Adaptational Personality Adjustment

Sometimes an adaptation features the character you know from the source material. Something feels off, though and you take a closer look. Maybe they like something different from their book, game, or epic saga counterpart.

Then it hits you; their personalities are different! They like different things, have different goals and needs, or behave in a manner contrary to the source.

Generally, the Adaptational Personality Adjustment is more than simply making the character a Jerkass, a Badass, or a Wimp. It can shift them around, but are distinctly different from the source material.

This is one of the more obvious symptoms of Adaptation Decay, and often happens because They Just Didn't Care when it came to making the adaptation. Badly or sloppily handled, it can result in Character Derailment; if a well-known character undergoes a substantial change in personality between versions of a work, it can prompt a They Changed It, Now It Sucks reaction from the audience regardless of how well the change is handled.

Contrast Took a Level in Jerkass and Took a Level In Kindness, which occur within the same version of the character, and are examples of Character Development.

Anime and Manga

 * Sailor Moon when comparing the manga and '90s anime will feature this:
 * Zoicite in the manga mourns Jadeite and Nephrite when the Senshi manage to kill the latter. A sidestory shows him scheming to avenge Nephrite by killing Sailor Jupiter. It's also revealed that in a past life, he was enamored with Sailor Mercury. The 90s anime shows him as The Starscream who schemes to sabotage Nephrite when the latter starts to work smarter, not harder, to find energy and he's in a relationship with Kunzite..
 * Nephrite himself lacks the Hidden Depths that the 90s anime would show. He also used shadow monsters to possess people so as to drain their energy or find the Silver Crystal; in a past life, he was enamored with Sailor Mars. While the shadow attack and Princess D story did happen in the 90s anime, Nephrite's schemes are more insidious: he tracks down one talented person, makes them work to their highest potential while they grab the Jerkass Ball, and drains their energy when that happens before sending a youma after the Senshi when they would inevitably appear. He also went for a pragmatic solution to find the Crystal: ask the stars for a tool that would help him narrow down the location in Tokyo. The black crystal in question helped him figure out that Naru had a connection to the Crystal somehow, and he eventually realized that her best friend is Sailor Moon with some Occam's Razor and a Batman Gambit. What ended causing his downfall? That.
 * The battle gynoid Ifurita from the OVA series El-Hazard: The Magnificent World is a somber, almost tragic figure for much of the series, a Person of Mass Destruction forced against her will to be a devastating weapon for the bad guys until the hero frees her from the Restraining Bolt which compels her to serve whoever possesses her staff. Once free, she gains a quiet joy in life, but remains a soft-spoken, well-spoken individual of obvious intelligence and wisdom, who becomes open to exploring a romantic relationship with the hero.  When El-Hazard was turned into the TV series El-Hazard: Wanderers, Ifurita was turned into a Ditzy Cloudcuckoolander and an Ineffectual Sympathetic Villain loyal to the primary bad guy, mostly played for comedy.

Comic Books

 * For any DC Comics character that has been around since the company's inception, expect this trope to happen. A lot:
 * Batman has multiple versions:
 * Know how much Early Installment Weirdness there was for Batman? An early Golden Age story had him use a gun to kill a vampire after it attacked a woman he was dating. Imagine any 1990s and onward incarnation of Batman that isn't Elseworlds which shows him using a gun without any ethical dilemma, let alone killing.
 * In one version where the Spectre sends Batman and Robin to a universe where another Bruce is still a child and his parents are alive, it's implied this will happen to alternate Bruce. Thomas and Martha Wayne are doomed to get mugged and killed on Bruce's birthday, as they were in canon. Because Batman and Robin interfere to save Thomas and Martha, with Bruce ultimately avenging his parents by stopping their killer in this timeline, his parallel child self never goes through his immense Break the Cutie. The page indicates he will instead instead takes up the Bat moniker, detective work and martial arts as inspiration from the figure that rescued his mom and dad. To a lesser extent, Sergeant Gordon in this version tries to apprehend this masked figure, rather than trust him. He's a lot sterner, but Batman convinces him even if they don't know each other in this universe, they will in another.
 * Dwayne McDuffie pitched a story (which has sadly vanished from the Internet, though the original pitch is referenced on his archived website where Batman is a black man. Uncle Bruce, as an old man and a Cool Uncle to some kids, tells them Batman actually had to deal with more barriers, owing to being a vigilante that couldn't hide his skintone. In his version, Commissioner Gordon had to overcome internal biases, and the men never really became friends.
 * The original Peter Parker in Spider-Man was a well-meaning teenager, but dealing with puberty, being raised by an elderly aunt and uncle, and being bullied for being the school outcast. As a result, he's a bit more irritable and immediately jumps on the idea of using his new spider powers to make money as a wrestler while letting a robber go because the police are supposed to handle dangerous criminals. As a result, he suffers a massive Break the Haughty after that same robber kills Uncle Ben. More modern incarnations of Peter Parker tend to lean towards Adorkable and being nicer; Uncle Ben's death is played up as his Moment of Weakness the one time he tries to be selfish.
 * In Wonder Woman during the Golden Age, Hercules/Heracles suffered this unfortunately. He did cause either Hippolyta's death or Theseus kidnapping her in the original myth, but either was an accident owing to Hera stirring up war with the Amazons on framing him for kidnapping Hippolyta. Hercules in Golden Age Wonder Woman seduces Hippolyta to steal her garter and enslave the Amazons, just because Mars convinced him it was a good idea, rather than needing her girdle to complete his twelve labors. Hippolyta as a result is more of a Broken Bird compared to her portrayal in Greek mythology or A Midsummer Night's Dream, vowing to never trust a man again per Aphrodite's edict.

Film

 * The Japanese Death Note live-action films did this for both Light and Misa Amane.
 * Light's motivation in the manga and anime was pure boredom, picking up the notebook and testing it on a whim. In the movies, he's a law student that wants justice. After he gets mugged, Light laments how the current court systems are useless to help their victims.
 * Misa in the manga, and to a greater extent in the anime, was meant to be a Spanner in the Works ditzy model and actress that upends Light's carefully planned game of cat-and-mouse owing to her obsessive love for him since he avenged her parents. She's more serious in the films, and we actually see the scene where burglars killed her parents. Unlike her manga counterpart, Misa is well aware that Light is not a good guy, as she's crying Tears of Remorse and horror when . The sequel movie confirms that.
 * Harry Potter features this for some characters:
 * Owing to the other Gryffindors being Demoted to Extra, Dean sadly loses any mention of his drawing skills.
 * Book Seamus is an ordinary boy, characterized by his cheerful nature. Movie Seamus gets Running Gag of exploding anything that he points his wand at when performing a spell. Ron snarkily mentioned that he managed to turn water into tea, but there was too much smoke. Neville even gets in a line when he refuses to let Seamus countercurse his Leg Locker jinx because "you'll set my bloody kneecaps on fire!"
 * Book Dumbledore toes the line between Trickster Mentor, Manipulative Bastard and The Chessmaster. While characters lampshaded in The Deathly Hallows that they actually didn't really know him -- Harry realizes belatedly that Dumbledore's instructions to find the Horcruxes are very difficult while he and his friends are on the run, Aberforth had a falling out with him over -- Dumbledore was quite quirky and dangerous at the same time. He also rarely raises his voice, unless he is Surrounded by Idiots, aka confronting Cornelius Fudge. Two actors showed very different interpretations of him.
 * Richard Harris's Dumbledore was dry and serious. His robes are purple, and he walks with dignity. He gets in one quip about Bertie Botts's Every Flavor Beans at the end, when comforting Harry at the hospital.
 * Michael Gambon's Dumbledore in contrast, could be deadpan and snarky at times, with an Irish brogue to boot. His robes are grey-green, that are a lot more understated than the sparkly purple. He's also got a temper, as shown when manhandling Harry about putting his name in the Goblet of Fire and shouting at him. (In the book, "he asked calmly.") Unlike book Dumbledore, who begs for, movie Dumbledore says the same line "Severus, please" with calm and dignity, knowing.
 * How to Train Your Dragon: This pretty much goes for any major character when making comparisons to the original source material:
 * Book Hiccup is a quiet, bookish dragon nerd kid that only snarks occasionally, while book Fishlegs spends his time snarking at the stupidity of the adults around them that are in charge of their lives. The film and franchise reverse their personalities where movie Fishlegs is the bookish dragon nerd kid and Hiccup is the Deadpan Snarker.
 * Book Toothless was a bratty housecat with wings. He spends most of his screen-time refusing to obey Hiccup, coercing fish and treats from him. Movie Toothless is more akin to a panther, and closer to Hiccup's riding dragon Windwalker as well as his elder companion The Wodensfang ; he is a deadly predator that never misses, but also willing to train Hiccup as much as Hiccup trains him.
 * Stoick the Vast is chief in both versions, but book Stoick is more Dumb Muscle defined by the fact that his winning virtues are love for his son and loyalty to his people. Movie Stoick has those virtues, but is a lot more harried with Hiccup hitting puberty and causing trouble during raids. Anyone would get grey hair having to pull their teenage son regularly out of dragonfire range. The Hidden World in a flashback shows part of it is.

Literature

 * In Ella Enchanted, Ella is no typical Cinderella. She's not someone that will demurely do all the chores just because she's asked to; oh, she has to obey orders from anyone who gives them, as long as she understands the language, but she hates every bit of it and will sometimes go for malicious compliance.
 * A Kiss in Time does this for the Sleeping Beauty figure Talia, her father, and the prince figure. Talia is appalled when she wakes up and a teenager is kissing her; he immediately apologizes, saying he doesn't know what got into him because that was really creepy. Turns out instead of a hundred years, she put the kingdom to sleep for three hundred by pricking her finger on the spindle. Whoops! Her father tries to arrest said teen for being a commoner consorting with his daughter, and yells at Talia for courting danger on her sixteenth birthday rather than be grateful that she's alive. Most of the story features the fallout of Jack taking Talia with her to Miami, where they try to figure out how he broke the curse when they never met, and if their bond counts as true love given he's still an immature spoiled teen and she's an immature spoiled princess. The wicked fairy is also shown to be a Fair Play Villain, where after Jack shows he is a Determinator about keeping Talia alive,.
 * The original Sleeping Beauty has the princess still being a conventional lady, graceful and naive before the wicked fairy tricks her. In Spindle's End, in contrast, a rewrite by Robin McKinley, the princess grows up to be a tomboy and Beast Master thanks to the fairy who rescued her, Katriona, calling on the animals to feed Rosie as a newborn. Rosie is appalled on learning about her destiny, because she knows she is not ladylike or a princess. Her friend Peony is more likely to be suspected of being the missing princess, and indeed, so that Rosie can deal with the fairy Pernicia.
 * The 1972 novel Cyborg by Martin Caidin revolved around a former astronaut and test pilot named Steve Austin, who received cutting-edge prosthetic limbs and a camera eye after a devastating crash. In the novel he is a foul-mouthed, irreverent jock, somewhat egotistical and more than a little sarcastic.  When ABC adapted the novel into series of TV Movies entitled The Six Million Dollar Man, he was rewritten into a suave James Bond clone.  Then, when the property was turned into series, Austin became a soft-spoken "aw shucks" nice-guy-next-door hero.

Live-Action TV

 * Pretty Guardian Sailor Moon did this quite a bit:
 * Ami, in addition to her genius nature, is given No Social Skills to boot and a fear that her friends will leave her..
 * Princess Serenity, unlike the manga, isn't a carbon copy of . The first hint is actually that . Far from the sweet-natured princess that would sneak out to see Prince Endymion, this Princess Serenity is revealed to be.
 * Luna isn't quite as strict as she is in either the manga or the anime. Being a plushie cat, she can't scratch Usagi, and there's a hilarious scene where Luna fails to wake up Usagi for Senshi duties..
 * Minako is more serious than her manga counterpart; yes, that counts manga Minako's extensive Break the Cutie in her solo series' finale shortly before she moves to Tokyo to meet up with the girls. She thinks that Usagi is a "baka" if well-intentioned, and treats Rei with condescension for investigating her..
 * Zoicite in the manga was a Manipulative Bastard who brainwashed people to lure Sailor Moon into a trap, succeeding in capturing and nearly killing her. Here he's more of a Neutral Evil, who uses his piano to help either teleport the Shittenou or summon youma..
 * The never-released ToonMakers pilot of Sailor Moon featured this. Rather than Usagi an ordinary, ditzy teenage girl that happens to be a reincarnation for a Sailor Guardian, "Vicky" is the cover for Princess Sailor Moon after she and her friends escape from Beryl when they flee the Moon Kingdom, on Sailor Moon's wedding day no less. She hides sadness about leaving her home, her fiance Earth Prince Darien and her mother behind a smiling exterior and a desire for normal teenage girl things like dances and cosmetics. The other Senshi follow suit: Sailor Mars is a lot mellower than her original counterpart, asking her friends for fashion advice; Sailor Mercury loses the computer and her genius; Sailor Jupiter is more motherly; and Sailor Venus is less of a ditz, showing that she is a serious warrior in battle and a Handicapped Badass to boot.
 * The Sandman has this for a few characters:
 * Joanna Constantine II is more flippant than her comic counterpart John Constantine was with Morpheus. When Dream showed up on John's doorstep, he tiredly agreed to help the King of Dreams. Joanna tells Dream that he has to wait while she handles another exorcism and negotiates to get her fees tripled. Unlike John, who is fairly careful with his artifacts, Joanna reveals she left Dream's bag of sand at an ex's place after ghosting her..
 * Hob Gadling was a Technical Pacifist in the comics; he loses any fights where someone targets him. The show has him take on Lady Johanna Constantine I's goons with his fists, to protect Dream.
 * Greek muse Calliope in the comics is a Broken Bird and all-around Nice Girl. While she is nice in the show, she's much more defiant towards Erasmus when the latter has imprisoned her, and later Richard Madoc when he takes ownership of her. Calliope outright tells Richard that if he wants her ideas honorably, he would free her and then worship her, as the muses used to be worshipped. She also more actively plays The Long Game when the Fates tell her that only her ex Dream can save her; Calliope reads the newspaper and sees the Sleeping Sickness has ended. Knowing what that means, she contrives a Distress Call by writing "Morpheus" on a piece of paper. When Richard says the name aloud and burns the paper, she doesn't react, because saying Dream's name will summon him. Calliope also tells Morpheus she wants to be free, but doesn't want him to think that he still owns her as a wife. She specifies that she doesn't want Richard to be hurt later. Unlike in the comic where Calliope looks at Richard with pity after Dream curses him, she gives a tiny smile.

Newspaper Comics

 * In-universe during Calvin and Hobbes, Calvin thinks that he does this when taking up his various alter-ego persons. Tracer Bullet is an alcoholic detective that regularly skirts bills and courts dames for their cases, Spaceman Spiff is gutsy and adventurous while facing aliens, and Stupendous Man is a mild-mannered hero in civilian form that takes on evil. No one else in the real world buys it, including Hobbes.

Oral Tradition, Folklore, Myths and Legends

 * Hindu Mythology:
 * Parashurama, one of Vishnu's avatars, is immortal, so he makes a cameo in The Ramayana and has a Small Role, Big Impact in the Mahabharata. The sage is known for being a violent ax-wielder with a bad temper, who hates Kshatriyas because a group of them killed his father while the latter was meditating. Yet in The Ramayana when challenging Rama, another Avatar of Vishnu (don't think about it), for breaking a celestial bow, he grudgingly accepts that Rama's archery prowess is divine. He's less reasonable in The Mahabharata when Karna, who still thinks himself a charioteer's son, goes and begs to be his student. Despite the fact that Parashurama has retired from his kshatriya rampages, he still hates them and curses Karna for faithfully letting him rest on his lap despite a bug drawing blood from him, accusing him of being a kshatriya because only royalty would be that durable. Karna, who at this point doesn't know he's actually a prince, begs him to lift the curse and apologizes, saying he only lied because no one will teach a charioteer's son. Parashurama refuses. It is downright petty. Towards the end of the epic,

Puppet Shows

 * When Sam Eagle plays Mr. Arrow in Muppet Treasure Island, he doesn't go with the script where the original Mr. Arrow was a bad-tempered alcoholic that drinks whiskey before going on-deck in a storm, at Long John Silver's inclination. No, this Mr. Arrow is anal-retentive and serious about rules, and he survives the movie due to spending several days testing out a "safe" lifeboat at Silver's suggestion..

Theatre

 * Hamilton has this for a few characters:
 * Angelica Schuyler implies that her marriage to John Church is one of convenience, where they can benefit each other's families financially. In real life, the two eloped long before Angelica met Alexander.
 * Thomas Jefferson in real life had No Social Skills and may have been autistic. The way Daveed Diggs and other actors play him, Thomas Jefferson is flamboyant and a Large Ham, complete with blowing kisses to the audience when he appears.
 * In the otherwise-reviled Spider-Man: Turn Off the Dark, this occurs for the hero and antagonist:
 * Peter Parker is more well-meaning than he is compared to other versions, where he doesn't let a criminal get away after doing his signature wrestling match. Rather than fight with Uncle Ben, he says that he wants to earn money, outright explaining he has other plans as opposed to lying.
 * Green Goblin is given 2002 Doctor Octopus's backstory. He and his wife Emily work together on OsCorp projects, but she dies when one experiment goes wrong. Norman snaps as he holds her dead body and cries, deciding to forcibly transform OsCorp employees into his new Sinister Six, to vent his pain on New York City.

Video Games

 * Deltarune has this for some of the canonical Undertale characters:
 * Alphys is a lot less nervous as Kris's teacher, compared to her original Nervous Wreck personality; while she lacks authority, she's a Reasonable Authority Figure when Kris disappears with Susie in Chapter One, reassuring them that they aren't in trouble for playing hooky. Chapter Two has her inquire on Kris falling asleep in class after Berdly reads A Tale of Two Cities, asking if everything is okay at home with Asriel in college and with the Dremurrs's Internet out.
 * Undyne as the new police chief doesn't even know who Alphys is in chapter one, when before they had Unresolved Sexual Tension. Chapter Two, however, has an optional quest where you can deliver chocolates on her behalf to Alphys, as an apology for knocking her off her bike. Undyne, being Undyne, she says the apology is to the bike and she doesn't have feelings for the fish monster.
 * Unlike his Large Ham Attention Whore personality as a game show host, Mettaton is a Shrinking Violet recluse that refuses to answer his front door. He still calls you "Darling," though, if you call on him.
 * This is a deliberate intention of the Super Robot Wars series, which often has alternate takes on the events of mecha anime canons they integrate, resulting in drastically different characters from the source, most of the time with their perspective drastically altered by the crossover, but sometimes they start off much different from the get go, being based on "what-if" versions of their base character.

Web Animation

 * How It Should Have Ended frequently features this when parodying various movies:
 * The trolls are snarkier in the Frozen parody, saying that Elsa and Anna's parents have mixed-up ideas about how to help Elsa control her powers. They recommend sending her to Professor Xavier's school instead. We also see that Wolverine likes to sing.
 * Ares hates humanity in Wonder Woman, but he and Steve call a brief truce when Wonder Woman pulls her invisible plane out of nowhere and shoots down the German planes with chemical bombs. After a Jaw Drop, they both agree she is a "Mary Sue".

Western Animation

 * Discussed in-universe during Avatar: The Last Airbender when the Gaang sees "The Ember Island Players". Aang complains that the bald woman portraying him shows a mischievous Avatar that can't resist playing jokes on his friends. Katara becomes prone to tears, Sokka is obsessed with food, Iroh is a Lazy Bum and so forth. Zuko, despite his protests to the contrary, is probably the most accurate in the Ember Island show, as he is dark and brooding and goes, "How can you say that?!" dramatically. Katara smirks when the actor proves her point.
 * The animated version of Bunnicula goes with this for all three of the main characters. Harold in the books is a lovable but observant dog that realizes that the title character is not a threat. Chester is paranoid that Bunnicula is evil but goes overboard in putting garlic everywhere. Meanwhile, the worst thing that book Bunnicula does is drain all the vegetables of their juice, something that his family rectifies by putting him on a strictly vegetable juice diet. Cartoon Harold is The Ditz being a dog with more floof than brain, Chester is a Nervous Wreck who is more than willing to work with Bunnicula to solve a problem, if not trusting him that much, and Bunnicula becomes a flying, shapeshifting prankster who will troll Chester if it amuses him.