Aladdin (2019): The film creates one not present in the original animated film when it comes to how Genie's wishes work. In the animated movie, Genie's wishes were granted in full consideration of the letter and spirit of the wisher, such as Aladdin's wish to be a prince immediately providing him with all the trappings of one, like a kingdom and an army of summoned servants, and Genie never makes any attempt to wiggle out of the terms of a wish, even when he has every reason to. The only wish that backfires in the film, Jafar's final wish to become a genie, does so because being a genie required him to be trapped in a lamp (something Jafar didn't realize in the moment), meaning the wish was flawed simply by definition. In this movie, Genie is instead written as a Literal Genie, in that he doesn't like people making vague wishes because of the fact it potentially leaves him the one needing to interpret what is being asked of him. He gives an example with Aladdin's "make me a prince" wish being vague enough that he could just summon a prince out of thin air and say it qualified. This is kept consistent through out all the film, except when Jafar wishes he to become the Sultan, which is granted like in the original animated movie, complete with the guards obeying him. Since the film never discusses what separates "make me a prince" from "make me the Sultan", and Genie never pushes back on the greyness of the wish, it creates a plothole about why the Literal Genie point is inconsistent with that wish, despite being introduced for this film, and being generally consistent elsewhere in the movie.note For example: Jafar is defeated because he wishes to be the most powerful being in the universe, which Genie exploits by making him a genie also, which is consistent with the Literal Genie plotpoint.
Harry Osborn's motivations for becoming the Green Goblin in The Amazing Spider-Man 2 seem rather weak due to alterations the film made to him, his father, and the Goblin identity itself. In the comics, Harry only became the New Goblin after many events that took years in comics and decades in real life, not the least of which was his dad, Norman Osborn, becoming the Green Goblin and dying fighting Spider-Man. In this continuity, there’s no Psycho Serum that both Goblins use, nor is the goblin motif a simple costume; Harry’s supervillainy is the result of normal Sanity Slippage as he tries to find a cure for a genetic disease that gives those afflicted by it Goblin-like features and (seemingly) kills Norman at the beginning. But in order for Harry and Norman to even remotely resemble their comic book counterparts, and to both reference how Norman was the Green Goblin in the comics and set him up as a Sequel Hook, he dies from the disease when he’s 63, while Harry is still in his twenties, making Harry’s increasing desperation over the course of, at most, months, seem rather unfounded. No one points out that he should have around 40 years to both enjoy life as a young billionaire, and let the multinational pharmaceutical company he’s heir to search for a cure.
Kayano's hair is brown instead of green in the Assassination Classroom live-action movie. This creates a plot hole after The Reveal that she's actually a moderately famous actress. In the manga, nobody recognized her because she dyed her hair green, so it begs the question how nobody in the movie recognized her.
While the original Battlefield Earth novel isn't exactly regarded as a masterpiece of plotting, the film still introduces various plot holes and problems of its own. Perhaps the most glaring is that the Psychlos somehow missed Fort Knox altogether in the film, whereas in the novel it was one of the first locations they hit. In the novel, the rebels acquire gold from an armored car stocked with bricks. The Psychlo sensors didn't notice the gold 1,000 years prior due to the car's frame blocking the scan. And they overlooked it while pulling gold fillings out of people's teeth because they assumed it was a military vehicle.
It is stated that Mike abducted Christine four months earlier, and since then has taken advantage of her amnesia to pretend to be her ex-husband Ben. In the book, the real Ben (who despite their divorce, still deeply cares for Christine) has not been aware of this because he has been working abroad for several months. The film, however, makes no reference to Ben having been away, but maintains the situation of him not having been in contact with Christine for a long time.
In the book, Christine's friend Claire does not realize and tell Christine that Mike is not Ben due to having been out of contact with Ben for years; she hadn't spoken to him to realise something was wrong. In the film, Claire is easily able to contact Ben, and their lack of contact is instead explained purely out of Claire's embarrassment about her affair with Ben.
The book makes it very clear that Mike is psychotic, which explains the considerable flaws in his efforts at deceiving Christine. The film does not really follow this portrayal of Mike, which leaves the view wondering why his actions are so obviously irrational and badly thought out.
Carnosaur: One of the few scenes lifted from the book to the first film was where a Deinonychus fatally mauls two teenagers in a car. In the book it makes sense as it's a man-sized adult animal, attacking at night, and it got to the couple so quickly because a car door was open. In the movie, due to added plot of the Deinonychus inexplicably growing fast across the duration, it's a juvenile about the same size as a small dog, attacks in broad daylight, and all the (fabric) car doors were shut. Thus a logical sequence becomes a confusing scene where an animal the size and danger level of a schnauzer tears through hard fabric in under a second, then kills two teenagers just as fast with neither able to flee or fight back.
The 2019 film version of Cats attempts to streamline the plot by giving Macavity a more prominent role in the story. As a result, he's introduced much earlier than in the play, and he kidnaps Jennyanydots, Bustopher Jones, Gus, and Skrimbleshanks after their songs instead of just kidnapping Old Deuteronomy at the climax. Despite this, Mistoffelees still only uses his magic to teleport Deuteronomy out of Macavity's lair—leading some viewers to wonder why he would leave the other four captives behind, and why the rest of the Jellicles seem to be perfectly alright with that.
In the film, a search for seven swords is superimposed over the novel's search for seven missing Telmarine lords. The claim that at least one of these swords was given to Caspian's father by Aslan is an Adaptation-Induced Plot Hole: Aslan hadn't been seen in Narnia for centuries prior to the events of Prince Caspian, and as a Telmarine, Caspian's dad would've been brought up to believe "Aslan" was either a myth or a monstrous lion-demon, not a benefactor.
The same film otherwise narrowly avoids another Plot Hole. On the Dufflepuds' island, Lucy gets kidnapped because only a girl can read the spell to break the enchantment. The film adds another girl, Gael, to the cast. However the Plot Hole is avoided when one of the Dufflepuds notes that Gael is also a girl — but they decide to kidnap Lucy because she has a book next to her, indicating she knows how to read.
In Dances with Wolves, a Sioux elder trusts his people to drive the American colonists away because he remembers that his ancestors successfully fought off the Spanish, the Mexicans, and the Texans before—even though none of these groups ever colonized Sioux land (the Sioux mainly live in the American Midwest). This is because the original novel was set in the American Southwest, and the natives were Comanche. When the movie was made, the studio had trouble finding actors that spoke Comanche, so they changed the natives to Sioux and moved the setting north, keeping the dialogue the same otherwise.
In the book, several characters discuss the possibility of the Church trying to hide evidence of Jesus having living descendants, but it's left ambiguous whether any of this is actually true, and the head of Opus Dei is ultimately revealed to be a pawn of "The Teacher" who just wants to keep Opus Dei afloat. In the movie, it's made explicit that there actually is a secret group within the Vatican called "The Council of Shadows" that actively wants to find and destroy Mary Magdalene's tomb, and they're particularly concerned about the possibility of someone using "DNA identification" to prove that Mary Magdalene was the mother of Jesus' children. Except...even if someone managed to get samples of Mary Magdalene's DNA from her tomb, no one could prove that Jesus fathered her children unless they also had DNA samples from Jesus himself. So what are they so afraid of?
In the book, Bezu Fache is just a really persistent detective who also happens to be a devout Catholic, and he pursues Langdon for Jacques Saunière's murder due to a simple misunderstanding. In the movie, Fache is a member of Opus Dei, and it's eventually revealed that Bishop Aringarosa is using him as a pawn to stop Langdon from exposing the truth about Jesus' bloodline (Fache suspects Langdon because Aringarosa falsely claimed that Langdon came to him in confession and admitted to being a killer). But Aringarosa has no way of knowing about Saunière's trail of clues, which is the only reason Langdon knows the truth—so Aringarosa shouldn't have any reason to be concerned about him revealing anything. Langdon also doesn’t find Saunière's clues until after he's summoned to the Louvre...but he's only summoned to the Louvre because Fache thinks he killed Saunière, and wants to set a trap for him. If Aringarosa was really the one who convinced Fache to pin the murder on Langdon, he'd had to have convinced him of that before Langdon even discovered the clues—in which case, he shouldn't have had any reason to frame him for murder.
The movie ends with the revelation that Sophie Neveu is Jesus' only living direct descendant. As Langdon rather melodramatically phrases it: "Sophie... youarethe secret!" In other words: a 2,000-year-old bloodline (descended from a couple who had multiple children) has exactly one living direct descendant. In the book, the final revelation is a lot less dramatic: Sophie and her long-lost brother (who's dead in the movie) are just two of several descendants of one of several French families who claim to trace their lineage back to Jesus and Mary Magdalene, and it's implied that Jesus and Mary Magdalene have so many descendants that being related to them isn't good for much other than bragging rights.
For added head-scratching: the movie also adds the revelation that Jacques Saunière wasn't really Sophie's grandfather, but simply adopted her to keep her safe from agents of the Church who systematically assassinate living descendants of Jesus (it's also heavily implied that the car crash that killed Sophie's parents was actually orchestrated by agents of the Vatican). But if Sophie is so important to the Priory of Sion that their leader adopted her to keep her safe from the Church, then why didn't any members of the Priory ever bother to check in on her after she became estranged from her "grandfather" as an adult? If the Priory of Sion is devoted to protecting the living descendants of Jesus, you'd think they'd put a little more effort into protecting his only living descendant. If nothing else, you'd think they might have told her about her secret heritage at some point, instead of just waiting for her to coincidentally stumble upon one of their hideouts.
In the book, "The Teacher" is able to manipulate Opus Dei into helping him because he learns that the Catholic Church is about to revoke its support for the group, and he convinces Bishop Aringarosa that he'll be able to regain the Church's support if he presents them with the Sangrael Documents (the historical documents that prove that Jesus had descendants). In the movie, the plot point about Opus Dei losing its Church support never comes up, and Aringarosa is part of a secret group within the Vatican that actively wants to hide the existence of Jesus' descendants from the world—making it extra questionable that he would willingly ally with the Teacher, who wants to reveal the existence of Jesus' descendants to the world. The movie's only explanation is that the Teacher (somehow) "convinced them that [he] was an ally".
In the movie, "The Teacher" asks his allies in the Church for a small fortune in Vatican bearer bonds solely so they'll think that he's Only in It for the Money and won't suspect that he has his own agenda—and they give him as much money as he wants (with seemingly little hesitation), even though they don't know who he is and have little reason to trust him. In the book, Aringarosa conveniently has a large stash of Vatican bearer bonds at his disposal due to the Vatican paying him severance money after revoking their support for Opus Dei, and he agrees to pay the Teacher because he convinces him that he can help him regain the Vatican's support if he finds evidence of Jesus' bloodline.
Dawn of the Dead (1978) was reworked into the very different film Zombi for European audiences, with a faster pace than the American version at the cost of a new plot hole. Originally, Roger and Peter succeed at their first round of barricading the mall doors with trucks, causing Roger to start celebrating while they're getting more trucks, get too cocky, and then get bitten by a zombie. Zombi skips over the first part so Roger's careless behavior comes out of nowhere before they've accomplished anything and is completely out of character.
The titular battle in Batman v Superman: Dawn of Justice is mostly based on the climactic fight in Batman: The Dark Knight Returns—but since the rest of the story is so different from the comic, the fight ends up making very little sense. In the comic, Superman and Batman are longtime friends driven to blows over ideological differences, and Batman only fights Superman to stall for time before Oliver Queen can incapacitate him with a kryptonite arrow. And despite their differences, neither of them actually wants to kill the other, so Superman spends the fight holding back his full strength to avoid crippling or killing Batman (which Batman exploits). In the film, though, Batman explicitly does want to kill Superman, the two of them are enemies from the get-go, and he has every reason to believe that Superman would kill him (especially considering what he previously did to General Zod), making you wonder why he would brazenly challenge Superman to a fist-fight in the open.
Suicide Squad keeps the classic lineup of the original comic book largely intact, even though it makes very little in-universe sense in the film continuity. In most DC Comics continuities, the Suicide Squad is just a team of covert operatives formed to carry out morally ambiguous missions for the US government, which is why it includes a mixture of both metahumans (like Killer Croc, Diablo, and the Enchantress) and ordinary people with special skills (like Deadshot, Harley Quinn, Captain Boomerang, and Slipknot). After all: you don't need superpowers to be a decent soldier. In the movie, however, the Squad is explicitly formed by the government to serve as a countermeasure against superheroes potentially going rogue and becoming a threat to humanity—making it extremely questionable that the government would recruit costumed crooks without any superpowers to join the team. Case in point: how is a mentally unbalanced woman with a baseball bat supposed to go toe-to-toe with someone like Superman? And if the whole purpose of the Squad is to protect the American public in case superheroes prove to be untrustworthy, why is it almost entirely made up of criminals and psychopaths who've never been trustworthy? Relatedly: in most prior continuities, the Squad aren't formed until well after superhero teams like the Justice League and the Teen Titans have already been established for years, making it a bit more understandable that the government would want to have an "alternative" costumed group on their side to perform missions that conventional superheroes would refuse to do. But in the DCEU, the Squad is apparently the world's first team of metahumans, being formed before even the Justice League—making it very strange that the idea of recruiting a motley crew of costumed weirdos would even occur to anyone in the government.
Zack Snyder's Justice League notably goes out of its way to incorporate Darkseid into the story to address complaints about him being kept offscreen in the original version of the film. As a result, he's the one shown leading the Apokoliptian invasion of Earth in the flashback sequence instead of Steppenwolf. But after encountering Steppenwolf later in the film for the first time, Wonder Woman (the one who tells the rest of the League about the first Apokoliptian invasion) still inexplicably knows who he is—even though she's never mentioned him before that point, and there's no indication that he's ever been to Earth before.
The TV adaptation skips the subplot about what happened to the previous postmasters by revealing they were killed by Reacher Gilt's banshee assassin. However, the only reason the Post Office is standing in the book is that Gilt doesn't see it as a threat; as soon as he does, he doesn't mess around killing postmasters, he burns the place to the ground. In addition, a rearrangement of scenes means that TV Gilt has to kill Horsefry personally, when the man is visiting his office, rather than employing the hard-to-track Mr Gryle to swoop down and kill him in his own home. Despite the TV version retaining Ankh-Morpork's capable and determined Watch (and its bloodhound-like werewolf), this crime apparently goes unsolved.
The TV adaptation has Angua twice arrest Moist for breaking his parole by leaving the city, but for some reason there was no problem earlier when he took a horse to Sto Lat. (In the book, it's made clear he can leave the city as long as he's on Post Office business, which applies all three times.) It's also not clear why this is even Angua's job; Mr Pump is still his parole officer, and collects him when he actually tries to escape.
Dracula (1931) keeps the plot point of Dracula biting and turning Lucy, but after there's mention of her reappearing as the 'Bloofer Lady', the film abandons this plot point and the protagonists are focused on stopping Dracula and saving Mina. Especially egregious since her death scene from the book was scripted, and the Spanish-language version, which used the same sets and costumes and shot at night when the English-language production had finished, does resolve this plot point.
The film opens with a prologue explaining that (just like in the manga) King Piccolo originally tried to conquer the world 2,000 years in the past before being defeated and imprisoned. Unlike in the manga, however, he's depicted as having a giant ape-like minion called "Ōzaru". This ultimately leads to a Plot Twist where it's revealed that Goku was actually Ōzaru all along—implying that he's actually over 2,000 years old, and somehow lost his memory. But if Goku is over 2,000 years old, then why does he appear to be just eighteen years old? And why doesn't he remember trying to conquer the world? And if he's been on Earth for over 2,000 years, then how could his adoptive grandfather Gohan have "raised" him? It's all the more inexplicable since the movie begins with him celebrating his eighteenth birthday, implying that he's aged perfectly normally over the course of 18 years. In the manga, Goku (like all Saiyans) does initially have the ability to transform into a giant monstrous ape under certain circumstances, and he does eventually discover that he's a member of a malevolent race of alien warriors who sent him to Earth on a mission to conquer the planet—but he has no association with King Piccolo, he isn't unusually old, and it's explained that he doesn't remember his origins due to a head injury suffered when his spaceship crash-landed on Earth.
Many viewers and critics found it very hard to believe that Goku would use the Dragon Balls to resurrect Master Roshi (whom he's only known for a few days at that point) at the end of the movie without even considering using them to resurrect Gohan (the man who raised him). The source material dealt with this: shortly before Goku gets his first chance to use the Dragon Balls during the Uranai Baba Saga, he briefly reunites with Gohan after Baba uses her magic to temporarily bring him Back from the Dead; during their brief reunion, Gohan makes it clear that he has no wish to be resurrected, having lived a long and fulfilling life already. But since this moment is nowhere in the film, the possibility of Goku bringing back his grandfather is just never addressed. It also helps that Bora (not Master Roshi) is the first character brought back via Dragon Balls in the manga. Bora was a relatively young man who was murdered in the prime of his life, leaving behind an orphaned young son who wasn't old enough to take care of himself—and Goku promised his son that he would use the Dragon Balls to give him back his father. With that in mind, it's much more understandable that Goku would choose to bring him back rather than bringing back his grandfather, who was already an elderly man in his twilight years when he died.
Since the film's version of Piccolo is something of a Composite Character with Emperor Pilaf, Mai is depicted as his henchwoman and personal assassin (she was Pilaf's henchwoman in the manga). But Pilaf was the wealthy ruler of a vast kingdom, so it made sense that he had a professional assassin in his employ. By contrast, Piccolo is a demon who spends 2,000 years magically imprisoned prior to the start of the movie, presumably leaving him with no knowledge of human culture or society in the intervening two millennia when he got out—so how did he manage to hire a hitwoman? Moreover: just like in the manga, he has the ability to spawn his own minions—so why does he need a personal assassin in the first place?
In Flowers in the Attic after the husband dies, Corrine has to go back to her rich family and hope for an inheritance or else her children will have no money. In the book, Chris and Cathy are fourteen and twelve respectively, but the movie ages them up to at least sixteen or seventeen, so them finding jobs and/or taking care of the twins while living in their old house seems a much simpler solution than them staying in the attic for months while Corrine tries to reconcile with her grandfather. Also, as they're older, them being afraid of their grandmother is a little less believable - Chris would easily be able to overpower her.
The adaptation of The Foreigner (2017) essentially kept the same backstory from the novel, but moved the main action from the early 1990s to its 2017 release date. Although this works surprisingly well overall, Quan's daughter Fan is still portrayed as a twentysomething student, as she was in the novel. Since Fan was apparently still born in the early 1970s, she should be in her mid-forties at the time the film is set.
Full Circle completely leaves out the connection between its main character and antagonist, which was detailed in the original book.
In Infernal Affairs, only Superintendent Wong knows the identity of the undercover cop. When he's murdered, the cop has no one in the police department to turn to. In The Departed, both Captain Queenan and his assistant Sergeant Dignam know who the undercover cop is. When Queenan is murdered, the cop acts like he has no one to turn to, but Dignam is simply away on suspension. Why no one bothers to look him up is never explained. Dignam's sudden reappearance at the end is treated as a surprise, but fans of the original would be waiting for that dangling thread to resolve for half the film.
Minor one in Into the Woods. Rapunzel is actually the Baker's long lost sister, having been taken by the witch when he was a toddler. The Baker never finds this out in the stage show, and it's the same case in the film. The Plot Hole comes from the fact that the Narrator is a separate character in the stage show. For convenience purposes the Baker also serves as the Narrator in the film. And the film ends with the Baker narrating the story to his newborn son. But since he never finds out Rapunzel is his sister, it raises the question of how he knows this in narration.note Though there is a small possibility since Rapunzel survives in the film, that she and the Baker eventually do reconcile some time after the events of the story - as the narration says a lot of things the Baker wasn't witness to, so it could be assumed that the narration we hear is him telling the story much later after getting the rest of the information.
On Her Majesty's Secret Service is one of the more faithful adaptations of a James Bond novel to film—which, ironically, leads to problems. In the previous novels, Bond had never met Ernst Stavro Blofeld directly, so naturally they did not recognize each other on sight in the OHMSS book. But in the previous Bond movie, Bond and Blofeld had met face-to-face. However, they still do not recognize each other in the OHMSS movie, because they didn't recognize each other in the book! The fan theory is that Bond's plastic surgery to appear more Japanese in the movie You Only Live Twice meant Blofeld didn't recognise him.
Additionally, the films made SPECTRE the antagonist of all but one of the previous Connery films, whereas in the novels they'd only previously been in Thunderball. They even instigated a revenge plot against Bond in From Russia with Love. This makes it even more unlikely that Blofeld had never seen a picture of Bond.
Overlapping with Adaptation Explanation Extrication, the Earth Kingdom prison camp. In the series, the Earth Kingdom prisoners are trapped on a rig out at sea, and need Katara's help because they have no obvious earth to bend. In the film, the Earth Kingdom prisoners are in a garden-variety landbound prison camp, and need Aang's help because it apparently just hasn't occurred to them that the ground here also counts as earth. While both versions explain that the Earthbenders had their spirits broken and no longer wanted any trouble, the film fails to give a reason for how they lost their spirit, as they always had access to their greatest weapon while their animated counterparts were handicapped until the heroes brought them a supply of coal to use.
The film adds the idea that Firebenders can only manipulate pre-existing sources of fire, unlike in the show, where Firebenders create their own fire from the heat in the air. This raises the question of why all other bending types (or really, anyone with a bucket of dirt or water) aren't able to easily disarm them by simply putting out their fire before or during a fight. And during the Siege of the Northern Water Tribe, the tribe's leaders even tell people to put out their torches, and yet they're still burning afterward.
In the show, Zhao is able to piece together that Zuko is the Blue Spirit after discovering the Blue Spirit's dual broadswords on Zuko's ship. This scene is cut from the movie, meaning the audiences has no explanation for how Zhao realized Zuko is the Blue Spirit.
There's also the matter of how Quatermain figures out that "M" is Professor James Moriarty in the climax, which is never explained. The movie makes a big deal about Moriartytaking on multiple identities, including "M" and "The Fantom", and the League personally meets with "M" in London before he sends them off on their mission—implying that he isn't someone they would recognize. In the comic book, "M" is just Moriarty's callsign in British Intelligence, and he stays hidden behind the scenes for most of the story before choosing to reveal himself.
The movies leave numerous questions about Aragorn to people who haven't read the books. If everyone knows him to be the rightful heir of Isildur and King of Gondor, why isn't he already? Why is Aragorn a 'Ranger from the North' if his homeland is Gondor? In the book, Aragorn's ancestry is not nearly so well known, his ancestors are not from Gondor but a sister kingdom to the north, and he has to go to considerable lengths to prove he's the rightful heir to the southern or rather reunited throne, though even the book left most of this backstory to the appendices. The movies do attempt to at least clarify why he hasn't taken the throne yet by playing up his concerns over ruling due to Isildur's actions leaving him uncertain if he isn't going to make mistakes, but other details don't get the same explanation.
The films include two scenes where Frodo clearly displays to Sauron's forces that he has the Ring—first when he comes face to eye with Sauron after putting on the Ring in Bree, and later when one of the Ringwraiths (who have a powerful psychic connection to Sauron) sees him with the Ring at Osgiliath. This can leave some viewers wondering why Sauron never seems to know where the Ring is, and why he puts so much effort into attacking Minas Tirith instead of looking for Frodo. The answer is that neither one of those scenes happens in the book: it's made clear that Sauron is never entirely certain who has the Ring, but his suspicion is that it's Aragorn (which is also why Aragorn is able to goad him into attacking his forces at the Black Gate). It's also explicitly stated that Sauron would never consider the possibility that someone might try to destroy the Ring instead of taking it for themself and trying to dethrone him, which also explains why Mount Doom is relatively unguarded: it never occurs to Sauron that someone might go there.
The above also causes a plot hole with The Hobbit trilogy. If Sauron and the Ring Wraiths can sense/see Frodo when he has the Ring on all the way in Bree, why can't they see Bilbo putting on the ring when he's in the Misty mountains or Mirkwood, comparatively right next door to their fortress of Dol Guldur.
In The Two Towers, the pretext of the Battle of Helm's Deep is that Théoden has decided to have his people take refuge in the fortress and "outlast" Saruman through siege. This doesn't make a lot of sense if one looks at a map; Helm's Deep is closer to Isengard, and it seems to have far less in the way of workable farmland to feed the refugees, and it's in the Westfold, which is already under assault. Why not just pull them back to some other fortress? And how can he fit a significant fraction of the population of Rohan (by all appearances, a pretty sizeable kingdom) into one relatively small fortress and some caves? In the books, Théoden's force at Helm's Deep was all soldiers, and his plan was initially to meet up with Erkenbrand, the leader of his forces at the Westfold (whose role is merged with Éomer) to take on the Uruk-Hai, while Éowyn led the remainder of Edoras to take refuge in the southeast. However, when Erkenbrand's forces were attacked and scattered, forcing Gandalf to head off and help reform them, he decided to move to Helm's Deep so that his army could have a base to defend the Westfold from. The film's change makes the threat a lot more immediate by putting the lives of countless civilians on the line (this is true in the books as well, but they consist only of those Westfolders who used the fortress for safety), but it also means that Théoden's plan to defend his people is apparently to lead them right into striking distance of the enemy.
In The Return of the King movie, Aragorn, Legolas and Gimli somehow sail a ship up the Anduin to Minas Tirith all by themselves — never mind that none of them have ever sailed a ship before (as lampshaded in DM of the Rings), and they'd need a larger crew anyway. Also, somehow the entire ghost army fits on that one ship while the rest are left behind. In the book, they also had thirty-something Rangers with them, plus thousands of soldiers from Lebennin who were free to come to Minas Tirith as reinforcements after the ghosts took care of the Corsairs of Umbar.
People who only saw the films frequently ask why Elrond didn't just take the Ring from Isildur and destroy it himself. The reason is that the whole "DESTROY IT!" scene just plain doesn't happen that way in the books. Isildur did take the Ring as a battle trophy against the advice of the Elves (Elrond included), but it's suggested that no one knew that it was imbued with evil, or that it was keeping Sauron alive. The moment referred to in the books also would have taken place on the battlefield where Sauron and his forces were destroyed, not at the Cracks of Doom (though they were "near at hand"), so it's unlikely that Isildur briefly considered throwing the Ring into Mount Doom before backing out at the last second. Another possible Hand Wave is that Elrond was afraid of taking the Ring himself, since he would have been even more likely to be corrupted than Isildur: the books explain that taking the Ring by force makes Sauron's power even stronger, and that the influence of the Ring is proportional to the power of its wielder—meaning that it has more effect on Elves than humans. Taking the Ring from Isildur (or just throwing Isildur into the flames) also likely would have sparked a war between humans and Elves.
"Why didn't they just use the Eagles to fly to Mordor?" While there are several reasons why this wouldn't have worked, most of which are true in both continuities (the Eagles might have been tempted to take the Ring for themselves, Sauron's forces could have killed them, they aren't bound to obey mortals anyway, etc.), part of the issue stems from the fact that the Eagles are portrayed slightly differently in the films. For one thing: they're shown to be much more powerful than they were in the books, creating the impression that they're practically undefeatable. While the Eagles do help the heroes turn the tide at the Battle of the Morannon in both versions, it took a massive host to do it in the books; in the movies, it just takes a handful of them. For another thing: in the books, it's made clear that the heroes have no way of contacting the Eagles, so they can't just ask favors of them whenever they might come in handy; in the movies, this clearly isn't the case. While Gwaihir (the lord of the Eagles) does rescue Gandalf from Isengard in both the books and the movies, he was only able to do so in the books because he happened to be traveling to Isengard to deliver a message; in the movie, Gandalf magically summons him by charging a small moth with contacting him. This left many viewers wondering why he doesn't use his magic to call the Eagles more often, since he can apparently summon them whenever he wants.
In the books, the first act of The Fellowship of the Ring includes a lengthy section where Gandalf explains the entire history of the One Ring to Frodo, including how Gollum got it. In this section, he also takes the time to fully explain Gollum's backstory (i.e. he's actually a hobbit named Sméagol who fled to the Misty Mountains after the Ring drove him to murder his cousin Déagol in a jealous rage). To improve the pacing, the film trims most of this section, including Gollum's backstory—yet Frodo still inexplicably knows Gollum's real name when he runs into him in the next movie. It's possible that Gandalf told him offscreen at some point.
A few relatively minor ones crop up in The Martian:
Firstly, it's never really explained why Watney never tries to patch up the Ares 3 mission habitat's communications antenna. In the book it's stated that the large microwave radio transceiver dish he needs for direct communications with Mission Control (the large object that was ripped away by the wind and clobbered him in the opening scene of the film) could be anywhere within several kilometres and is probably under two feet of sand anyway, but in the film, the dish is very clearly shown in in the background of the shot when Mark wakes up.
Another also minor one surrounding the "Mark Watney: Space Pirate" line. In the book, Pathfinder is fried by a poorly-placed drill, cutting off Mark's ability to talk to earth before he is officially given permission to commandeer the Ares IV MAV. In the film, the entire sub-plot is left out, and we even see Pathfinder being loaded on to the rover for the journey to Schiaparelli crater, thus raising questions about why he couldn't be given permission.
Less a plot-hole and more a weird visual problem. In the film, Watney is show cutting a hole in the roof of the rover and added some sort of bubble. This is given no explanation or purpose, especially seeing how much screen time is devoted to the montage of it happening. In the book, the rovers are much larger, have their own airlock, and there's two of them. The dome bubble is added to the second rover to accommodate the life support equipment.
The Avengers (2012): The film might leave some viewers wondering why Clint Barton and Natasha Romanoff become full-fledged Avengers so easily, since both of them are officially just garden-variety SHIELD agents with only a bit more skill than the average Redshirt, and neither has any superpowers or particular skill with gadgetry. In the comics, they weren't founding members of the Avengers; their spots on the team were occupied by Hank Pym and his girlfriend Janet Van Dyne, who actually did have powers and specialized gadgets. note Hank and Janet were originally going to be in the movie, but were Adapted Out after the planned Ant-Man film (which was going to introduce them) got stuck in Development Hell; director Edgar Wright also got really attached to the project, and requested that the studio leave the characters out of The Avengers so that he could introduce them how he wanted Clint and Natasha didn't join the team until some time later, and they didn't start out as SHIELD agents; they were a thief/vigilante and a Russian spy who had many run-ins with the Avengers before undergoing Heel Face Turns, and Tony Stark personally invited them to join the team after they redeemed themselves. Another part of the problem is also Power Creep, Power Seep, as well as Adaptational Wimp and Adaptational Badass being employed. When the Avengers formed, many of them were yet to undergo significant power creep, so Hulk and Thor, while power-houses, were still only about as strong as most other Super-Strength characters, Iron Man's armour had a number of weaknesses, and Captain America's abilities were within the realms of a Badass Normal. Thus, the idea of two other Badass Normal heroes, particularly ones who had Charles Atlas Superpower skills and used such specialised gadgetry that made them a match for the Avengersnote indeed, when Hawkeye first met Iron Man, he kicked his ass thanks to the sheer range of his Trick Arrow arsenal, and Iron Man only "won" the fight because Hawkeye had accidentally injured Black Widow and chose to flee for her safety rather than continue the fight, joining their ranks wasn't that ridiculous. The MCU, however, scaled Iron Man, Captain America, Thor, and Hulk closer to their power levels in later comics, while conversely, it scaled the abilities of Black Widow and Hawkeye down, even though they had both seen a similar power creep as the othersnote since their first appearances, Hawkeye has became a Walking Arsenal and One-Man Army who has mastered any weapon and also has such iconic accessories as his Sky-Cycle, while Black Widow has been retconned into being a Super-Soldier much like Captain America, and is regarded as one of the most dangerous people on the planet. The result leads to such a huge power gap between them that their inclusion seems all the more odd.
While not a full-blown plot hole, Adrian Toomes' backstory in Spider-Man: Homecoming apparently has Tony Stark act like an underhanded businessman by running his cleanup crew out of business and never compensating them, but this is never acknowledged as being out-of-character for Stark, nor is it called out as wrong by anyone other than Toomes himself. In most continuities, Toomes is driven to villainy by the corporate greed of a business partner portrayed as being just as villainous as Toomes himself (adaptations often give this role to Norman Osborn). The film also marks the official introduction of Damage Control (an organization from the comics responsible for cleaning up damage from superheroes' various battles), depicting them as the organization primarily responsible for the cleanup from the Chitauri invasion—but it makes no attempt to reconcile its existence with that of the various other groups that had previously been shown to be handling the cleanup job from the invasion (most notably Wilson Fisk and his contractors, as seen in Daredevil).
In The Maze Runner, while traveling across the scorch the Gladers are caught in the middle of a lightning storm, where the lightning appears to be actively chasing them, with several characters getting struck. It’s implied, and outright speculated In-Universe by Thomas, that the lighting is being artificially created by WICKED. Maze Runner: The Scorch Trials keeps this scene, but only having Minho being the one struck and removing Thomas’s theorizing. However, unlike in the book WCKD are no longer in control of the Gladers who have already escaped from them and don't have the level of technology required to artificially make or manipulate a storm like their book counterparts had, making it unclear how apparently naturally occurring lightning is able to chase someone.
In the "Who Am I" number, Valjean simply tells the judge who he is to clear the falsely-accused man's name, providing no more evidence than saying that Javert will recognize him (and given that Javert just spent the last scene saying he now believes that Valjean is not the convict he was looking for, it comes across as Javert having rather bad judgement). In the musical, the script specifies that Valjean proves his identity by showing the tattoo of "24601" branded on his chest (In the book, Valjean proves his identity by conversing with the three Toulon convicts who were brought to Champmathieu's trial to testify, telling them things that only someone who did prison time along with them would know; this version of the scene did make it into the 1998 film adaptation).
Another takes place when Thenardier and his gang try to rob Valjean's house. In the play, after Eponine gets rid of them, Cosette pretends she saw three mysterious men lurking outside which caused her to scream, thus causing Valjean to think Javert has found him. In the movie, Cosette has already gone to bed and thus Valjean only hears Eponine screaming and... somehow comes to the conclusion that this means that Javert is nearby.
Eponine still crossdresses in this version, but for unclear reasons as there are women openly staying on the barricades.
In this version, the Thénardiers (Éponine included) disappear from the story completely after Valjean adopts Cosette from them. This removes one of the main reasons for Marius to get close to Valjean (thwarting his kidnapping), as well as the failed burglary that motivates Valjean to move himself and Cosette to a different location, which was originally the main reason (along with Éponine's surreptitious urging) Marius chose to stay and fight in the barricades rather than run away with her. Instead, this version shows Marius being convinced by Enjolras to fight in the barricades so that he "can make love to [Cosette] as a free man". However, Gavroche (who is a Thénardier, and Éponine's brother) is still present for the Paris acts of the story, raising the question of how he got there when his siblings and parents apparently never did.
The above is related to how Javert ends up as a prisoner in the barricade; rather than going undercover and pretending to be a revolutionary before being outed by Gavroche, this Javert effectively takes Cosette as a hostage so he can lure out Valjean (in the book and most other versions, Cosette and Javert never meet), replacing the burglary scene, but is foiled by Marius, who manages to capture and bring him to the barricades.
Javert also shackles himself and jumps into the Seine in full view of Valjean, having waited for the latter to return to him after taking the wounded Marius to a safe place, after delivering a quick spiel about how he can't reconcile a former criminal being able to do the right thing while failing to obey the law. In the book, Javert never monologued about this to anyone (in the musical, only to himself), and he certainly didn't wait for Valjean to come back before offing himself; this was likely related to the decision to cut the story short for the film at this point, as the remaining scenes showing Marius's estrangement and reconciliation with Valjean, Marius and Cosette's wedding, and Valjean's eventual death and resting place would likely not flow very well considering the aforementioned Thénardier's disappearance. Had these scenes been included, another plot hole related to the previous bullet point would also crop up, as in the book Marius grows distant from Valjean because he believes he murdered Javert, whom Marius deeply respected.
In City of Bones, Simon was abducted by vampires because he'd been turned into a rat, and they mistook him for one of them. In The Mortal Instruments: City of Bones, they took him as a hostage because they wanted the Mortal Cup. The movie failed to give us any possible use Vampires could have for the Cup.
Unlike their counterparts from the play, Odin and Desi are not a married couple from the 16th century; they are 20th/21st century high school kids dating. Yet when Odin is tricked into thinking Desi's sleeping around, it never seems to occur to him to just break up with her rather than killing her. The movie attempts to hand wave it with him having a history of addiction, and slipping back into cocaine once he starts thinking she's cheating.
Emilia's counterpart Emily bizarrely doesn't intervene when Odin has accused Desi of misplacing the scarf he gave her, even when he's accusing her of cheating on him. In the play, it made sense why she would keep quiet, as she was just Desdemona's handmaiden and could fear speaking out of turn, and Iago was her husband, so she also couldn't speak against him. It makes it extremely odd why Emily doesn't just admit she took the scarf on Hugo's request when she can see how the misunderstanding is escalating.
The 1998 remake of The Parent Trap changes the nationality of one of the two twins, making her British instead of just being from Boston—but the plot is still kicked off by the twins coincidentally reuniting at Summer camp. Setting aside the unlikelihood of a British girl traveling halfway across the world just to attend Summer camp, British public school students begin Summer vacation considerably later than American students (usually in late July rather than early June), and Summer vacation lasts considerably shorter in the United Kingdom than it does in the United States (usually around six weeks rather than around three months). As a result, it's highly implausible that Annie and Hallie could have arrived at the camp and departed at exactly the same time, since it's said that Camp Walden lasts for eight weeks.
The short story turned short film Paul's Case has an example of this, although it's not so much a plot hole as a moment of characterization kept in when it didn't fit with the other changes. In the original story, Paul is portrayed in a way that makes it easy to assume he has mental problems. In the film he's turned much more sympathetic, and is shown to be a victim of circumstances, yet the film keeps in a scene where Paul creepily fantasizes about his father shooting him when he crawls through his basement window.
In the play version of Perfect Pie, Marie's reluctance at going swimming is because she's afraid of having a seizure while she's in the water. In the movie adaptation she doesn't have seizures, leaving her fear of going swimming inexplicable.
Romeo and Juliet (1968), the line about "a brace of kinsmen" being lost is still kept intact, even though Paris's death isn't included in the filmnote It was filmed but cut for pacing., and Lady Montague is Spared by the Adaptation — so the Montagues have only lost one kinsman. The Prince's line in the play refers to the fact that each of the three families has lost two kinsmen: Tybalt and Juliet for the Capulets, Romeo and his mother for the Montagues, and Mercutio and Paris for the Prince.
In Safe Haven, it's explicitly stated that it took a year of saving for Erin to have the money to escape from her abusive husband, along with having to plan out every detail such as waiting until he goes out of town, forwarding his calls to a cell phone, then staying in cheap motels and barely eating in order to get by. In the movie, she flees from his impulsively following an argument, yet has the money for a bus ticket and to rent and fix up a cottage. Even if one assumes that her neighbour loaned her some money, it's unlikely it was enough for all that.
The Seeker is very loosely based on the The Dark is Rising series written by Susan Cooper, specifically the second book. In the book, Thomas Stanton was the Stantons' first child who died soon after he was born. In the movie, however, he's Spared by the Adaptation and revealed to be Will's twin brother who was kidnapped by the Rider when they were babies. This raises the question of how the Rider didn't realize he'd kidnapped the wrong child or why he didn't kidnap them both just to be sure.
In the book of Sleeping with the Enemy the heroine has to live on oatmeal and beans for months after escaping her abusive husband. The film instead has Laura inexplicably affording a large and spacious house, complete with luxuries like brand name goods, despite having only a part-time library job before her escape and not working for ages after she does settle into town.
The 2002 Spider-Man film adaptation slightly changes the details of Uncle Ben's death to make Peter a more sympathetic character: instead of refusing to stop the thief who goes on to kill his uncle because he doesn't think it's his problem, Peter refuses to stop the thief to get back at a wrestling promoter who screws him out of his prize money for winning a wrestling match (he refuses to intervene when the promoter is robbed). But this raises the question of why the promoter would exploit a loophole to cheat Peter out of his prize money when he could presumably make a lot more money by signing Peter up as a new star attraction, since he just saw him take down a guy twice his size to the approval of a roaring crowd. This pretty starkly contrasts the comics, where Peter successfully becomes a television star after he initially gets his powers. The promoter is also clearly opening himself up to a lawsuit by refusing to hand over the prize money, since Peter is shown signing a written agreement before taking part in the match (sure, the Parkers are probably too poor to hire a lawyer, but the promoter can't possibly know that).
In Transformers comics, transformers with the ability to transform into biological animals (including humans) are known as "Pretenders", who are fitted with special external armor shells so that they can do this when normal bots can't. In Transformers: Revenge of The Fallen however, the decepticon "Alice"'s ability to disguise herself as Sam's classmate seems to come out of nowhere, especially considering the audience was explicitly shown how both mini-cons and normal bots scan their Alt-modes in the first film, and there is nothing to indicate they can do this on anything non-mechanical.
Troy: The film attempts a Demythification of The Iliad, telling the story of the Trojan War with no mythic or supernatural elements whatsoever. While most of the story works fine, the finale with the Trojan Horse stretches Willing Suspension of Disbelief quite a bit. Sure, everyone in the audience likely knows that the Trojans are going to take the horse with the Achaean army concealed inside, but more skeptical viewers might wonder just why they never think to wonder if it's a trap, or even inspect the horse before taking it into the city. Well, in most mythical accounts of the Trojan War, they did. The Trojan priest Laocoön pointed out that it was probably a trap...and was promptly strangled to death by a sea serpent sent by Athena, who was on the Achaeans' side. After that, they understandably got scared, and came to the conclusion that they'd risk the Gods' wrath if they refused to take it. In Troy, there are no sea serpents, and only Paris even questions the wisdom of taking a giant wooden horse into their city walls after the enemy Achaeans all mysteriously disappear.
In The Twilight Saga, it is mentioned in both the novels and the film adaptations that whenever the Volturi identify a vampire that they wish to recruit into their number, they will commonly find an excuse to eradicate the other members of the chosen vampire's original coven before offering the chosen vampire membership in their coven. The novel addresses the obvious question of why the chosen vampire would even consider accepting an offer of membership with the very group that just wiped out their previous coven by revealing that the Volturi have an unseen member named Chelsea whose special gift enables her to influence the bonds of loyalty in other vampires (both weakening a potential recruit's loyalty to their old coven and strengthening their loyalty to the Volturi). The film adaptations never mention Chelsea or even bring up the aforementioned question.
The film version of V for Vendettacuts the government's supercomputer Fate, likely because in modern day such computer systems are no longer dystopian sci-fi devices, but everyday reality. V having completely subverted the computer that controlled everything for Norsefire was a major plot point in the graphic novel, but without it, his ability to never show up on any of Norsefire's omnipresent surveillance becomes less believable. The film version of V is shown capable of subverting the Norsefire's surveillance in the film, but the details are left vague.
Virus: Day of Resurrection has a Race Against the Clock to turn off a nuclear defense network from firing. In both the novel and the film there are two such systems, one in the USA and one in Russia. While the USA mission arrives too late, the novel implies the Soviet team is successful, thus no missiles hit North America. The film makes no such mention of the Soviet team, and total nuclear winter occurs; this making the hero's long walk from Washington to South America nothing sort of an outright miracle as he arrives with nary a hint of radiation poisoning.
Watchmen: Since the film adaptation slightly changes the book's climax, it also gives a slightly different explanation for why Eddie Blake was murdered. In the book, it's laid out that he accidentally discovered the island laboratory where Adrian Veidt was conducting experiments to create his creature while returning from a mission in South America, initially mistaking the laboratory for a Sandinista base. The movie just says that he figured out Veidt's plan after being ordered to investigate him by the government, with no real explanation of how he figured it out (implying that the "World's Smartest Man" got outsmarted). But if Veidt was under investigation by the government, why didn't anyone from the government investigate him further after Blake's murder? And why didn't Blake bother to report the results of his investigation to anyone? Considering Blake was killed after being specifically ordered to investigate Veidt, you'd think that would make him a pretty obvious suspect in Blake's death.
Combining the roles of the two Good Witches (of the North and the South) creates the plot hole where Glinda doesn't tell Dorothy what the slippers do on their first meeting, which would have saved her a lot of trouble. Originally the Good Witch of the North (not Glinda) gave her the shoes, but only Glinda (the Good Witch of the South, whom Dorothy meets at the end) knew they could bring her home. In the film, Glinda defends her withholding of this crucial information by explaining"She wouldn't have believed me!" despite the fact that, being in a magical land with talking trees and animals, and being hunted by a witch who'd made it clear she wanted to kill her, Dorothy would have been willing to try anything.
The death of the Wicked Witch of the West was also brought about by one of these. In the book, she'd made Dorothy a slave in her castle while she thought up a way to get the silver shoes from her - the bucket of water was present simply for Dorothy to clean the floors with, and she doused the Witch with it in a fit of rage at having one of the shoes stolen. In the film, the water comes completely out of nowhere when Dorothy uses it, and it makes the Witch look foolish for choosing to set the Scarecrow on fire when her greatest weakness was right nearby to put it out.
in DM of the Rings), and they'd need a larger crew anyway. Also, somehow the entire ghost army fits on that one ship while the rest are left behind. In the book, they also had thirty-something Rangers with them, plus thousands of soldiers from Lebennin who were free to come to Minas Tirith as reinforcements after the ghosts took care of the Corsairs of Umbar.