History AdaptationExplanationExtrication / LiveActionFilms

* ''Film/Annihilation2018'': The expedition team is [[ImprobablyFemaleCast made up entirely of women]] for no apparent reason. In [[Literature/TheSouthernReachTrilogy the book]] it’s revealed that the Southern Reach deliberately arranged the team that way to introduce yet another variable into their experiments with the Shimmer, which is also why most of the members are scientists and why the previous expeditions had similarly odd rosters; they’re not expected to stop the Shimmer, [[UnwittingTestSubject they’re sent there to help the Reach learn its capabilities and behavior]]. The movie excises this ([[AdaptedOut along with almost everything else that happens with the Reach during the trip]]), with the result that the military seems to send a group of [[NonActionGuy untrained]] scientists charging into a lethal EldritchLocation just because.

* In ''Film/{{Cinderella 2015}}'', Gus Gus retains his name from [[Disney/{{Cinderella}} the animated film]], but no mention is given of his real name "Octavius," from which Augustus/Gus is a nickname of.

** Some viewers might wonder why everyone in Oz seems to accept the Wizard as the ruler of the Emerald City so casually, since he's an outsider who wasn't even born in Oz, and there must have been someone else ruling the Emerald City before he dropped in. For that matter, his departure can cause a bit of FridgeHorror when you think about the fact that he's essentially leaving a ''power vacuum'' in the capital of Oz, with no apparent plans to appoint a successor. The novel (and its sequels) explained both points: he named the Scarecrow as his successor before he left Oz, and it was later revealed that the previous ruler of Oz was a benevolent king named Pastoria who died shortly before the Wizard arrived, while his daughter Princess Ozma mysteriously vanished soon afterward. [[note]] The TwistEnding of ''Literature/TheMarvelousLandOfOz'' reveals that Ozma had her memories erased by an evil witch named Mombi, who transformed her into a young boy named "Tip" to hide her identity. Once Tip is unmasked as Ozma and turned back, she assumes the throne in the Emerald City again.[[/note]]

* Early in ''Literature/PercyJacksonAndTheLightningThief'', it's mentioned that Percy's sword, Riptide, is enchanted to always return to his pocket in the event that he drops or loses it, an explanation that was left out of the two film adaptations. However, the second film still includes a moment where, after being captured by Luke, he works the pen out of his pocket and uses it to escape his bonds, making it seem as though Luke tied him up without disarming him.

* Early in ''Literature/TheLightningThief'', it's mentioned that Percy's sword, Riptide, is enchanted to always return to his pocket in the event that he drops or loses it, an explanation that was left out of the two film adaptations. However, the second film still includes a moment where, after being captured by Luke, he works the pen out of his pocket and uses it to escape his bonds, making it seem as though Luke tied him up without disarming him.

** There's also no explanation for humanity's sudden technological advancements. In just a few decades, humans go from jet fighters being the epitome of aerial warfare to starships capable of beating the Formics back to their homeworld. We are left to assume ImportedAlienPhlebotinum thanks to all those Formic ships that fell from the sky. It's mostly the same in the books too, except the books feature ''two'' Formic invasions. However, even the First Invasion took place when humans already had hundreds of ships prowling the Solar System and gravity-manipulation technology (according to the prequels). The prequels also show the clear attempts to preserve the Formic ship for study and the foreknowledge of the impending arrival of the main Formic fleet (i.e. the Second Invasion).

* In the movie version of ''Theatre/PerfectPie'', Marie refuses to go swimming. In the play, this is because she’s been prone unpredictable seizures ever since she was a child and she’s afraid that she’ll have one while swimming and drown. In the movie, this trait was moved to her friend Patty, leaving Marie’s fear of swimming unexplained.

* The ''Series/MysteryScienceTheater3000'' episode version of ''Film/SpaceMutiny'' cuts out a small but important bit of dialogue where [[BigBad Kalgan]] explains the whole reason for wanting to mutiny and go to Corona Borealis is to sell the rest of the crew as slave to the pirates who live there. This has the unfortunate effect of making the mutineers UnintentionallySympathetic, as without this explanation it seems like they just want to go live on Corona Borealis, and the people in charge of the Southern Sun are forcing them to stay just [[BecauseISaidSo because they said so.

* 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.]]

** The Witch’s weakness against water was another example of this: in the book, it’s exposited early on that the two Wicked Witches are so old and shriveled that they’ve essentially been mummified, with all the fluid in their bodies having dried up long ago. This was why the Witch of the East disappeared after Dorothy’s house fell on her — her body literally crumbled away into dust — and why a pail of water caused the Witch of the West to melt away. Whereas in the movies, it’s just a weird, unexplained weakness of hers’.

** Some viewers might wonder why everyone in Oz seems to accept the Wizard as the ruler of the Emerald City so casually, since he's an outsider who wasn't even born in Oz, and there must have been someone else ruling the Emerald City before he dropped in. For that matter, his departure can cause a bit of FridgeHorror when you think about the fact that he's essentially leaving a ''power vacuum'' in the capital of Oz, with no apparent plans to appoint a successor. The novel (and its sequels) explained both points: he named the Scarecrow as his successor before he left Oz, and it was later revealed that the previous ruler of Oz was a benevolent king named Pastoria who died shortly before the Wizard arrived, while his daughter Princess Ozma mysteriously vanished soon afterward. [[note]]
The TwistEnding of ''Literature/TheMarvelousLandOfOz'' reveals that Ozma had her memories erased by an evil witch named Mombi, who transformed her into a young boy named "Tip" to hide her identity. Once Tip is unmasked as Ozma and turned back, she assumes the throne in the Emerald City again.[[/note]]

** Some viewers might wonder why everyone in Oz seems to accept the Wizard as the ruler of the Emerald City so casually, since he's an outsider who wasn't even born in Oz, and there must have been someone else ruling the Emerald City before he dropped in. For that matter, his departure can cause a bit of FridgeHorror when you think about the fact that he's essentially leaving a ''power vacuum'' in the capital of Oz, with no apparent plans to appoint a successor. The novel (and its sequels) explained both points: he named the Scarecrow as his successor before he left Oz, and it was later revealed that the previous ruler of Oz was a benevolent king named Pastoria who died shortly before the Wizard arrived, while his daughter Princess Ozma mysteriously vanished soon afterward. [[note]] The TwistEnding of ''Literature/TheMarvelousLandOfOz'' reveals that Ozma had her memories erased by an evil witch named Mombi, who transformed her into a young boy named "Tip" to hide her identity. Once Tip is unmasked as Ozma and turned back, she assumes the throne in the Emerald City again.[[/note]]

** In the first book, Gandalf stops at Edoras before going to Rivendell -- and learns that Grima Wormtongue has already begun poisoning Theoden's mind. This is left out of the film, so it's up in the air how Gandalf is so up to date on what's happening in Rohan.

** 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 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 some strange, funny case of DeliberateValuesDissonance between humans and toons.

** The original ''Film/XMen'' trilogy might leave some viewers wondering how Professor Xavier can afford a sprawling Westchester mansion with its own stealth jet--since he has no apparent source of income, and doesn't appear to charge tuition to his students. The comics explain that he's the heir to a vast family fortune, and the mansion is an ancestral manor that's been in his family for five generations.[[note]] May overlap with AdaptationInducedPlotHole, since the movies' version of Xavier appears to be ''British'', yet somehow apparently inherited a mansion in upstate New York.[[/note]]

* In ''Film/EdgeOfTomorrow'', soldiers use variety of guns but Rita Vrataski uses a CoolSword instead. Why she and only she is using a melee weapon is never explained. ''LightNovel/AllYouNeedIsKill'' from which the movie was adapted explains why. Guns have limited ammo which means no matter how good Rita will get she can only kill so much aliens in a single battle, and a melee weapon removes this limitation. On the other hand it's DifficultButAwesome to use and the only reason why Rita is capable of using it effectively is because she was stuck in GroundhogDayLoop and had as much time to train as she wanted.

* 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 the first book, Gandalf stops at Edoras before going to Rivendell - and learns that Grima Wormtongue has already begun poisoning Theoden's mind. This is left out of the film, so it's up in the air how Gandalf is so up to date on what's happening in Rohan.

* ''Film/{{She|1965}}'' (1965): [[{{Literature/She}} The novel]] has a complicated beginning descibing how Horace Holly gets drawn into the Vincey family quest to find a lost city in DarkestAfrica, and the months of preparation he and Leo Vincey take before setting out for Africa. The 1965 movie drops all of that and opens with Holly and Vincey, army buddies, already in Africa on unrelated business when the opportunity to search for a lost city is presented to them. As a result, it's just a convenient coincidence that Holly happens to know a lot of useful stuff about antiquity.

** 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.

* The film adaptation of ''Literature/{{Timeline}}'' foregoes the language difficulties presented in the book. In the book, the medieval characters speak a mixture of Middle English, Old French, Occitan and Latin, with the time travelers needing earpiece translators to understand them whilst they themselves struggled to be understood. In the film, the medievals simply speak modern English and French and have no trouble understanding the time travelers.

* In ''Film/VampireAcademy'', Lissa is tortured by an blind user to prevent her from using compulsion on him. However, this [[http://wlswarts.blogspot.com/2014/03/twilight-goes-to-hogwarts-for.html review]] points out that [[FridgeLogic why couldn't she heal his blindness just so she could compel him?]] This is because her hands are tied down, and her healing power only works through psychical contact such as by touch, which is out right explained in [[Literature/VampireAcademy the Book]] but only hinted at in the Movie.

** [[ColorCodedForYourConvenience The significance of various colors]] was always a central part of the Oz mythos in the books, as Oz was portrayed as a society built around the celebration of color and beauty. This is why some of the most iconic elements of the story are instantly identifiable by their color: Dorothy wears [[IconicOutfit a blue gingham dress and red ruby slippers]] [[note]] Though they were silver shoes in the book [[/note]], she travels along a yellow brick road to reach a city of green emeralds, there's a deliberate shot of a red brick road that leads in the opposite direction from the yellow brick road, and [[DeliberatelyMonochrome scenes in Oz are filmed in color while scenes in Kansas are filmed in monochrome]]. The movie retains the original book's striking use of color, but it generally doesn't explain ''why'' the various colors are significant. In the book, the Munchkins instantly trust Dorothy because she wears blue, which is the color of Munchkinland; various characters assume that Dorothy is a witch because her dress is patterned with white checks, and only sorceresses wear white; the Yellow Brick Road is yellow because it leads to Winkie Country (the land West of Munchkinland ruled by the Wicked Witch), whose color is yellow; the Red Brick Road in Munchkinland leads to Quadling Country, whose color is red; and the Emerald City is green because it's an independent capital city that lies at the center of the four regions of Oz, and thus has its own color.

** The original ''Film/XMen'' trilogy might leave some viewers wondering how Professor Xavier can afford a sprawling Westchester mansion with its own stealth jet--since he has no apparent source of income, and doesn't appear to charge tuition to his students. The comics explain that he's the heir to a vast family fortune, and the mansion is an ancestral manor that's been in his family for five generations.[[note]] May overlap with AdaptationInducedPlotHole, since the movies' version of Xavier appears to be ''British'', yet somehow inherited a mansion in upstate New York.[[/note]]

* ''Film/XMenApocalypse'' doesn't waste any time explaining how [[ComicBook/{{Storm}} Ororo Munroe]] wound up living in Egypt, despite being (by all appearances) of sub-Saharan African descent. The ''ComicBook/XMen'' comics explain that she was born in Harlem to an African-American father and a Kenyan mother, but moved to Cairo as a child.

** 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.

* 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/BladeRunner'': [[Literature/DoAndroidsDreamOfElectricSheep The book]] made a big deal about how real animals have almost died off and everyone is socially obliged to own one to show off their "empathy". The movie doesn't really explain this but keeps a couple of references to it, like the artificial owl and someone's reaction that collecting (and killing) butterflies would be a sick thing for a child to do.

* ''Film/TheChroniclesOfNarnia'':