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Adaptational Dumbass

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Knuckles the Echidna, 2008: Translator of ancient runes.
Knuckles the Echidna, 2014: Illiterate.

When adapting an existing character for a new work the character is often altered in transition from the source material. They might become nicer, meaner, heroic, nastier, more badass, a lot less badass, or smarter.

Then there are these characters, who are actually made dumber; for example, a character who was The Smart Guy in the source material becomes The Ditz in the new one.

A Sub-Trope of Adaptation Personality Change. Compare and contrast Took a Level in Dumbass, where a character decreases in intellect inside the particular work, and Adaptational Intelligence, this trope's polar opposite. Adaptational Nonsapience is the more extreme version.


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    Anime & Manga 
  • Death Note: While Misa Amane wasn't the most intelligent person in the original manga, she did have a good head on her shoulders and was serious about her actions, knew simple, slightly dangerous yet effective plans on how to get what was needed, like in the Yotsuba Arc where she goes off on her own to investigate Higuchi from the Yotsuba group and records his admission that he is the current Kira which played a big role in finishing up that arc. The anime altered her intelligence to the point of downplaying any big moments she had in the manga and even changed her personality to be more airheaded and up-played her Yandere traits towards Light, making her a typical The Ditz character.
  • Dragon Ball Super:
    • Unlike the anime, manga Goku Black is more likely to grab the Idiot Ball, such when he didn't kill Future Trunks after he's weakened from fighting Future Dabura, and actually spares Trunks' life again because he wants to keep fighting him, while anime Black is far more pragmatic and no-nonsense since he tries to kill Trunks every chance he gets and even traps him in the past by destroying the Time Machine. However, the sparing Trunks is justified: much like Captain Ginyu, this version of Black couldn't access anywhere close to all of Goku's power at first, requiring him to use the Saiyan race's innate Came Back Strong abilities to tap into it by having Trunks injure him and being healed by Future Zamasu in turn.
    • In the manga, Gowasu is even more of a Horrible Judge of Character toward Zamasu than he is in the anime. While Gowasu in the anime is aware of Zamasu's issues and tries to help him, manga Gowasu is completely unaware that Zamasu hates mortals until he slices the Barbarian in half, and just harshly tells him to know his place and act like a god without actually trying to quell his issues with mortals. Also, while in the anime, Gowasu chose Zamasu as his successor in part because of his pure heart and strong sense of justice, in the manga, it's heavily implied that Gowasu chose Zamasu as his successor based purely on his battle power, which Whis himself states was a stupid move. Also, whereas Gowasu offers Zamasu and Goku Black a Last-Second Chance in both versions, in the anime, he at least did so while Goku and Vegeta were there and able to back him up; in the manga, he approaches Black to do so alone.
    • Overlapping with Flanderization but Goku himself tends to get hit with this hard in both anime and manga adaptations of Super. Most of his Older and Wiser traits from the Buu Saga are chucked in the bin and he’s far, far more of a fight hungry dumbass who does everything from forget Rice Cooker for the Evil Containment for the fight against Zamasu to inciting a multiversal tournament that will result in trillions of lives getting erased from existence and put his own universe in jeopardy. Not to mention not even knowing what a kiss is or why pregnancy is hard. Granted there is some Revisiting the Roots at play, as Toriyama never intended Goku to be a mature protagonist but it is still disregarding the Character Development he got throughout Z for the sake of humour.
  • Fullmetal Alchemist (2003): Alphonse starts off as an intelligent, insightful young boy who was the sensible one compared to Ed. Later on he makes many very poor, and arguably stupid choices like taking Barry the Chopper's mind games to heart, and distrusting people who he's known all his life. This happens in both the manga and anime, but in the manga, Al learns from this and doesn't do anything like it again. In the first anime it mainly takes effect in the later half, where he runs off every time he gets upset, even though the Homunculi and Dante are looking for and trying to kill them, going along with Shou Tucker's plans and not telling Ed (even though Tucker made his daughter into a chimaera, resulting in her death, and letting Sloth convince him that she's his mother, even though she is a Homunculi when Ed is trying to remind him that they're fighting for their lives, immediately running towards Envy disguised as Winry, right after Ed says it isn't her, and barely putting up a fight. He arguably became more impulsive than his brother, whereas earlier in the show it was the other way around. This could be interpreted as the writers having Al act more like how a real little boy would if they were put in such a situation, but he becomes more competent again in the finale. Other than that he basically becomes quite the load.
  • Ask anyone who only knows the anime adaptation of Kaitou Saint Tail and they'll probably tell you that Asuka Jr. is a romantically challenged idiot who's so confused between having feelings for both Meimi and Saint Tail that he passes them off as having a coincidental resemblance. In the manga, this couldn't be further from the truth: a Mid-Season Twist had revealed that much of what we'd been led to believe about him was inaccurate, and the rest of the plot had upgraded him to the Deuteragonist position as he started catching onto Saint Tail's identity, realizing the true nature of the Secret-Identity Identity problem, and saving Meimi from a mental health crisis out of sheer devotion. Although all of these plot points are carried over to the anime, it also adds tons of episodic Filler that constantly ignores continuity and resets his characterization to the prideful, gung-ho Worthy Opponent stance he had at the beginning of the series without any of the Hidden Depths, leading many an anime viewer to never realize he was actually supposed to have a character arc.
  • The version of Kycilia that appears in Mobile Suit Gundam: The Origin is a far cry from the coldly pragmatic Kycilia that appeared in the original Mobile Suit Gundam, to the point where she almost has more in common with Gihren than she does her original version. While she's not exactly incompetent and still manages to be a major threat, the fact that she possesses most of Gihren's personality flaws (his overconfidence and extreme Lack of Empathy in particular) while lacking in the areas that made Gihren such a threat (including his eerily persuasive charisma and oratory skills) and has her impulsiveness dialed up a bunch means that she's nowhere near as effective at playing politics as the original Kycilia was, and is prone to rash decisions that only worsen things for her side (like having one of her brothers assassinated at a time when political tensions were already high).
  • In Negima! Magister Negi Magi, lead girl Asuna Kagurazaka is a pretty bad student, but shows intelligence in areas unrelated to school. In Negima!?, however... She's basically the dumbest member of the cast and spends most of the series chasing down the mythical Chupacabra.
  • The anime of One Piece does a fair amount of this to crew compared to the manga especially in Filler arcs. For example Zoro get stumped by a path that leads into water and Sanji is willingly to get eliminated by the villain team in a game thanks to the female entourage cooing him into it, while they definitely have these weaknesses in manga it never quite gets as bad as it does in the anime. Luffy is the crowning example however, in the manga he is a Idiot Hero but he at least has some sense of why particular things are important. In the anime however Luffy will infamously try eating a treasure chest before throwing it away.
  • In Persona 5: The Animation, there's a minor case with Ann. During the Medjed arc, a mysterious hacker called Alibaba offers to help the Phantom Thieves deal with Medjed in exchange for stealing the heart of Futaba Sakura, Alibaba's real identity. In the game, Ann immediately realizes that Futaba has the same name as Sojiro Sakura, owner of the Leblanc café and Ren's guardian, after Ren shows her the IM conversation in which Alibaba made the request. In the anime, Ann says that the name sounds familiar, but doesn't make the connection until Yusuke points it out in a scene shortly after the group's first IM conversation with Alibaba. The same could be said for Makoto, who's on the cusp of realizing the same thing before Ann spells it out, but it's possible that Sojiro never told her his name during the scene in which she first met him.
  • Pokémon: The Series: Psyduck in the game is reliable hitter and even with specialized moves like HM it can hit pretty hard. In the anime, it's a total Butt-Monkey who can't even swim (while in the games he's more than capable, both swimming hitting hard with HM Surf) at least until his psychic powers awakened.
  • Tegami Bachi: Letter Bee has Lag show differing levels of intelligence after Gauche seemingly returns to normal after being shot by Lag's letter bullet. In the manga, he gradually realizes something is off, and eventually confronts "Gauche" about the fact that he's still Noir, and the only thing that's changed is that he gained the memories Lag has of him. In the anime, he doesn't suspect anything until Niche, as well as Noir himself point it out to him.
  • Tenchi Muyo!: In the OVA, Mihoshi was a competent cop, but had been overworked to the point that she had a nervous breakdown and was forced to take a leave for her health. She'd just been reinstated when the series began, but she still wasn't back on the ball and made silly mistakes. The third OVA implies that something terrible and traumatic happened to her that caused her mental break, but nothing definite is ever pinned down. All other continuities portrayed her as a ditz from the get-go, with the understanding that she'd always been incompetent. Even worse is that her level of intelligence seems to drop with each continuity, the worst being the version from Sasami: Magical Girls Club.
  • In the mainline Marvel Universe, Kitty Pryde is a Teen Genius, but in X-Men: Misfits she's unable to understand basic geometry, or manage to work her powers properly after weeks of training.

    Comic Books 
  • Batman: Earth One: This universe's version of Batman did not undertake the usual round-the-world crimefighting education backstory Bruce did, so while he has the heroism and fighting skills similar to the traditional Batman, he is a piss-poor detective, to the point of cluelessly trampling all over a crime scene in volume 2 and asking Gordon for tutoring in this area. Volume 3 sees him hiring Catwoman to sniff out the source of the gangs' weaponry when he proves unable to do it himself in the limited time available.
  • Justice Society of America: The series portrays Adolf Hitler as a ranting and raving buffoon who leads mostly because of his cult of personality and charisma than for an any real merit. It further shows several times that he does not fully comprehend the consequences of his actions and is as equally ignorant as he is malicious.
  • New 52:
    • Captain Stingaree was wrong about his hated identical brothers being Batman but he had clear reasons for drawing that conclusion and Bruce himself ensured that his suspicions were (initially) confirmed by having one of said brothers be unmasked by Karl as Batman. His plan was also meticulously plotted out. Post-Flashpoint, his brothers are overweight with absolutely no resemblance to Batman and he accuses them of being Batman while Bats himself is right there. He also generally acts like a loon in a poor portrayal of his adaptation-specific mental illnesses.
    • Batman villain Sterling Sliversmith went from the swordsman runner of a criminal enterprise who just happened to be obsessed with silver and who nearly got away with his brother's murder to a deranged High School teacher whose lessons are useless and who can't control his students, instead spending time whining about them.
  • Downplayed with Tails in Sonic the Comic. He's still good with tools, but he's not the Child Prodigy of the games. Sonic frequently calls him "pixel brain" because of his more naive characteristics. Justified, since this version of Tails comes from the Nameless Zone, which has technology equal to Medieval Britain.
  • Ultimate X-Men: Kitty Pryde isn't the computer whiz her mainline counterpart is.
  • Wonder Woman
    • Wonder Woman (1987): The Amazons as a culture were hit with a stark removal of intelligence, knowledge and scholarship in their Post-Crisis revamp. The original Amazons had a Paradise whose culture was based on scholarship and study along with competitive athletics; they had a small space worthy fleet of ships, hosted troubled children in their school, had advanced medical procedures, welcomed refugees, and regularly played bullets and bracelets as a game. The Silver Age Earth One Amazons weren't QUITE as advanced, but this was a plot point, as the more advanced technology outside of Paradise Island on Earth One FORCED them to be even more isolationist and lead to an attempted coup on Hyppolyte, whom an Amazon scientist believed was holding back their progress. After this coup is suppressed, the Amazons start finding ways to catch up to their Earth Two golden age counterparts. The Post-Crisis Amazons are isolationists trapped in a Bronze Age stasis who are flabbergasted by modern technology and see the first gun they encounter as a mystical artifact to be kept in a vault.
    • In the Golden Age Wonder Woman comics, Tillie Heyday was the smartest, calmest and most responsible out of her four siblings and one of the most rational of the Holliday Girls. In The Legend of Wonder Woman (2016) Tilly Heyday is a clueless, impulsive airhead and easily the dumbest of the Holliday girls.

    Fan Works 
  • In Batman Written by an AI, Batman, normally one of the smartest men on Earth, briefly forgets his parents are dead and seems to genuinely think he's a bat at points.
  • The Boy Who Cried Idiot:
    • Mrs. Johnson believes that Lincoln damaged his textbook and not the raccoon, even though what the raccoon did was bite the book.
    • In Lincoln's nightmare, he mistakes Martin (a redhead) for Clyde (a black boy) from a distance. Then again, it was a dream.
    • When Leni tells Lynn Sr. that "Linky" punched her, he initially doesn't realise she's talking about Lincoln.
  • Xu Shu in Farce of the Three Kingdoms. In the original, he's portrayed as second only to Zhuge Liang (though that is largely an Informed Ability). In this version, he's a Genius Ditz at best, and makes several idiotic mistakes.
  • The Marvelous World Of DC: Downplayed with Diana/Wonder Woman. She's not stupid, but she's not an extreme Omniglot like she is in the comics, and has to rely on her friend Thor to translate English for her. Thankfully, Doctor Strange fixes that problem with his magic.
  • In My Huntsman Academia, Junior is dumb enough to try and pick a fight with all of Team MNVW after Pyrrha alone managed to burn down his entire club. Predictably, they wreck his club pretty quickly. Compare this to his original RWBY counterpart, who was wise enough to remain non-hostile to Yang after she visited his bar again in search of information.
  • Professor Arc: Ozpin is hit by this, along with "adaptational laziness" and arguably "adaptational insanity". While the canon Ozpin certainly makes some questionable decisions, there is at least some logic behind them. In this story, Beacon is run by a man who is unable to handle basic paperwork, wastes millions on near-useless things like a golden lemur statue and appears more concerned about his coffee than about the fate of his school. Only Glynda's vigilance prevents Ozpin from destroying Beacon faster and more thoroughly than Cinder. Then again, some characters think he might be Obfuscating Stupidity, but it remains ambiguous how much, if any of his incompetence is actually fake.
  • The Stalking Zuko Series: Aang is portrayed as more childish and naive than in canon. As a result of his immaturity and stubborn adherence to Air Nomad ideals, his decision-making skills are much worse than in canon and he rarely contributes anything useful to discussions.
  • Total Drama World Tour The Animators Cut: Bridgette gets increasingly naive as she falls for Alejandro's charms and ends up dumping Geoff for him.
  • In Turtles a retelling of Girls und Panzer in which Koume, the girl Miho saved in the finals, comes to Oarai, the student council comes off this way. In canon, they restarted their school's tankery team on a whim during a discussion with a MEXT official planning to close the school, despite not knowing how to play or whether they even have any tanks left, because, as Anzu points out, it was better than just sitting around and waiting for the school to close down. The fic, however, goes into the logistical difficulties of setting up a team and training everyone in more detail, making the student council seem even more naive and foolish. To make matters worse, they don't often listen to Miho and Koume, the two students who have tankery experience, such as when the two of them propose finding an easier opponent than St. Gloriana for a practice match (it's unclear whether the option was available in canon).
  • Mean Rabbit: Unlike canon where he was close to being an outright Genius Bruiser, especially in regards to his analytical ability, Izuku is instead too dumb to comprehend using the various tools on his utility belt in a fight or accept that someone could be significantly faster and stronger than him without a Quirk. Notably, Izuku initially thinks Sir Nighteye has an enhancement Quirk and outright refuses to believe Knuckleduster is Quirkless.
  • A Dip In The Inkwell: In "Powering Down for the Night", Oona is portrayed as being more idiotic in addition to her usual eccentric personality. She's more prone to Comically Missing the Point, going off on long unrelated tangents about various topics, and is a Genius Slob when it comes to washing her hands regularly.
  • While Stoick was a leader set in his ways in How to Train Your Dragon, it was mostly out of concern for the prosperity of his village. In The Dragon and the Butterfly, he allows Berk to fall into ruin when the raids increase out of denial, logics himself into thinking that Hiccup's bond with Toothless is just teen angst and that he would be okay with killing Toothless later on, and repeatedly ruins what little progress he makes with Hiccup by either saying the wrong thing or doing the wrong thing. He had weeks to properly prepare for their assault on the Red Death and a platoon of trained dragon riders at his disposal, yet he ensures that all of the Dragon Riders stay behind out of misguided protectiveness towards his son, turning what was an ignorantly-made Last Stand to an outright suicide mission.
  • In Psychonauts 2, Nick Johnsmith/Gristol Malik, manages to orchestrate his Evil Plan (which included infiltrating the Psychonauts, brainwashing Dr. Loboto, swapping bodies with Truman, manipulating Raz and eventually uncovering the Maligula Conspiracy) all by himself. In Razputin Vodello AU, it was a cult of Delugionists who got him into the Psychonauts, only for him to quit when he fails to find Maligula. It also doesn't occur to him that the Delugionists want Maligula for reasons unrelated to him and his rightful place as Grulovia's Gzar, The Omniscient Council of Vagueness managing to easily fool him into thinking that they were going to make him their leader (as he petulantly demanded) before killing him.
  • Played for Laughs with All Might in 1-X. He already had his issues with being a teacher in canon such as regularly referring to cue cards, but that's taken even further here, regularly forgetting his lines to the point Izuku has to subtly coach him, failing to pull off dramatic movements due to technology errors, and showing himself to be a lot less composed to his students. All of 1-X end up considering him much more dorky in person as a result.

    Films — Animation 
  • Alice's Birthday starts with Alice failing her history exam. In the original books, she is very good at history and admits at one point that it is her second favorite subject after biology.
  • Carface in All Dogs Go to Heaven 2 (and its TV series) may as well be a completely different character compared to his original counterpart.
  • Nourishing in The Amazing Maurice. In the books, she was just nervous and inexperienced; here she's more like The Ditz, with a penchant for Comically Missing the Point.
  • The Angry Birds Movie: Bomb. In earlier Angry Birds media, he was never portrayed as stupid or incompetent (at least, compared to the other birds) and was even The Smart Guy at times. In this film, he is significantly dumber, and is reduced to comic relief many times.
  • Onua suffers from this in BIONICLE: Mask of Light. He was meant to be a wise and mature Genius Bruiser who only seemed dumb because he rarely spoke, analyzing every situation before acting. He was so efficient at saving others, it almost became a running joke. The movie portrays him more as a dim-witted Boisterous Bruiser who rushes into a fight without thinking, resulting in his home town's destruction which nearly cost the lives of hundreds, including his entire team. In the film, he needs to be saved and his only action not to end in an unintended disaster is lifting up a few rocks during the battle at Kini-Nui. The directors claim they based Onua on a stereotypical New York construction worker whose main concern was physical work. Fortunately, later portrayals in books and comics retained his original depiction and some of the traits he displayed in the film would be played straight with actual dumbasses later on, most notably Krekka and Nocturn.
  • Disney Fairies: Silvermist was perfectly normal in the chapter books, being somewhat clever, hard-working and with her main character trait being a calm, unflappable demeanor. The movies turn her into a complete space-case who can't even tell irony or exaggeration from fact ("And she just exploded!" "*gasp!* She exploded!?").
  • The Jungle Book (1967):
    • In Kipling's The Jungle Book, Baloo is the wise, strict but fair, teacher. Old but well respected by the wolves and Bagheera for his vast knowledge of the laws, languages, and customs of the different jungle animals. In the film, Baloo is a goofy, fun-loving, lazy, and rather irresponsible character. And more of a fun uncle/older brother figure to Mowgli than the mentor/grandfatherly figure he was in the books.
    • In the book, Kaa the python, similarly, is a wise Anti-Hero figure who once saves Mowgli's life in the book. In the film, he's turned into an Ineffectual Sympathetic Villain who repeatedly tries to eat Mowgli and fails miserably.
  • In the original Pinocchio book, the Fox and the Cat were two con-men on equal footing. In the Disney movie, the Cat is the Fox's bumbling sidekick.
  • The Green Goblin/Norman Osborn from Spider-Man: Into the Spider-Verse is a far worse example than the version in Marvel's Spider-Man mentioned below. This incarnation of the Goblin is shown to be just a dumb brute instead of being an intelligent, scheming, and manipulative criminal mastermind like most versions of the character. Of course, given his size and monstrous appearance, it's entirely possible that his usage of the Goblin Formula had degenerated his mind to a degree.
  • Ben Riley aka Scarlet Spider gets hit with in Spider-Man: Across the Spider-Verse along Adaptational Wimp. In the comics he’s a Genius Bruiser being a clone of Peter and incredibly skilled fighter. Here he’s got more muscles than brains, Thinking Out Loud to what he sees around him while talking like he’s in a Liefeld comic resulting in him effortlessly falling into Gwen’s trap and being defeated. This was certainly a Take That! from the filmmakers at The Clone Saga as well as '90s Anti-Hero era in general (which are both often considered reasonable targets of mockery) but suffice to say Ben’s fans weren’t amused with the portrayal.
  • Zazu in The Lion King (1994) is often the butt of slapstick and/or rendered helpless due to his small size (something he's very unhappy about), but he's also quite competent, a trusted advisor to Mufasa, and much wiser than the naive, thrill-seeking Simba. The Lion King (2019) dumbs him down into a dopier and more scatterbrained character, to the point where he mistakes his own shadow for that of a predator's.
  • In Norse Mythology, Odin Allfather was famed for his wisdom and cunning, having established his authority over the Nine Realms using trickery and strategic warfare, having sacrificed his eye to achieve supernatural wisdom from Mimir's well. In Legends of Valhalla: Thor, Odin is portrayed as a lazy lout who's grown complacent with all of the free food his worshippers give him, and ends up losing his eye out of carelessness with Mjolnir.
  • The Sword in the Stone: Downplayed — Wart's still smart (albeit in the process of learning), but in the original book, he knew how to read and write just fine. In the film, Archimedes has to teach him.

    Films — Live-Action 
  • Batman & Robin: Whereas the comics Bane was smart enough to come up with a plan to beat Batman, the movie Bane was barely able to speak, only engaging in Hulk Speak and saying one or two words at most when he did. Turning the Genius Bruiser into barely sentient Dumb Muscle is one of the many, many reasons why fans would rather pretend that movie never happened.
  • The Blind Side's portrayal of a young Michael Oher falls under this. The film (along with, to a lesser extent, the book it was based on) portrays Oher as a Dumb Jock who can't succeed on his own merits even while applying himself, both on and off the field. To his credit, the real Oher took issue with this, and wrote a memoir to set the record straight.
  • Carrie (1976):
    • Tommy Ross is portrayed as a Dumb Jock, who was confirmed in a deleted scene to pass Sue's work off as his own in class. In the book, he was noted to be an Academic Athlete, and the poem was genuinely written by him.
    • Billy Nolan was a cunning, calculating sociopath in the book; the reason Chris was with him there was because she wasn't able to manipulate him. In the film, he's a bumbling idiot whom Chris can easily make do what she wants.
    • Carrie herself in a sense. Sissy Spacek's portrayal of her is far more innocent and naive, prone to acting like a child in certain scenes and speaking out of turn. Her climactic massacre at the prom is hinted to be her losing control or going into shock - whereas the book had everything as premeditated revenge.
  • Conan the Barbarian: In the original stories, Conan is a tactical genius who just happens to be super muscular and, well, a barbarian. In the Ahnold movies, he's much, much dumber. This can, however, be explained. The thing is, Schwarzenegger wasn't able to speak English fluently enough for the producers' liking at the time, and staunchly refused to have his dialog dubbed by someone else ever again after Hercules in New York. This carries over to the reboot starring Jason Momoa as well, but to a lesser extent due to the fact that Momoa is a native English-speaker.
  • DC Extended Universe:
    • This continuity's version of Batman is generally less knowledgeable than his previous and subsequent incarnations. In every other version, there's a reason he's the Trope Namer for the Batman Gambit; in this version he's very easily manipulated by Lex Luthor. Also, Batman's greatest weapon is usually being a master manipulator and being Crazy-Prepared. A lot of fans would have trouble believing he would ever face Superman in battle without knowing everything about him, including his mother's name.
    • King Shark from The Suicide Squad. While King Shark has never been a genius in any medium he's appeared in, this one is a childish meathead who only speaks in broken Hulk Speak and has to be herded around from place to place like a small child.
  • Death Note:
    • In the original Death Note anime and manga, Light Yagami is a Teen Genius who is perfectly able to manipulate practically everyone around him. By contrast, the protagonist of the Netflix version is smart, but nothing out of the ordinary, being manipulated instead by the live action counterpart of Misa, Mia.
    • This also applies to the Japanese live action adaptation of Death Note. Light, while still very intelligent in this version, is also more impulsive and makes quite a few mistakes his anime/manga counterpart wouldn't have. Such as feeding Ryuk an apple out in the open when Raye Iwamatsu was stalking him.
    • L goes from being The Chessmaster and an eccentric Bunny-Ears Lawyer detective from the source to an impulsive and overly emotional teenager in the movie; with L showing his face to Light in a coffee shop and openly trying to directly goad Light into revealing himself as Kira during dinner with him. He also has more openness to weaponizing the Death Note for himself, something his counterpart from the anime and manga would never consider a sound option.
  • Enola Holmes: As in the books, this version of Mycroft Holmes has average intelligence and is said to be bitter about lacking the mental gifts of his younger brother Sherlock. In Doyle's original stories, however, Mycroft is smarter than Sherlock, to the point that he occasionally takes control of the British government.
  • Nermal in the Garfield film is portrayed this way compared to in the comic strip. He's just Garfield's comic relief sidekick. In contrast, his comic version is intelligent and sneaky.
  • Frankenstein (1931), the Monster is rather infamously hit with this. In the original novel, he was a fast-learning intellectual who's bilingual and cunning enough to frame someone for murder. In the film, he's a nearly mute brute with an intelligence equivalent to a small child and has trouble even walking right. The film's version is much more well-known in pop culture than the novel's.
  • Halloween: In the original series, Michael Myers was a Genius Bruiser. In Rob Zombie's films, he's more of a straightforward brute with little interest in setting traps for his prey.
  • Harry Potter: A common criticism about the movies is how many of Ron Weasley's scenes in the book changed to turn him into a full comic relief character, and much of his expository dialogue regarding the wizarding world is simply given to Hermione instead.
  • The Joker is one of the most infamous criminal masterminds in fiction, able to concoct complicated, dastardly schemes and match wits with Batman. Joker (2019)'s grittier, more realistic take on the character is too hampered by his mental illnesses to pull off that kind of supervillainy, and most of the havoc he wreaks comes from being in the wrong place at the wrong time.
  • In the original animated Disney version of Sleeping Beauty the Three Good Fairies were a bit bumbling but fairly competent, to the point they could be easily considered the heroes of the film. By contrast, in Maleficent they are totally incompetent twits who are utterly incapable of properly raising Aurora.
  • Mary Goodnight of the book The Man with the Golden Gun is an intelligent and competent assistant to James Bond. In the movie, she's a classic Dumb Blonde who makes things worse several times.
  • Marvel Cinematic Universe:
    • Guardians of the Galaxy does this quite a lot for the sake of laughs. Most notably Drax the Destroyer in the comics is nowhere the near the Literal-Minded simpleton that he is in the MCU. Mantis likewise in the sequel is equally dim and alongside Drax in the Christmas Special wreak havoc with their chaotic stupidity, this is a stark contrast to the comic where Mantis is a fighting genius who impressed even Vision with her mind. Adam Warlock in turn gets this as well, being a Genius Bruiser and Warrior Poet in the comics whom even Thanos respects, whilst in his debut he’s more of a naive Manchild. Justified in Adam’s case at least since he was only just recently hatched and Born as an Adult so his lack of smarts is an absolute given.
    • Downplayed with Black Panther, since the MCU's T'Challa is still smart enough to make some of his own gear and run Wakanda, but he's also more down to Earth, whereas the T'Challa of the comics was The Chessmaster and among the Marvel Universe's 10 smartest characters.
    • In the comics, The Shocker was a genius inventor who created his own gear and a pragmatic tactician who evaded capture many times. Spider-Man: Homecoming portrayed him as a common thug who relied on the Tinkerer to make his gear and show him how to use it. This applies to both Jackson Brice and Herman Schultz, although the former is clearly the dumber of the two.
  • The Muppet Christmas Carol: While not stupid by any means, the Muppet version of The Ghost of Christmas Present is shown to be rather absent-minded and often forgets what he was talking about. He explains that, due to specifically embodying the present, it's difficult for him to focus on anything other than the here and now, an idea unique to this version of the story.
  • The Naked Gun does this with Frank Drebin, relative to his appearances in Police Squad!. In Police Squad, he's generally shown to be a highly successful cop, bordering on The Ace, with his main joke being the fact that "competent policework" in the world of the series is totally ludicrous and yet he handles it with the utmost seriousness. In The Naked Gun and its sequels, he's shown to be more of a bumbling idiot who frequently screws up and isn't given much respect, being more of an Accidental Hero.
  • Sleeping with the Enemy's film version makes the heroine much stupider than she was in the book. In the latter, she kept her wedding ring on while the film has her flush it down the toilet (and that's one of the reasons her husband discovers she's faked her death). She keeps her wig on in Iowa, while the film has her take it off as soon as she gets there. Additionally, the circumstances surrounding how her husband discovers the swimming lessons are changed; in the book, he just bumped into a friend at the supermarket who was eventually cajoled into revealing the lessons. In the film, Laura gave her name and number, and one of the friends phones the husband to offer condolences. She's also much more tight-lipped in the book than the film.
  • Played for laughs in Team America: World Police with Matt Damon. While by all indications a pretty thoughtful guy in real life, the puppet of him "came out looking retarded" in the manufacturing process per Trey Parker and Matt Stone's words, so they changed his personality to fit. In the film, he can only say his own name.
  • Downplayed in the X-Men Film Series. While Wolverine is by no means stupid, the film version lacks his comic counterpart's worldliness and Cunning Linguist skills. In fairness, the film version is suffering from amnesia for most of the time we see him for, and he is shown to be fluent in both French and Japanese at various points.

  • Godzilla vs. Kong — The Official Movie Novelization has an exchange that wasn't present in the finished film: Mark Russell and Director Guillerman can't decide straight away whether they're rooting for Godzilla or Mechagodzilla. This would normally be quite reasonable, except that MonsterVerse Godzilla is normally exclusively heroic, whereas Mechagodzilla just annihilated several blocks of Hong Kong filled with people simply because he could. The book also confirms that Mark Russell hasn't been the best father since Madison started to live with him following her mother's death, whereas the movie only suggested this was the case.
  • Maskerade which adapts/spoofs The Phantom of the Opera gives this treatment to Christine to an even greater extent than the musical (see below in Theatre). While musical Christine at least got to keep her great vocal talent in the latter despite losing her agency and bravery from the book, in Terry Pratchett’s version Christine lacks even her great singing voice being a Innocently Insensitive Brainless Beauty who only gets by through her looks and a father pressuring the owners to get her a leading part. This was likely an intentional jab from Pratchett to highlight the shallow standards of the industry as the real protagonist Agnes Nitt has all Christine’s musical strengths from the source material but doesn’t share her beauty thus is looked down upon.
  • Nigel Bruce is notorious for depicting Watson from Sherlock Holmes as a heavyset buffoon, while in the original books he was a Badass Bookworm former British Army doctor. Parodied in a strip of Hark! A Vagrant, in which two different Watsons appear, one of whom really loves his jam.

    Live-Action TV 
  • In Cadfael, a plot point in "The Devil's Novice" is condensed by making the involved characters either hubristic or stupid. The dead man, Peter Clemence, is identified by his fancy jewelry, and it's revealed that Tristan, Roswitha (Rosanna in the show) and Janyn were involved in the murder and cover-up when Roswitha's bridesmaid quietly pins Clemence's large cloak-pin to Roswitha—in the excitement of the wedding, they don't notice until Cadfael and the other investigators point it out. In the show, Rosanna chooses to wear it, even though it's just as big and distinctive as it's described in the book.
  • Game of Thrones:
    • In the books, Sansa can spout historical and literary trivia and identify Renly and Barristan purely by Sherlock Scan, but in the show, she literally thinks "shift" is a vulgar word for dung. She also remains oblivious to subtle character clues like Loras's chivalrous disinterest and Littlefinger's Stepford Smile instead of sensing them after a single conversation, and she trusts her mysterious new maid "even though she tells me not to" rather than assuming she's a spy (which is true of her maids in the novels).
    • Arya is a lot more heedless and prone to Revenge Before Reason than in the books where she prefers to avoid confrontations and only fight when she has no other choice. For instance, in "Mhysa", she attacks a man-at-arms for bragging about desecrating her brother's body without any heed to his comrades which simply doesn't happen in the books, and in "Two Swords" she's intent on confronting several soldiers at an inn despite the Hound's protests, while in the books it's the Hound who rushes into the inn despite Arya's protests and she only loses control on the last man standing at the end of the fight.
    • Robb is made more brash and impulsive due to the show's changes to his marriage. In the books, he marries Jeyne Westerling to save her from being Defiled Forever by their one-night stand fully knowing it's a terrible move but choosing Jeyne's honour anyway. The televised version sees him marry Talisa because he can't control his raging... love for her and refuses to hear what a stupid move it is. He also brings his entire court to the Twins for the Red Wedding in the show, resulting in all of them being either killed or captured. Granted, he doesn't foresee the betrayal in the novels either, but he does recognize the foolishness of keeping all his eggs in one basket and therefore leaves his wife at Riverrun with the Blackfish rather than bringing her with him.
    • Stannis needs to be told of the Lannister incest by Ned and the Dance of the Dragons by Shireen in the show. In the books, he's the first to raise suspicions of incest and co-investigates with Jon Arryn, and he knows enough history to specifically include a faction leader of the Dance in a list of historical traitors. He's also initially very cynical of Melisandre and her religion in the books but dives right into fundamentalism in the show, and his military tactics always seem to boil down to direct assaults.
    • Mace Tyrell isn't the sharpest knife in the drawer in the books either but he's far from the clueless oaf depicted in the show. For instance, his feasting at Storm's End is implied to have been a psychological weapon against Stannis's starving garrison and he personally commands the right wing of the army in the Battle of Blackwater, which are things that are very hard to imagine him doing in the show.
    • Roose Bolton, for all his political and psychological savvy, can't seem to see what a viper Ramsay is and openly rebels against the Lannisters before he's ready by marrying Ramsay to Sansa (which is never actually shown to win him any support), leaving Littlefinger free to descend on them with an army. Contrast this with the books, where Roose keeps Ramsay on a short leash by controlling his goons and strengthens his ties to the Lannisters by acquiring an imposter Stark bride from them, which brings half the North at least begrudgingly to his side and provides him thousands of reinforcements from the south. In addition, the book version of Roose doesn't constantly antagonize his psychologically unstable son by threatening to take away his inheritance. In fact, he's creepily at peace with the fact that Ramsay will eventually kill his other heirs since he himself is too old to raise new sons to manhood and "boy lords are the bane of any House."
    • The show portrays the Sand Snakes as Dumb Muscle whose main pursuits are bickering and trying to kill people, and even when they try to get involved in diplomacy they're just insulted and told to "let the grown women speak." In the books, they're still stubborn and hotheaded but only Obara could even be accused of not also being cunning and politically aware and Doran even tasks Nymeria and Tyene with infiltrating the Small Council and the Faith Militant for him. Tyene Sand, although still a Master Poisoner, in the show displays none of the cunning she does in the books when she suggests invoking Dorne's gender-neutral inheritance laws to crown Myrcella as a rival to Tommen in an attempt to lure the Lannisters into an unwise attack on their Thirsty Desert kingdom. Instead she comes across as merely a petulant Psychopathic Womanchild who still calls her mother, "Mama."
    • Hand in hand with other deviations, Jon makes more mistakes or just doesn't get to be as clever as in the novels, particularly in his leadership which—unlike The Strategist of the novels—mostly amounts to being a Frontline General in numerous battles and skirmishes, many of which are likely or even unequivocal defeats until The Cavalry bails him out. He also often neglects or delegates important administration whereas in the books he's something of a Badass Bureaucrat Pen-Pushing President who competently institutes major logistical reforms and frequently negotiates treaties, alliances, and loans. Some fans chalk this divergence all up to not spending enough time being mentored by Qhorin Halfhand in Season 2.
  • The Lord of the Rings: The Rings of Power: In the lore, Galadriel was suspicious of Annatar, who was Sauron in disguise, pretty much the second she met him. Here, she developed feelings for Halbrand, an identity forged by Sauron, and only found out who he was after finding evidence that he was lying about his identity. What's worse is that even after after finding this out, she decides to keep it a secret out of shame, even though Sauron knows that the Elves were going to forge the Rings of Power.
  • In The Muppet Show (1976), the Swedish Chef, while clumsy and a little scatterbrained, is still a competent chef, whose sketches' humour is usually derived from the bizarre ways he cooks (often involving large weapons), the food itself fighting back (typically when it's a live animal), or something completely out of left field happening (such as when he discovered he had a coffee pot growing out of his head). In Muppets Now (2020), the Swedish Chef cannot handle a single thing correctly in the kitchen, and usually just makes a mess while the guest star (a real-life celebrity chef) demonstrates a recipe. In one episode, he can't even make rice properly without both a rice cooker and his kitchen aid Beverly supervising him.
  • Happens a few times in Power Rangers, which adapts Japan's Super Sentai series, and it tends to overlap with Demoted to Extra:
    • Consider America's Time Force vs. Japan's Timeranger. In Timeranger, futuristic crime lord Don Dolnero is the Big Bad, at least at first. In Time Force, Dolnero is renamed Gluto, and he's the hapless comical minion of the mutant terrorist Ransik.
    • In Japan's Kyoryuger, the Big Bad is a reptilian beast called Deboth, who later evolves into a smarter human-shaped form. America's Dino Charge replaces him with Sledge, an evil alien bounty hunter with different motives. Deboth's bestial form is repackaged as Greenzilla, Sledge's ultimate weapon.
  • Persuasion: The original book versus ITV's made-for-TV movie adaptation:
    • Mary Musgrove of the book is a self-absorbed, whiny woman constantly seeking attention, mostly by playing sick. She's certainly not the sharpest tool in the box, but nothing in the book suggests that her intelligence is below average. In the 2007 movie, she's absolutely, utterly idiotic and behaves like a lunatic, always twitching and jerking about, unable to read other people, speaking with a nasal voice and laughing and whining all the time and manages to embarrass herself at every opportunity.
    • Charles Musgrove is a fairly intelligent and friendly chap in the book. In the 2007 adaptation, he's a stupid, ditzy guy who doesn't seem to realize how embarrassing his wife is and behaves like a dimwit. For instance, unlike in the book, he doesn't seem to realize that his wife only pretends to be ill.
  • Jessica Wakefield in the television adaptation of Sweet Valley High. While her academic performance tended to vary in the books Jessica was almost always depicted as smart, sometimes extremely so. The TV version ranges from being cunning but Book Dumb to being a Brainless Beauty whose stupidity causes any scheme she embarks on to implode.
  • The Worst Witch's 1998 series.
    • Agatha Cackle becomes far more Stupid Evil in the series (admittedly this is due to Adaptation Expansion giving her more screentime than the half a chapter she had in the book) and prone to evil gloating - which allows others to either figure out her evil plans or surprise her.
    • Miss Bat becomes a Cloud Cuckoo Lander in the series, as opposed to her stern and strict persona in the books. She even flirts with being a Misplaced Kindergarten Teacher.
  • In the live-action drama based on Yamada-kun and the Seven Witches, Ryu Yamada's inability to grasp complicated concepts reaches new heights. In the drama, he generally cannot understand any of his friends' observations without long explanations, the most noteworthy example being when Shiraishi has to use five minutes of an episode to explain to him how his copy power works, and whose powers he has copied. In the manga, the same conversation only takes a few panels, and Yamada immediately grasps what's going on once Shiraishi mentions that she is the one with the body-swap power.

  • The Phantom of the Opera: Christine would get hit with this like a ton of bricks in Andrew Loyd Webber’s version of the story. In Gaston Leroux‘s original novel Christine certainly has naive traits but she’s still pretty damn intelligent, has a great deal of pluck and understands the danger she’s in after the Phantom reveals himself to her. The musical version of Christine is firmly The Ingenue and is completely susceptible to the Phantom’s mind games, genuinely believing he is supernatural for most of the musical unlike the novel.
  • Hamilton: In "Hurricane", Hamilton decides to write the Reynolds Pamphlet out of paranoia that his enemies would reveal his secret, but in real life it was for a far more sensible reason. By the time the pamphlet was published, the speculation charges mentioned in "We Know" had made their way to journalists and were publicly released, with said journalists openly accusing Hamilton of financial crimes. Thus, Hamilton released the pamphlet hoping that by admitting to the affair but denying the financial crimes he would be considered trustworthy and the charges would be forgotten (it actually worked too, but his reputation never fully recovered). In short, the historical corruption charges were already public, so his release of the pamphlet made more sense, while the theatrical corruption charges see Hamilton try to get out ahead of them and come out looking worse off for it.
  • Westeros: An American Musical: In the original story, Bronn could be suprisingly smart for a low-born sellsword. His parody version is a fairly minor character whose vocabulary is reduced to Pokémon Speak, which makes it hard to portray him anywhere near as smart as his canon counterpart.

    Video Games 
  • Throgg in Warhammer, particularly in the End Times, is a highly eloquent, philosophical and well-spoken servant of Chaos. In Total War: Warhammer he is intelligent... for a troll, speaking in broken English, frequently talking about eating his enemies and being quite dumber. The description of some of his skills do hint that the intelligence might still be there, but voice-wise, it doesn't really show up.

    Web Animation 
  • FreedomToons: The way that Dave Rubin is portrayed is basically FreedomToons's answer to Team America: World Police's Matt Damon. The only barely coherent phrase he can utter is "I agree with that".
  • SMG4:
    • It's probably safe to say that most of the Mario cast was hit by this, but none more so than Mario himself. Canon Mario is intelligent enough to qualify for a doctorate and can come up with a cunning plan when needed. The SMG4 take on Mario can't even count and probably qualifies as having brain damage.
    • Steve from Minecraft also qualifies, as he is even stupider than Mario.
    • "SMG4's Origins" ends up explaining just why everyone has room temperature IQ. We see the world as it was before the first blooper and it shows the cast much closer to their canon counterparts until the Guardian Pod that SMG4 came in and acted as The Corruption, which caused the populace to lose intelligence and sanity. When Mario took a hit from it at point-blank range, we see him transform into the cross-eyed, big mustached, gaping mouth version he appears as in the videos.

    Web Videos 
  • While Ron wasn't exactly the most Book Smart of the trio in Harry Potter, he was born and raised in a Wizarding Family and was the most intuitively familiar with Wizarding customs of the trio. In Welcome Back, Potter, he's a Fratbro that does whatever Jarry says and comes across as a total ditz.

    Western Animation 
  • The Addams Family (1992) made Pugsley Addams significantly dumber than he was in previous continuities, in contrast to being a boy genius in the 1960's live-action television show and 2019 MGM animated film and having average intelligence in the live-action films by Orion and Paramount.
  • While he was still able to threaten a scientist into building him a suit to contain his powers, Mr. Freeze's counterpart in The Batman isn't a scientist like most other incarnations.
  • Bunnicula: In the books, Harold is the smart one out of the three pets, having to put up with the scatterbrained Chester and the hare-brained title lapin. But in the TV series, Harold is often portrayed as being impossibly stupid in comparison to the now-competent Chester and Bunn.
  • Chase Devineaux in the Carmen Sandiego Word Detective and Math Detective games was one of Carmen's former partners, and whom she considers a Worthy Opponent as he gives you instructions on accomplishing your goals. In the Carmen Sandiego Netflix series, Chase tends to grab the Idiot Ball more than once, and Carmen easily outruns him. He also seems to have little knowledge of history and geography, making him less capable of seeing the big picture of Carmen's plans and his obsession with capturing her makes him blind to the times where she is not the enemy.
  • In Clerks: The Animated Series, Randal is much dumber than he was in the original film (and also more self-assured).
  • Curbside, an unsuccessful pilot revolving around an Animated Anthology starring revamped versions of Terrytoons characters, gave this treatment to Muskie Muskrat from
  • The Cuphead Show!: In the game Cuphead could do some dumb things due to being impulsive and greedy, but otherwise seemed fairly average in intellgence, while in the show he's a borderline Idiot Hero to the extent that it's a miracle he hasn't killed himself yet.
  • DC Animated Universe:
    • Batman: The Animated Series:
      • The series's take on Hugo Strange is far less clever as a manipulator or as an inventor than his Psycho Psychologist and Mad Scientist comics counterpart.
      • While not a complete idiot like in Batman & Robin, Bane still isn't as smart as his comics counterpart, who's a strategist on par with Batman and even figured out Bruce was Batman.
    • Justice League reimagines Dr. Destiny as a petty criminal who got his powers via volunteering for experiments with a device called the "Materioptikon". In the comics, Dr. Destiny was a Mad Scientist and, while The Sandman (1989) revealed that the power source was Morpheus's dreamstone, the Materioptikon was something that he built himself.
  • DuckTales (2017)
    • In the comics and original series, Dewey was just as smart as his brothers, the latter indicating at times that Dewey was slightly more intelligent than Huey and Louie. Here, he's by far the dumbest of the triplets, having little to no sense of caution, and is heavily implied to have suffered brain damage from being dropped as an egg. Despite this, he still shows some moments of intellect during adventures from time to time.
    • In Darkwing Duck Steelbeak was one of Darkwing’s smarter enemies, being able to get the upper hand on him on several occasions and often didn’t fall for his disguises and traps, and was competent enough to command a small army. Here, he is a complete idiot who can’t do anything he is commanded to right, messes up easy tasks, and works as a henchman rather than being a boss. That said, Word of God explains that he just recently joined F.O.W.L. and will grow more dangerous in his subsequent appearances. And sure enough, in the series finale he uses the Intelliray on himself to become smarter and becomes a Diabolical Mastermind as in the original show.
    • This is also the case for Flintheart Glomgold. In the comics and original series, he was a clever schemer. In this show, he is a complete moron to the point he called for tails when flipping a Two-Headed Coin and actually believed Scrooge died from a disease made up by Glomgold himself.
    • It gets zig-zagged from time to time with Launchpad McQuack, Depending on the Writer. Many an episode depicts him as a little on the dim side compared to the laid-back version seen in the original, sometimes showcasing him as being unable to discern a movie from real life. Other times, he just a very enthusiastic pilot who happens to show a lot of Hidden Depths. That being said, every depiction holds no bars when it comes to his infamous tendencies to crashing anything, including himself!
  • Harley Quinn (2019)
    • The show's version of Bane is not the Genius Bruiser of the comics or The Dark Knight Rises (despite his voice mimicking the latter), but rather a big nerd who likes smoothies, magic tricks, and stand-up comedy, with a very short fuse and an obsession with Stuff Blowing Up. He's not as dumb as his iteration from Batman & Robin though, and he shown to be incredibly dangerous when he needs to be, and surprisingly well adjusted compared to his fellow villains, making him one of the few villains in Gotham that Harley actually likes.
    • Clayface is also hit with this. The original version was no genius by any stretch of the imagination, but he at least was clever enough to hide himself in plain sight until the situation called for it. This Clayface, however, is so meticulously obsessed with being an actor that he often blows his cover or makes crucial mistakes to stay in character, to the point that others are easily able to pick up on his duplicity. That being said, he does get a little smarter in Season 2.
  • The Looney Tunes Show:
    • Daffy Duck in the original shorts was more gullible and a bit naive than anything else but he was portrayed as intelligent when it suited him. In The Looney Tunes Show, he is portrayed as a total dumbass who can't do anything right.
    • Lola Bunny, although she doesn't get many lines, seems reasonably intelligent in Space Jam. In The Looney Tunes Show, she's a total Cloudcuckoolander It's somewhat inverted with New Looney Tunes, where she is more competent again but still fairly crazy.
    • Cecil Turtle gets this along with Adaptational Jerkass and Villainy in The Looney Tunes Show. Cecil in the original shorts was one of the few characters to ever beat Bugs Bunny by outwitting him. He was also one of the few to see through Bugs's obvious disguise, but plays along in order to exploit Bugs's bruised ego and trick him into giving himself a disadvantage. Cecil here, as a result of being the one to antagonize Bugs first, ends up on the receiving end of Bugs's karmic trickery, falling for Bugs's disguises and being played like a fiddle. In his second appearance when he has Bugs and Porky at gunpoint, Bugs exploits his ego by making him share the details of his crimes and tricking him into siting back on Daffy's broken recliner, knocking him out.
  • While by no means dumb, Norman Osborn in Marvel's Spider-Man gets blindsided by his arrogance more often than in other incarnations, such as failing to realize Otto Octavius was going to betray him as soon as he told Otto that he owns Otto's tech.
  • My Adventures with Superman:
    • The titular character gets hit with a downplayed case of this trope. He nowhere near an idiot and overall fairly intelligent, unlike his comic counterpart, he's absolutely terrible at keeping his secret identity under wraps, regularly displaying his powers in obvious ways and then coming up with unconvincing lies to try and cover it up. Lois is quickly able to deduce that Clark is Superman partly because of this, while Jimmy is revealed to have known about Clark's superpowered status for years because he kept accidentally breaking things and coming up with unbelievable excuses.
    • In the comics, Heat Wave invented all of his own tech and has never had any problems with maintaining them. This show's version of the character, meanwhile, not only didn't invent her tech, but also doesn't seem particularly good as maintaining them, with them constantly malfunctioning throughout her debut episode.
  • Scooby-Doo:
  • While the 1965 version of Morocco Mole from Secret Squirrel was a Bumbling Sidekick, in the 90's revival, Super Secret Secret Squirrel, he's outright Too Dumb to Live.
  • Happens in-universe in The Simpsons episode "Homer to the Max". The character Homer Simpson in the Show Within a Show Police Cops starts out as a smart badass hero in the pilot episode, only to be replaced with a Bumbling Sidekick in the series proper, much to Homer's (the real one's) dismay.
  • Sonic the Hedgehog:
    • In the original games, Sonic was an excellent combatant and could impart great insight in general to others on occasion. He was also pretty sharp-witted, with official sources stating that Rouge sees him as the one guy she can't outsmart. Contrary to this, SatAM and its tie-in comic made him rather ignorant and Book Dumb (game!Sonic was established to enjoy reading books on rainy days), as well as much more reckless, immature and full of himself, usually so that he would play the role of the ever-wrong Red Oni to Sally's always-right Blue Oni.
    • Similarly, Tails was a kid Gadgeteer Genius in the games. The 90s western cartoons and comics ignored this side of him, turning him into a more stereotypically immature Kid Sidekick and Tagalong Kid. SatAM notably had Canon Foreigners Rotor and later Sally play the role of Gadgeteer Genius instead, with Tails being Demoted to Extra as a result.
    • Sonic Boom:
      • In the original games, Knuckles was merely Super Gullible and poor at dealing with people, having lived in isolation for most of his life. He was still able to perform such feats as translating ancient runes. Here, he's little more than Dumb Muscle; he's illiterate, it takes him a few seconds to understand left from right and he can't even count.
      • Dr. Eggman. While his game counterpart was also a comical character, he was more of a Not-So-Harmless Villain, capable of concocting good plans and being a real threat. This incarnation is more of an Ineffectual Sympathetic Villain who tends to come up with ridiculous plans that rarely pose a major threat.
  • Spider-Man: The Animated Series: In the comics, the Hobie Brown version of the Prowler was a Gadgeteer Genius and made his suit himself. In the series, Hobie has no such skills and has to turn to The Kingpin's men to get his suit.
  • Tak and the Power of Juju (2007) made Tak noticeably dumber than he was in the video games.
  • Teenage Mutant Ninja Turtles
    • The 1987 series Turtles and Shredder from Turtles Forever are portrayed as reckless, immature, pizza obsessed idiots and a clownish buffoon respectively. In Teenage Mutant Ninja Turtles (1987), the Turtles were a lot more careful in their actions and while they didn't think things through from time to time, they weren't as dumb and incompetent as the film made them out to be, Leonardo and Donatello took most situations seriously, and Shredder though having comical moments here and there could be a major threat and was a competent fighter who usually got the better of the turtles in hand to hand combat.
    • While Michelangelo has been depicted as the most laid-back and even bumbling member of the turtles before, his 2012 counterpart is a complete idiot. From nearly getting the Turtles killed by Shredder because he wasted all their smoke bombs previously for the most trivial of reasons, to nearly getting himself killed by pouring experimental goo of Donatello's on himself that was clearly labeled as toxic and dangerous. The episode "Journey to the Center of Mikey's Mind" even revealed he never mentally matured past the age of six.