The character of Pete, the largely silent and essentially background droog in A Clockwork Orange, played quite a pivotal role in the last chapter of Anthony Burgess's original novel. However, since Kubrick'sadaptation was based on a version of the book with the final chapter excised, Pete's role was rendered largely inconsequential.
A literal example. Isabelle Fuhrman had been cast in a small role in After Earth , but in the finished film, she is reduced to a split-second non-speaking appearance (when Kitai is told he is not being advanced).
The Chipettes only had a small role in Alvin and the Chipmunks: The Road Chip.
Commissioner Gordon (played by Pat Hingle) in the original Batman film series. He's the most competent non-costumed character in the first film, is barely in the second film, shows up in his pajamas in the third, and then is completely humiliated in the fourth (and yes, it was part of a major plot thread, but that's still no excuse).
Death, who's the book's narrator, only has a few voiceovers through the film of The Book Thief (the beginning, the end, and a few Time Skips).
The French played a substantial role in the Crimean War, contributing more troops than the British and taking part in all of the war's major battles. You wouldn't know it from The Charge of the Light Brigade, where they're barely mentioned.
Dan Murray, who played a large role in Clear and Present Danger and all Jack Ryan Sr. books after that, is killed in the Colombian Cartel attack on the FBI Director, when in the book, he wasn't even there!
Alfred has very little screen time in The Dark Knight Rises. Though he does at least make the most of what he has, providing his usual insight, wisdom, and poignancy.
Scottie had a somewhat larger role in the novel (she confronts Troy at the club, and has several moments of acting out by hurting herself) than in the film of The Descendants.
LAPD officer Sergeant Al Powell is a big part of Die Hard, but none of the other films take place in Los Angeles. The second film offers him a gratuitous cameo, and the rest leave him out all together. Possibly justified in that Al had a family and was working the beat again by the second movie, so he wouldn't have been able to join John for more adventures.
This also occurs in the third film, as a result of Doc, Galgo, the new Expendables, Trench, Drummer and Yang all taking part in the final battle. Hale is nearly killed during the second mission and incapacitated until the last scene, while Toll Road and several others get next-to-no dialogue for most of the film.
In the sixth installment of The Fast and the Furious series, Mia's role is downgraded so she can look after her and Brian's son. She only makes a few appearances early on and then isn't involved again until the climax when Owen Shawtakes her hostage.
Doctor Mindbender was more of an inversion. The character was never intended to have a name, and was only there as a plot device for The Doctor's path to darkness. After the fact, they realized he could easily be Mindbender and threw his name in for the fans.
Rico and Oliver were reduced to a few lines at the beginning of the Hannah Montana movie.
Laurie Strode (Jamie Lee Curtis) was the main character of Halloween, but only has about 10 minutes of screen time in the sequel, despite sharing top billing with Donald Pleasance. Leigh Brackett (Charles Cyphers) also only appears in two scenes, despite his larger role in the previous film. He still receives third billing. Likewise, Annie Brackett (Nancy Kyes)'s major role in the first film was reduced to a mere cameo in the second ( as a dead body). The rest of the franchise was filled with several cases of Sudden Sequel Death Syndrome.
Percy Weasley. He wasn't all that big a player in the books, usually being involved in the side-plots, but his estrangement from his family was a poignant reminder of what Dumbledore always said about Voldemort's gift for dividing loyalties. After the third movie, his only appearances consist of non-speaking cameos in Order of the Phoenix and Deathly Hallows Part 2. Unless you watch the backgrounds, you wouldn't even notice he's there and is apparently still going through his book plotline, albeit almost entirely off-screen.
Tonks sadly doesn't do much in any of the four films she appears in.
Up until Deathly Hallows, Charlie was mentioned a couple of times in the first film and Bill wasn't mentioned in the films at all. Bill and Charlie's only actual appearances in the first six films were in the photo of the Weasley family in Egypt, which was onscreen for about a second.
Mundungus Fletcher had a few minor roles in the books, but was completely ignored in the films until Deathly Hallows Part 1, when he was required for the plot. Resulted in a bit of a shoehorning. Kreacher likewise had his role downplayed greatly, and since his introduction, got barely a cameo in Deathly Hallows Part 1. Both were still little more than extras for much of the series anyway, but it's even more egregious in the films.
In the "Appendices", Dáin played a major role in the Battle of Azanulbizar; the Iron Hills Dwarves turned the tide of the battle, and Dáin himself killed Azog to avenge his father. Presumably Dáin's role was scaled back after the decision was made to keep Azog alive in the movie trilogy.
Arguably, Bilbo himself. The first two films center around his involvement in helping the Dwarves of Erebor reclaim the mountain from Smaug. Once Smaug is killed in Battle of the Five Armies, he gets a few scenes here and there, but much of the film is centered on the eponymous battle and Thorin's inner struggles.
Smaug in the third film. Justified in that he gets killed by Bard about twelve minutes into the film, and only reappears in flashback sequences.
While Amy was one of the main characters in Honey, I Shrunk the Kids, in the sequel Honey, I Blew Up the Kid she only appears at the very beginning before taking off for college. The reason was the film wasn't originally supposed to be a sequel to HISTK. When the movie became a success, it was quickly reworked into one, but the original treatment didn't have roles for either Nick or Amy to fit into. Although Nick ultimately managed to still get a decent part, there really wasn't any room for her.
Not that Cray has major role in the book, but the film reduces his appearance to a single scene.
While Blight never really was important to the story, his onscreen appearance in the film is only in the interviews, and later in a passing mention by Johanna.
Ceelia and Woof. Katniss never talks to them in the training center, nor are they mentioned when Haymitch introduces the tributes to them or the bloodbath, only being seen at the interviews and the tribute parade in the film.
Seeder is only in one scene in the film, and she doesn't inform Katniss about Rue's family.
Johanna only appears for a few seconds, having spent the movie being tortured in the Capitol off-screen. Fittingly, her part in the book wasn't really expanded on until the events that take place in the chapters associated with Part 2. Promotional material and videos seemed to indicate it was going to undergo Adaptation Expansion but it was ultimately kept just like in the books.
Finnick. Most of his character moments are cut or passed on to others (the "kiss you, kill you, or be you" line was originally his, not Effie's), and his big moment of plot relevance, when he tells the story of his own forced prostitution and Snow's rise to power, is massively downplayed. While it was a huge character-defining moment in the book, causing Katniss to completely rethink her opinion of Finnick and was given the full focus of the narrative, in the movie, it's going on in the background as Katniss and the camera focus on the rebels' mission.
Effie Trinket, while having substantial roles in the previous films, appears mainly at the denouement in this film and also has a brief cameo during Finnick and Annie's wedding note Effie is more of a supporting character in the books and doesn't sympathize with Katniss and Peeta that much. However, the filmmakers upgraded her to a main character in the films, hence why her sparse appearance in this is quite jarring.
Johanna as well, due to a large portion involving her and Katniss training getting cut, leaving little else for her to do.
To many fans' chagrin, this occurred to Penny and Brain in Inspector Gadget. Instead of being in the forefront of the film to help solve to crimes at hand like they were in the cartoon series, both were more or less seen in the background and barely given any lines while the titular inspector and a new character in the form of Gadget's Romantic Interest, Brenda, are the heroes of the film and get most of the dialogue.
The Mysterious Man (the Baker's father) played a large part in Act One of Into the Woods, but only appears twice in the movie.
Most of the animal characters in The Jungle Book, while the movie focus more on Mowgli's interaction with other humans.
Jeri Ryan originally had a supporting role in The Kid as one of Russ' clients, and there would have been a minor Romantic Plot Tumor later in the film involving her character, where she starts hitting on Russ, and making Amy jealous. In the final cut however, Ryan's role was obliterated completely, and now she only has a small cameo on Russ' television being interviewed.
The Last Airbender naturally has this by virtue of trying to condense twenty episodes into two hours.
Momo shows up long enough to be introduced, then occasionally shows up in the background a couple times. You could be forgiven for not believing him to have followed Aang after the introduction.
Appa was also demoted. He doesn't get a lot of screen time and is more of a mode of transportation than an actual character.
Arguably, Katara and Sokka. Neither of them get many scenes in the spotlight, nor do anything of much importance, especially when compared to their TV show counterparts. It doesn't help that many of Katara's strong scenes are either given to Aang or cut entirely. At least Sokka gets his girlfriend.
Haru and Tyro... ahem, Earthbending Boy and his father.
Jet is the small boy Zuko calls over to regale the story of the banished prince.
There's also Avatar Roku, who was a major player in the Avatar's quest in the show. In the movie, with the exception of a brief mention, he's completely removed and his mentor role to Aang is handled by a dragon...for some reason.
The 1929 film of The Letter starts off with some establishing scenes in which Hammond, Leslie's lover, receives the letter and goes to Leslie's house. He breaks up with her, and she shoots him. The 1940 film deletes these scenes and opens with Leslie emptying a revolver into Hammond. In this version the actor playing Hammond does not have any dialogue.
Hakan and the alcoholics in Let the Right One In have significantly reduced roles in the film adaptation. They are removed entirely from the American version.
A big casualty of this was Éomer, who was built up to be almost a Sixth Ranger to the trio of Aragorn, Legolas and Gimli in the book of The Two Towers. He was offscreen for much of The Two Towers movie as his role was merged with a minor commander who leads The Cavalry rescue at the fortress of Helm's Deep. Conversely, his sister Éowyn takes the almost-Sixth Ranger role since she also goes to Helm's Deep instead of leading civilians to another fortress. Their uncle King Théoden also takes his memorable lines and moments in The Two Towers and The Return of the King.
Also, Imrahil. In the books he's an important Gondorian commander and is the Acting Steward of Gondor while Faramir is healing. In the films he's shown a couple of times and it's not really made clear who he is.
Tim and Lex, now much older, only get cameos and are not mentioned again in The Lost World: Jurassic Park. The Velociraptors also get presented as dangerous obstacles as opposed to main antagonists like in the previous film.
In Maleficent, the three fairies—major characters of the original and part of the driving force of the plot—are reduced to about four or five scenes, all of which involve them being incompetent. They don't even get to soften the curse—Maleficent does that herself as a cruel Hope Spot.
Prince Phillip suffers this as well. In the original, he was a Badass Prince who took up the entire second half of the movie. In this film, he gets two scenes and has none of his badassery in either of them.
A number of important supporting characters from the previous films receive much less screentime in The Avengers.
Gwyneth Paltrow reprises her role from Iron Man, but in a minor capacity. Robert Downey Jr. asked for her to be included as a way of exploring the Potts/Stark relationship that was established at the end of Iron Man 2. Whedon agreed, because "you should always, given the opportunity, put a Gwyneth on-screen."
Dr. Selvig also returns from Thor, in a role that's more plot-important but doesn't necessarily get any more screentime.
Originally Maria Hill was supposed to be narrating the film. However, the scenes of her doing so got cut out.
Hogun the Grim makes a brief appearance early in Thor: The Dark World, having remained in his home realm to help rebuild it after the Marauders' attack; has another appearance, no more than a reaction shot, during the portal-hopping battle of the finale.
Hogun and the rest of the Warriors Three (Fandral and Volstagg) fare even worse in Thor: Ragnarok, getting killed in the first act, and with Fandral not even having any lines.
Happens to a lot of characters in Avengers: Infinity War. Both Heimdall and Loki only show up for a single scene before being killed off, while Nick Fury and Maria Hill only appear in The Stinger.
Peter's late Uncle Ben is never shown or even mentioned by name in the movies, with his role as Peter's father figure usurped by Tony Stark. The only evidence of his existence in the MCU is his initials on Peter's suitcase in Spider-Man: Far From Home, which gets destroyed with it being Played for Laughs despite it being apparently all he has to remember him by.
In an in-universe example, this happens to a character in Mrs. Doubtfire. Early in the movie, Mr. Sprinkles is the star of a children's show. At the end of the movie, he's replaced by Mrs. Doubtfire and is demoted to Mr. Mailman, a minor character.
Gus, the security guard's role as a Urban Explorer in Paper Towns is cut from the film adaptation leaving his role in the film to just a quick scene.
Done purposefully by the filmmakers and fandom of the Police Story/Supercop movies (combinations of Sequel First and Market-Based Title confuse the nomenclature.) Jackie Chan was the original star but one sequel (called Supercop in North America) featured Michelle Yeoh as a supporting character. She was so popular that the next movie (Supercop 2 in North America) featured her as the star, with Chan's character appearing only in a humorous cameo.
In the film of Queen of the Damned, Armand has two lines in total, and isn't even named as himself except by Word of God, though in the book he was a major player. Much of this is probably because Daniel Molloy was Adapted Out, and Armand's plot mostly revolved around Daniel.
Sandy West gets a sizeable character introduction but then does hardly anything else in The Runaways. This was enforced with Lita Ford, who refused to sign over her life story rights to the filmmakers.
In Scott Pilgrim vs. The World, Kim Pine, compared to her more involved role in the books (mostly because her backstory has been moved to the [adult swim]Animated Adaptation). Envy Adams gets quite a bit cut out as well, since her fight with Ramona is cut and is compacted into Ramona's fight with Roxy Richter. She is completely absent in the climax and her role is merged with Ramona's. Richter herself gets quite a bit cut out; she almost got a complete axing when Edgar Wright considered depositing Envy into her role as Ramona's 4th ex. Nega-Scott gets the axe from playing a pivotal role in the books to being reduced to a mere punchline in the movie. Lynette Guycott although having a minor but pivotal role gets barely minutes of screen time, and her punching the highlights out of Knives' hair was designated to Todd. Finally the Twins are almost cut out entirely, as they have zero lines (their actors don't speak English), zero backstory, and probably the least screen-time of any of the exes, only seemingly being in the movie because they are exes number 5 and 6 respectively.
In Serenity the characters of Book and Inara are set up as not living on the ship anymore. Shepherd Book is an odd example as he's only in two scenes in the entire movie (the second of which kills him off), less than any of the other main characters from the series. However, they're both really good scenes that play a major part in shaping Mal's own story arc as well as shedding some light on the film's villain, so despite his limited screentime he ends up being one of the more important characters.
Inspector Lestrade gets hit by this in Sherlock Holmes: A Game of Shadows. He may not have been one of the most central characters in the first, but he still had a decent amount of scenes and relevance to the plot. In the second movie, he is entirely left out, only briefly appearing at the end with few lines. His sergeant gets about the same amount of screentime, though he had a number of scenes in the original film as well. This is partly justified due to the Sequel Goes Foreign and most of the story took place outside of England, so Scotland Yard and its members won't be playing a large role until the plot briefly returns to it in the climax. A straighter example would be Irene Adler, who's actually one of the main characters in the first film and played a large role in the plot. She was killed minutesinto the sequel by Moriarty to demonstrate that the stakes are higher.
Almost all of Rosanna Arquette's scenes in Silverado now reside on the Columbia cuttingroom floor thus failing to explain how she goes from Emmitt to Paden in the course of the movie.
Extra might be going a little far, but Brom's role as Ichabod's rival is massively downplayed in Sleepy Hollow (1999). He's only in a handful of scenes, not really a threat to Ichabod and Katrina, and dies halfway through.
In "Stand by Me," Gordie narrates, "As time went on, we saw less and less of Teddy and Vern, until eventually, they became just two more faces in the halls. It happens sometimes: friends come in and out of your life like busboys in a restaurant."
None of Betty Brant's characterizations from the comics made it into the trilogy with the exception of being Peter's potential love interest, and even that isn't as prominent compared to the source material.
Gwen Stacy, from Spider-Man 3, is nowhere near as prominent as her comic counterpart. Her role was originally written to just be a random woman before Meddling Executives demanded Gwen be included in the movie.
Uhura, for most of Star Trek III: The Search for Spock. Mind you, her big scene in the transporter room is pretty awesome, but there is literally no reason for it ending with her being left behind other than that they didn't need her character for the rest of the film. The previous film, when everyone beams from Regula I to the caves inside Regula while leaving no one behind, shows that transporters can be operated on a time delay. This very film later also shows this, as none of the Enterprise crew remain behind when they beam off (while simultaneously beaming the Klingons aboard) before Enterprise's self-destruct. So there is no reason Uhura couldn't have put a short time delay on the transporter and joined everyone else on their mission to Genesis. (Fortunately, The Bus Comes Back just before the end of this film, so that she can be along for the next one.) The film's novelization gives Uhura a little more to do, as she scrambles Starfleet's communication channels during the Enterprise theft, and then joins Sarek in convincing the Vulcan government to pre-emptively grant Kirk and crew asylum there, instead of just handing them over to Starfleet authorities when they arrive.
She was intended for a major role in The Undiscovered Country, but between casting difficulties and objections by Gene Roddenberry over an established character becoming a traitor, her name was simply used as a placeholder for Kim Catrall's character, Valeris.
In The Undiscovered Country, Sulu is the captain of another Star Ship, and, while he is shown in this position a few times during the movie, filmed seperately from everyone else, he has no part in the story until the last 10 minutes, when the Excelsior comes to the rescue. He is only briefly in the same room as the rest of the cast, and even then it is doubtful if he was filmed alongside them.
Deanna Troi and Beverly Crusher in Star Trek: Generations. More so in Crusher's case, as she barely did anything in the movie, while Troi's role was proportionately about as large as she got in most TNG episodes.
Pretty much everyone in Star Trek: Nemesis except Picard and Data, but particularly egregious for Geordi, Dr. Crusher and Worf. All three do get additional scenes in the novelization, though. Even Riker, Picard's first officer, has much less of an onscreen presence than Data. That could be because Jonathan Frakes was so heavily involved behind the scenes of the movies, directing two of them.
Jar Jar Binks. Clearly set up in Phantom Menace as a Chewbacca for the prequels, he gets only a cursory nod in the sequel and a silent appearance in a group shot in the third. This was no doubt a result of fan backlash against the character.
In the original cut of A New Hope, Biggs Darklighter (this◊ X-wing pilot) had a much more prominent role. He's actually Luke's best friend from Tatooine who left to join the Imperial Navy, but the scenes where we learn this were deleted. In one scene, Luke meets him while on shore leave and he confesses that he's defecting to the Rebellion. In another, he and Luke get an emotional reunion before the attack on the Death Star, which makes his death in the battle a lot more tragic. The special edition restored his reunion scene with Luke, but left out the early scenes where we learn who he is.
Early versions of Return of the Jedi had a much larger part for the Death Star's commander, Moff Jerjerrod. In the shooting script, Jerjerrod is a high-ranking technocrat, taking orders directly from The Emperor behind Darth Vader's back. Jerjerrod butts heads with Vader over Luke Skywalker's capture and even has the guts to deny Vader passage into Emperor's Throne Room, leading Vader to strangle him near to death. Late, he reluctantly accepts orders from The Emperor to fire the Death Star on the Endor moon despite many Imperials still present there and even gives the order shortly before the station is destroyed. In the final cut, his biggest scene is greeting Vader's shuttle in the opening.
C-3PO gets next to no scenes of importance in Revenge of the Sith, which he lampshades by stating how helpless he feels regarding everything going on around him.
Rose Tico, introduced in The Last Jedi as a fairly prominent character and even Love Interest of Finn, is reduced to a background character at best in The Rise of Skywalker and gets maybe three lines at most, zero relevance in the plot, one brief scene during the final firefight, and absolutely no mention whatsoever of her and Finn's romantic interest in one another. This was in response to her divisive at best character as well as the entire casino subplot being heavily lambasted for basically adding 30 pointless minutes of "prequel-like" terrible CGI to the movie.
The fate of Mr. Utterson from The Strange Case of Dr. Jekyll and Mr. Hyde, due to most every adaptation centering on Jekyll from the start rather that Utterson investigating a mystery, as the novel did. In the 1920 film he pops up towards the end as one of Jekyll's friends, in the 1931 film he is an extra, and in the 1941 film he's completely omitted.
Cammy, T. Hawk, and Captain Sawada have very little screen time in Street Fighter. More glaringly, Ryu and Ken go from co-protagonists to Those Two Guys.
Jerry Killian is a very minor character in the book of Striptease, but his screen time in the movie is still reduced. The same happens to Joyce Mizner, who is barely there before she bites it (although Joyce is really only there as the fiancée of the man Dilbeck attacks).
Lois Lane in Superman III shows up in the beginning, says she's going to Bermuda and disappears for most of the movie. Then she comes back before the movie's over as if nothing happened! This was largely done in retaliation after Margot Kidder criticized the producers for their decision to dismiss director Richard Donner from the franchise. It's a testament to how iconic the Superman mythos is in general, and Lois Lane in particular, that it wasn't worse.
Not to the extent that she was in Superman III, but Lois Lane still spends much of Superman IV: The Quest for Peace sidelined in favor of Lacy. However, this time round she does at least have a few important bits, most notably where she gives Superman back his cape, which had wound up at the Daily Planet after Mr. Warfield tried to use it for a cheap headline after Superman's defeat.
In Superman Returns, rising star Kal Penn plays Stanford, one of Luthor's Mooks, and among them gets the lion's share of close-ups, but almost none of his lines whatsoever made it to final cut.
Much of the Tamara Drewe graphic novel is told from the perspective of Beth, Nicholas's wife, but in the movie she's more of a supporting character.
John's co-workers Alix and Tanya's sideplot is omitted from Ted's final cut.
Jeannette, who plays a vital role in the book, appears for a split second in the boardroom at the opening of Thank You for Smoking and has no dialogue. Reitman takes the time to point her out for fans of the book during the commentary.
Adrien Brody in The Thin Red Line. He was originally cast as the lead character and received second billing (though it was in alphabetical order except Sean Penn who was listed first) but only has a very brief and almost mute role in the released cut of the film. Brody learned about these changes from the original script at the premiere,after he'd already been doing press interviews about his lead role.
All of the Hamiltons except for Francis have considerably smaller roles this time around in The Thompsons.
Constance has hardly any screentime in The Three Musketeers, and basically only exists to throw D'Artagnan his sword at the end.
Horseflesh had a big role in the script for Time Bandits, but his lines were removed and he's just more of a background character.
Remember that blonde chick who dances with Fabrizio in third-class in Titanic (1997)? She was written as an opposite counterpart to Rose, a girl who finds her love interest in her class and follows her strict parents' orders without question (down to refusing to go with Fabrizio once the ship begins to sink, despite the fact that he knows the way to the lifeboats better). She's also the blonde girl who hangs on the railing before falling to her death. The film's script identifies her as Helga Dahl (a name she indeed responds to in deleted scenes). The bulk of her scenes in the movie were cut, so it's likely only the most die-hard fans will know anything about her.
Ratchet is a major character in the first movie, but unlike Bumblebee or Ironhide, his screentime decreased massively by the second. The third film does try to give him more spotlight, however. And the fourth film brings him back only to be Killed Off for Real, in a particularly brutal fashion.
He is barely on the screen for 5 minutes in the third film, and when he is, he's barely doing much until the very end. Granted, it is justified as he barely survived Prime's attack at the end of the second film, but it's still a bit of a headscratcher to not have one of the most famous bad guys of the franchise doing much more in this film. Even the small Autobots that stuck with Sam in the third film get more screentime/action than Megatron... The novelization of the film actually works this into the plot.
In which Arcee gets blown up real good. This after much expectation that she would actually do something of note. Ironhide and the other Autobots from the first movie, except for Bumblebee and Optimus, of course, share something of a total of 10 lines between the lot of them. Meanwhile, these memorable characters were replaced with the Twins.
Lennox and Epps had significantly smaller roles.
After having prominent roles in the previous two films, Sam's parents only get three scenes in Transformers: Dark of the Moon, one of which is a flashback to shortly after the second film's events.
Not a huge amount, but Bumblebee has reduced screentime in Transformers: Age of Extinction because Sam isn't in this film. He's still a major character, and seems to bond a little with Shane, but has no more of a role than the other Autobots sans Optimus.
Tron, despite being the title character, is under the control of the villain Clu for almost the entirety of TRON: Legacy, and only appears a few times with very little dialogue.
Lysander in Troy. He has just enough dialogue with Hector to indicate that most of his scenes were left on the cutting-room floor.
Michael Corvin is definitely is this in Underworld: Awakening, seeing as he is practically non-existent in the film aside from one flashback and a single scene where he's shown encased in ice. But one can make the argument that this is also true in Underworld: Evolution as well, as he's taken out of focus for the better part of the middle-to-latter half of the movie, when he finally pops up again to raise some hell. Though to be fair, he was technically dead for a good part of that.
Conrad Heyer, the head of The Eye, briefly appears near the beginning of V for Vendetta when Sutler's advisors are assembled, but the subplot about his wife manipulating him into trying to usurp the government is cut.
Captain Metropolis in Watchmen. In the book, he's a hopelessly naive superhero who forms the Crimebusters in the 1960s and tries to convince them that they can solve all of the world's problems. In the movie, Ozymandias forms the team (re-named "The Watchmen"). Metropolis becomes an unspeaking character who briefly appears in a flashback.
The increased focus on Turtle and Chris in The Westing Game makes this affect all the other heirs to a degree, but Jake Wexler, Doug Hoo, and Dr. Deere in particular don't even get to play the game. The doctor only appears once in the whole movie.
Rogue, as well; she had fairly large parts in the first and second movies, but her storyline here boils down to her being jealous of Bobby and Kitty and taking an apparent cure. Part of it was also because Halle Berry didn't like Storm's comparatively smaller role and demanded a larger part.
Dr. Kavita Rao. Gets about thirty seconds of screen time, three lines in total, and then is Killed Off for Real. Most of her role from the comics (like holding the press conference) is taken over by Angel's dad. She was never a major character to begin with, and was a very recent creation when the movie was made, but still.
Psylocke usually has a fair amount of input on the plot in the comics.
Rogue only appears in a non-speaking cameo and doesn't even get a close-up. This is because all her other scenes were cut out and then restored on The Rogue Cut.
Havok is rescued by Mystique near the beginning and never shows up afterwards. Still, at least he's alive, unlike the rest of the First Class cast, with everyone who didn't appear in the earlier/canonically later films being unceremoniously killed off between films. Of course, he had to survive because in the movie-verse, he's Cyclops' much older brother.
Storm does kick some serious ass, but gets little screen time overall, and doesn't have many lines until midway into the movie. Justified as her part was diminished due to Halle Berry's pregnancy.
Compared to the prominence of her role in the comic version of "Days of Future Past," Kitty Pryde's part is mostly being the means by which Wolverine gets into the past.
Wolverine and Colonel Stryker have an extended cameo.
The Blob is one of Angel's opponents at the East Berlin fight club.
Nebula in the third Zenon movie who only gets a (very badly green screened) cameo since she on vacation on Earth. On the upside, she's played by Raven-Symoné once again.
In 24-Hour Party People, the other members of Joy Division that became New Order. New Order guitarist/keyboardist Gillian Gilbert gets it worse and only appears twice, briefly and in non-speaking parts.
In the Revenge of the Nerds films, Gilbert Lowe is a protagonist of the first movie, a supporting character in the second (he is unable to go to Florida, as he broke his leg while playing chess), makes a cameo in the third, and is entirely absent from the fourth (despite the fact that the movie is about one of his friends getting married).
The original film had fairly equal representation, giving prominent roles to heroes from both franchises and having all of them appear for the Final Battle in a sequence so big it actually won a Guinness World Record. Super Hero Taisen Z was still fairly balanced even with the addition of the Space Sheriffs, but the downhill slide started after this. Ironically, Z could be seen the other way around, since Kamen Rider Wizard sits out for most of the movie after declaring it "Not my problem", only to come roaring back in for the final battle.
Chou Super Hero Taisen is a little better about this, but it's still mostly a Kamen Rider Ex-Aid movie with a few cameos thrown in; the Kyurangers show up at the start, disappear for most of the movie, and then return for the final battle. On the other hand, several Sentai actors return for cameo appearances, they all help drive the plot, and Hebitsukai Silver in particular plays a major role since his status as a Tin Man lets him connect with the Emotionless BoyVictim of the Week.
In Warcraft (2016), Grommash Hellscream, Kilrogg Deadeye and Kargath Bladefist are present, but mostly as visually-distinct orcs rather than actual characters they were in the adapted material.
Went the Day Well?: Bill the poacher is the main character of the short story the film is based on but is only in three or four scenes of the movie And suffers from Death by Adaptation as well.
Professor James Arnold has a much smaller role in Kingsman: The Secret Service than in the comics, in which he served as the Big Bad. The film gives his Evil Plan and main villain status to Richmond Valentine.