no longer had anyone to go home to.
* In the 1997 adaptation of ''Literature/ALittlePrincess'', Sara wakes up to find her attic room filled with food, clothing and other luxuries. In the book, these things were brought to her in secret over a number of weeks by Ram Dass, the Indian man living next door, while she slept. In the film, they're just ''there'' with no explanation.
* ''Film/EndersGame'':
** In the film, the xenocide of the Formic species is [[MyGodWhatHaveIDone presented just as negatively as it was in the book]], but it's never actually explained that [[spoiler: the Formic War originally started because of an interspecies misunderstanding, as the HiveMind Formics were incapable of understanding humans' individual consciousness, and didn't realize that they were killing sentient beings until it was too late]]. In the film, everyone (Ender included) seems to agree that they're a legitimate menace, only questioning the methods used to defeat them.
** Ender's decision to [[spoiler: leave Earth to search for a new Formic home world]] also receives far less explanation than it did in the book, largely because of Peter and Valentine's side plot being cut. In the book, it was explained that the political situation on Earth [[YouCantGoHomeAgain made it impossible for Ender to return to Earth]], as the Second Warsaw Pact wanted him dead, and America and its allies wanted him on their side in the coming war with Russia. Also, it was explained that [[spoiler: the death of the Formics]] had led to an extraterrestrial colonization program, and that Ender had accepted an offer to govern a colony; in the movie, he just aimlessly goes off to [[WalkingTheEarth wander the cosmos]] alone, with no obvious destination in mind.
* The 1939 film version of ''Film/TheWizardOfOz'' portrays the Winged Monkeys as the unquestioningly loyal servants of the Wicked Witch of the West, but never wastes any time explaining ''how'' they came into her service (the fact that they're her {{Mooks}} is presumably enough explanation for most people). But Creator/LFrankBaum's original novel, ''Literature/TheWonderfulWizardOfOz'', specifically explained that the Monkeys were magically bound to obey the Witch's commands because she possessed a magical golden cap that gave her power over them. It also explained that they ''weren't'' technically her Mooks, as they were only required to obey three commands from the bearer of the golden cap; the Witch used up her last command when she had the Monkeys capture Dorothy and her friends.
[[/folder]]

[[folder:Live-Action TV]]
* ''Series/GameOfThrones''
** In [[Literature/ASongOfIceAndFire the books]], Khal Drogo removes Mirri Maz Dur's poultice, relies on the Dothraki healers instead, and his wound gets infected. This lends some credibility to Mirri, who criticized the Dothraki methods. In the TV series, they use Mirri's method, Drogo gets infected anyway, and Danaerys still trusts her to heal him. [[spoiler:It's even heavily hinted that Mirri wanted him to die]]. It all makes Dany seem naive and oddly trusting of someone she knows little about.
** In the second season, The Hound offers to help Sansa escape while he's fleeing the city. She refuses, as she does in the books. In the books her situation is less perilous and she already has a plot to escape of her own. In the show, however, she has no other alternative, so there's no motive for her to refuse so out of hand.
*** There is also the fact that the Hound is given little if any reason to go to Sansa's room. In the novel, the two have many scenes together, and the Hound seems to warm to her somewhat. It is actually he who directly tells Sansa the story of what happened to his face, something he never would do with anyone else, and he also storms back into the rabid crowd to rescue her without anyone asking him, implying that he genuinely cares for her. In the television series, he shows her exactly ''one'' moment of kindness, if it can even be called that, and only goes to rescue Sansa from the crowd after Ser Meryn refuses. Having shown Sansa no special attention in the TV series, it comes off rather strangely that after abandoning the king, his first act is to go to her room and try and convince her to come with him.
* In ''TheWorstWitch'' it's explained that it's tradition for the teachers and pupils to wear their hair loose at the Halloween celebrations. In season 1's HalloweenEpisode, this doesn't happen except for Miss Hardbroom. In season 2 it's only implied to be Halloween and there's no reason why all the girls are wearing their hair down for the celebrations. Especially since they're normally only ever shown with it down when they're in their nightgowns.
* ''Franchise/PowerRangers'' has had a couple of unexplained holdovers from ''Franchise/SuperSentai'':
** In [[Series/PowerRangersLightspeedRescue Lightspeed Rescue]], Diabolico and Olympius have a rather strange death scene where after they explode, a demon face shoots out of them, screams and explodes. This is because in the Gogo V version of this scene, the ghost of Bansheera's counterpart Grandienne was possessing them and died with them (this scene was Gogo Vs' final battle).
** In [[Series/JukenSentaiGekiranger Gekiranger]] and [[Series/PowerRangersJungleFury Jungle Fury]], monsters come in either alive (most of the major villains) or undead (most of the monsters-of-the-week, created from undead {{Mooks}} called Rinshi who are upgraded, gaining the ability to turn into the MonsterOfTheWeek at will) and have different deaths depending on this; live monsters get the standard fiery explosion, while undead freeze into statues and explode into dust, shattering just like the Rinshi they're made from. There's an early episode where a monster ''appears'' to die with the standard explosion multiple times, but isn't dead for real until he shatters. The difference is, Jungle Fury keeps several stories much the same as Gekiranger but doesn't make it especially clear when a monster is ''not'' a Rinshi Beast. Usually it doesn't matter much (It's not ''spelled out'' why Phantom Beasts and Grizzaka's underlings do not turn to dust, but there's no reason to think they're Rinshi to begin with.) However, in one episode, TheStarscream Naja has "life talons" that can restore him from near-fatal damage and resurrect others. He tries to tempt Camille with this. In Jungle Fury, it's not clear why that would appeal to her. If he joins her, they'd have "power over life and death," but only for as many resurrections as Naja has Life Talons; by the final WeCanRuleTogether speech at the climax, that's ''three.'' So not much temptation there. In Gekiranger, on the other hand, we get a detail that was left out of JF: ''Mele (Camille) herself is a Rinrinshi (Rinshi Beast),'' and talons from Braco (Naja) can make her ''truly'' alive. ''That'' is why it's so tempting. (It's also why, when he uses his first talon to save himself from Camille's poison, he instantly changes from Rinshi form into monster form: it's the first clue of what the talons can really do; ''he was no longer a Rinshi.'' It's ''also'' the reason why the two monsters he resurrects explode like monsters in other seasons when destroyed; ''they'' are also no longer Rinshi and so don't die like Rinshi. That's an important detail when a normal explosion instead of a Rinshi death meant ''the monster was still alive'' three or so episodes previously.)
** ''[[Series/PowerRangersOperationOverdrive Operation Overdrive]]'' inverts this; In [[Series/GoGoSentaiBoukenger Boukenger]], Gaja's {{Mook}}s, the Karths ("Chillers" in [=OO=]) are often seen being used by other villain factions without explanation. The [=OO=] episode "Just Like Me", which features one such battle from the Sentai version, has Flurious' flunky Norg bring "Chiller stones" to Moltor, which he uses in the fight against the Rangers.
[[/folder]]

[[folder:Videogames]]
* ''JumpStart3rdGrade's'' ProlongedPrologue was edited down in later releases. However, the line in the beginning of the game spoken by Polly, "There's still an extra credit question, and it's super hard" went down along with it. This now means that at the end of the game, her demand for the extra credit question seemingly comes out of left field.
* The PlayStation port of ''VideoGame/LEGOIsland 2'' had a few minigames removed due to space issues. One of these was a FishingMinigame, which is forgivable due to being boring beyond words. However, all mentions of it were inexplicably left in. This means that the minigame preceding it still has the pond at the end, and Pepper still tells Johnny, Pippin Reed, and Kilroy that he had caught a big fish.
* In the ''Franchise/PiratesOfTheCaribbean'' world of ''VideoGame/KingdomHeartsII'', Sora and co. seem to arrive during the Black Pearl's first attack - except Captain Jack is already out of his cell and trying to get a ship. Jack's debt to Will is still part of the reason he joins the party, but Will's reasons for letting him out in the first place are left kind of hazy.
** Gets even more complicated with [[{{Disney/TheLittleMermaid}} Atlantica]]: how the [[{{GoshDarnItToHeck}} heck]] did Eric find out Ariel's name? ''Kiss The Girl'' never happened because Sebastian was speaking with King Triton at the time, and the AlmostKiss came naturally.
* ''VideoGame/SeriousSam: The Second Encounter'' starts with a cutscene where the ship Sam found at the end of ''The First Encounter'' in space, barely making it out of Earth's atmosphere before a bus made out of crates carrying [[AuthorAvatar caricatures of Croteam]] crashes into it and forces it back down. In the ''HD'' remakes, this cutscene was removed, leaving almost no explanation for why the ship Sam was taking into space is now on fire and half-embedded into a cliff in ancient South America.
* ''[[VideoGame/SplinterCell Splinter Cell: Double Agent]]'' contains a variant example. The PS3 and XBox360 versions had an entire sub-plot surrounding a budding romance between Sam and Enrica. This entire plot was missing from the [[PragmaticAdaptation considerably different]] version released to PS2 and GameCube, [[spoiler:leading to something of a PlotHole when Sam abruptly becomes so protective of Enrica and no other [=JBA=] members when ordered to kill them in the final mission.]]
[[/folder]]

[[folder:Western Animation]]
* Early episodes of ''WesternAnimation/BatmanTheAnimatedSeries'' show a giant penny on display in the Bat Cave, purely because he has one in the comics, which he got during his one and only encounter with Joe Coyne, aka The Penny Plunderer. The Penny Plunderer never appears in the cartoon, but a later episode averts the trope by giving a new explanation: Two-Face had tried to kill Batman by tying Batman to the penny and then launching it into the air, and "they let him keep it."
** The "sequel" series ''[[WesternAnimation/BatmanTheAnimatedSeries The New Batman Adventures]]'' had a variation where certain stories from the tie-in comic ''ComicBook/TheBatmanAdventures'' were treated as canon for adapting into subsequent episodes, resulting in plot elements being established as "already happened" without prior explanation like Robin having split from Batman to pursue a solo career as the superhero Nightwing and Bruce Wayne's first encounter with Jason Blood/The Demon Etrigan before "The Demon Within", where he and Jason already know each-other. The series did adapt the Robin/Batman split in "Old Wounds" but that was only an adaptation of first 2 issues of "The Lost Years" which also detailed Dick's journey to Nightwing, including where he got the winged glider costume.
* ''WesternAnimation/BeastWars'' inverted this with the "Transmetal 2" toy line, so named because they were the 2nd wave of Transmetal action figures. In the cartoon, they give this an explanation: the PlotDevice of the Transmetal Driver is what creates the Transmetal 2 upgrades. However, some of the transformers adopted from the T2 line received their transmetal forms without the driver; thus they're not technically Transmetal 2's even though they're part of the same toy line.
* ''WesternAnimation/{{X-Men}}:'' Cyclops and Havok being immune to each-other's powers. While it was evident the writers were laying the groundwork for a reveal down the line of them discovering they were long lost brothers, they never got around to putting it in the series.
* ''SupermanTheAnimatedSeries:'' Sinestro's yellow ring: since the [[ImaginationBasedSuperpower Green Lantern Ring]] was not stated to be weak to yellow, it's not clear what exactly makes Sinestro so fearsome to other Comicbook/{{Green Lantern}}s that he could defeat so many and steal their rings.
** ''{{WesternAnimation/Justice League}}'' went the subtle route - although the Green Lanterns' weakness to yellow is never mentioned or alluded to verbally, pay close attention (especially in the first season) and you will see that nearly anything that happens to get through John Stewart's defenses happens to be yellow.
* The animated adaptation of ''Discworld/SoulMusic'' keeps the highly symbolic scene at the beginning when Imp has to choose between going to Ankh-Morpork or going to Quirm. However, it then moves the Quirm College for Young Ladies to Ankh, thereby seperating this choice from the fact that, once things have happened differently, he's working near the College.
[[/folder]]
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