In Arrow, the toned down 'no fantastical powers' rule results in this for some characters, by turning them into Badass Normal characters instead.
The most notable character to suffer this at the beginning of the series is Constantine Drakon, considered one of the best martial artists in all of DC and one of Green Arrow's greatest enemies. In the show, he's just a Starter Villain who isn't able to best Oliver in any way and has the added bonus of being Demoted to Extra, getting killed off in his first appearance in the first episode of the series no less.
Harbinger/Lyla Michaels, in the comics, is a super-powered ally of the Monitor and joined the Amazons; in the series she's a former Afghan War vet-turned ARGUS agent and leader of the Suicide Squad, and Diggle's ex wife who he reunites with. Subverted in Season 8, where she's revealed to have been working with the Monitor the whole time.
Shrapnel, in the comics, is a walking pile of scrap metal. In the series, he's a mad bomber.
Laurel is the Black Canary in the comics, one of the best fighters in the DCU. Here, she's an OK fighter at best who can take on a thug or two, but is easily over powered by stronger fighters, with her Canary Cry derived from technology instead of a metahuman power. To rub salt in the wounds, she's anticlimactically killed off by Damien Darhk before she was starting to become a credible Action Girl.
Sara, the show's Canary, also lacks her trademark Canary Cry. Instead, she has a sonic-generating device that has the same effect, so its more of a subversion.
Laurel's Earth 2 double in The Flash (2014) spin-off (known as Black Siren) does have the same ability, being a meta-human.
Kate Spencer is Manhunter in the comics. In-series, she is Starling City's District Attorney who is murdered by one of Deathstroke's minions.
Count Vertigo, in the comics, is a super-villain who is well trained in combat and has the ability to disrupt and disorient opponents using the "Vertigo Effect" from which he takes his name. In the series he becomes The Count, an intelligent and influential but non-powered drug lord who manufactures and sells a narcotic called vertigo which induces a disorienting effect in users.
In the Doctor Strange pilot, Clea goes from being a powerful sorceress who can hold her own alongside Strange to a normal human damsel he has to rescue from the villains.
The Boys (2019): In contrast to the original comic, the title group never inject themselves with Compound V to get superpowers. As the creator explained, doing so would reduce it to another superhero slugfest, while keeping them as average humans put wits as the priority over strength - "We don't need powers to save the world. We just need each other." Eventually Zig-Zagged in Season 3, where Hughie and Butcher both use V-24 to give themselves powers at a cost.
Watson again in Elementary, who has no combat abilities, "just" intelligence. She does get a level in badass combat-wise as the series goes, but 1) it's with stick-fighting/sword skills rather than firearms and 2) by the time she gets these skills she has semi-retired from being Sherlock's sidekick and thus on many plots she is somewhere else doing investigations of her own while Sherlock is having trouble.
Fallout (2024): Lucy in the show is a stand-in for the Vault-Dweller Player Character of the first three games, namely the Lone Wanderer of Fallout 3 whom she thematically mirrors. However while the Lone Wanderer is a One Man/Woman Army that can plow through enemies like a Mook Horror Show and typically is armed to the teeth, Lucy by contrast is a Action Survivor who almost dies many times, loses her finger, and is captured and tortured by the Ghoul. It's not until Episode 4 that Lucy starts Taking a Level in Badass and becomes more capable like the Lone Wanderer and other Fallout protagonists.
In this version, despite his power, the titular character seems totally unable to beat an opponent without the support of his team (the majority of the time). Justified since not only is Barry still relatively inexperienced, he has a bad habit of rushing in without thinking as well as over relying on his super speed, otherwise he'd function as a Story-Breaker Power. He also slowly loses this traitover the course of the series.
Jay Garrick, the first Flash, was a memorable hero who influenced the Justice League in the comics. However, the show outright states that he was afraid of his Arch-Enemy Zoom, and spent every moment trying to run away from the villain because he feared for his life. Flashbacks show that Zoom effortlessly defeated Jay in a one-on-one fight and was about to kill him before the two were sucked into a portal into Barry's universe. Later it is revealed that this Jay was actually Zoom's time remnant, deliberately created to instill false hope into people before crushing it as Zoom. Zoom eventually kills him off, and the real Jay Garrick is revealed to be a Flash from yet another world and a double of Barry's dad. He's also implied to have been a soldier once, restoring his badass status.
Zoom himself is also an example, due to the difference in his powers. While the comic version is a Time Master who is essentially invisible, can create sonic booms by snapping his fingers, and creates rifts in time just by being present, the TV version has standard Super-Speed powers, though they were augmented by Velocity 9. In addition, this Zoom lacks his comic counterpart's mastery of psychology, though he makes up for it by being much better at long-term planning. However, it's entirely possible that this will end up being a subversion, since the Zoom shown here is the Earth-2 Hunter Zolomon, as opposed to his Earth-1 counterpart.
Firestorm in the comic has to ability to manipulate matter, but here is simply a sort of Human Torch. The transmutation ability starts to manifest near the end of the Legends of Tomorrow spin-off (although it's a different Firestorm due to Ronnie Raymond's death and his replacement by Jax Jackson as Martin Stein's other half).
Guest from the Future: Thanks to the episodes three to five being a Pacified Adaptation, all the children except Kolya Gerasimov and Kolya Sadovsky are hit with it. They never fight the pirates; when they finally do encounter them, they are utterly helpless before getting rescued by an adult. Several examples are particularly jarring:
In the book, Alice escapes the pirates when she is cornered by them at the hospital, solely thanks to her quick reactions, and later manages to snatch away Rat's gun in the last fight. In the series, she escapes the pirates in the hospital because, for some weird reason, they only search the ward but don't attempt to kidnap her; and the last fight is entirely omitted. The one time Alice and Rat end up face to face, she meekly lets him take her hostage and is only saved when Kolya Gerasimov distracts the pirates and prompts them to go after him.
In the book, Yulia is one of the best in her class when it comes to sports. She attacks Jolly U at the hospital and contributes significantly to the last fight with Rat, all the while recovering after appendicitis (and in the latter case, with a twisted ankle). In the series, she briefly carries Alice on her shoulders as part of their disguise, but otherwise is just a sidekick for Alice to talk with and never participates in fights.
In the book, Kolya Sulima is a Badass Bookworm who, according to Alice, is going to invent time travel. In the series, he is Demoted to Extra and barely there, and the honor of inventing the time machine is given to Kolya Sadovsky instead.
Jonathan Strange & Mr. Norrell: in the original book the titular Mr. Strange's most notable magical power is his mastery over geography, allowing him to move around mountains, forests and cities like pieces on a chessboard. In the miniseries, on the other hand, he is once asked to move a forest out of an army's way, but finds himself incapable of the task because the trees have wills of their own and resist being moved.
The Last Kingdom: In the novels, Cnut Longsword is renowned for his speed and deals Uhtred a nearly mortal wound at Tettenhal. In the series, their duel is much more one-sided with Uhtred coming out unscathed.
Main protagonist Joel goes from a typical One-Man Army video game player character who can mow down bad guys and shrug off getting shot like nothing to a man who is tough but vulnerable to the effects of old age, relying primarily on ambush tactics and intelligence to win most fights he gets into. He also suffers from aching knees and is deaf in one ear, which lead to him getting jumped from time to time. The university segment is the most clear example of this. In the game, Joel gets wounded after fighting a dozen men and falling off a balcony onto some rebar while grappling with one bandit who surprised attacked him. In the show, Joel just gets stabbed by a broken baseball bat while killing a single attacker.
Tess in the game was easily as competent as Joel, able to casually head shot a goon one-handed and mid-conversation, kill numerous infected in gameplay and save Joel from a Clicker. In the show Tess is noticeably less capable, missing her shots repeatedly with Joel having to do pretty much all the heavy lifting in combat, including saving her and Ellie from the Clickers. Her Heroic Sacrifice is inversely a case of Adaptational Badass however; in the game Tess was gunned down after killing two Fedra soldiers to buy Joel and Ellie time to escape, while in the show Tess succeeds in a massive Taking You with Me gasoline explosion that obliterates a horde of infected.
Ellie is still a Little Miss Badass in her own right, but many of the moments from the game where she displayed her competency and skill are adapted out with the result of her being more helpless the majority of the time. This is seen in the show’s version of the university segment, where Ellie shoots wildly at the bandits and misses them, unlike the game where she effectively protected the wounded Joel from a dozen or so men. Similarly in the Silver Lake chapter in the game, Ellie took the cannibals on a wild Chase Fight (initially on horseback) and it took a good deal of effort for them to subdue her. In the show, they fairly easily knock Ellie unconscious after she lures them away from Joel.
Henry was a muscly and reasonably competent survivor in the game, and he could take on infected and bandits same as Joel and Ellie. In the show, he’s a more of a weedy Non-Action Guy who seeks Joel's help — precisely due to the fact the latter can do what he can’t.
The Lord of the Rings: The Rings of Power: In the books, the Númenóreans are described as being physically superior to normal Men in almost every way. Not only are they far stronger, but also the average Númenórean is taller than 6 feet, while Elendil is described as being between 7 to 8 feet tall. They were also the direct descendants of the Men who fought alongside the Elves in their war against Morgoth and were so mighty that they made Sauron's armies flee and the dark lord himself surrender without any bloodshed when they confronted him. This was after he had forged the One Ring. In the show, the Númenóreans don't look physically distinct from normal Men and are shown to be incredibly inept at fighting, requiring Galadriel to train them personally.
The titular Lucifer was introduced in Neil Gaiman's The Sandman (1989) as the second most powerful being in all creation, second only to the creator, someone who the eternal and undying Anthropomorphic Personification of Dreams and Storytelling feared such that entire issue was dedicated to Dream putting his affairs in order and saying goodbye to people due to the possibility that Lucifer might decide to destroy him. In the show he's an angel, an immortal, and a badass, but doesn't appear to be particularly special compared to the other angels that appear in the show.
Hercules from Once Upon a Time. The Hercules from the myths was able to complete his twelve labors. This version is killed by Cerberus and sent to the Underworld. He also needs Snow White and Meg's help to defeat Cerberus, thereby finishing his labors and allowing him to move on.
Due to being a Pragmatic Adaptation, the non-Devil Fruit using characters with Charles Atlas Superpower are (with the big exceptions of Mihawk, Garp and Kuro) more realistically grounded. For example, in the manga/anime Zoro and Sanji were capable of great feats of Super-Strength despite being rookies in East Blue - in the live action series however they are "merely" very strong by human standards and don't display anything too crazy beyond some wall running, torso bisecting and Sanji sending Kuroobi flying with Mouton Shot, and even then he doesn't literally kick the fishman through Arlong Park like in the manga/anime.
Zeff also got this, partly due to his actions in the Baratie arc and Sanji's flashback getting compressed, but mainly due to being a relatively more grounded character. In the manga/anime version of the flashback, Zeff was shown to be strong and badass enough to kick a mast in half and use said mast to save the swept overboard kid Sanji - here however, all his blood-soaked kicking action happens off screen by the time he encountered Sanji and he doesn't display any super strength. Even in the present as a Handicapped Badass with a peg leg, Zeff could still knock Luffy around and at one point uses Razor Wind from one of his kicks to blow out some flaming pearls flying at him. In the live action series Zeff is realistically well out of fighting prime with Kuroobi able to defeat him effortlessly. Played With though, as in this series Garp the "Hero of the Marines" and rival to Gol D. Roger considers Zeff a Worthy Opponent and respects him as a fellow grizzled geezer. Unlike the manga/anime where Zeff was never considered or mentioned to be within Garp or Roger's ballpark.
Hatchan aka Hachi, Arlong's right hand man, due to being heavily Demoted to Extra and being Hachi In Name Only gets this. He only appears in one scene where he plays cards with Nami, doesn't resemble an octopus and is only named in the credits. This contrasts to the manga where Hachi while the silliest and most gentle of the Arlong pirates (with his better nature leading to him going on a Redemption Quest) was still pretty damn badass, being one of the Sun Pirates and wielder of six swords which he uses to effectively fight (an admittedly wounded) Zoro. In this series however Kuroobi takes his position as The Dragon to Arlong.
Power Rangers Wild Force: A downplayed example but in Hyakujuu Sentai Gaoranger Highness Duke Org Rasetsu is the third Arc Villain and a legitimate threat who is defeated in a mech fight in his first death. His american counterpart, Mandilok, is instead a Big Bad Wannabe who has neither the cunning or motivation to truly menace the rangers like Master Org did and is quickly killed off by the aforementioned villain once he returns. That said, he does get to put up a good fight post-resurrection like his original counterpart.
Preacher: In the show, Cassidy the vampire is portrayed as about a physical match with the Badass Normal Jesse. He's also knocked out by a Tap on the Head. In the comics, Cassidy has Super-Strength and superhuman toughness. He can No-Sell a bullet to the brain, and Jesse has his hand shattered when he catches Cassidy's punch. Jesse's climactic fistfight with Cassidy is portrayed as something of a Did You Just Punch Out Cthulhu? moment for Jesse.
Dream gets this a fair amount, he’s still essentially a Physical God in the show but one that’s much more easily dismissed, bullied and used as a doormat by other characters compared to his comic counterpart. Notably Constantine is able to do what ever she wants in front of him unlike the comic version where Constantine was the one helpless to Dream’s whims during their mission. Similarly the Corinthian was never a real threat to Dream in the comic even with Rose affecting the Dreaming. There’s also Dream’s interaction with the mocking demon Squatterbloat, in the show Dream telling him to mind his tone to the King of Dreams somewhat comes off as an empty threat, whereas in the comic Dream punctuates his warning by easily overpowering Squatterbloat and sending him flying making it a legitimate case of Bullying a Dragon. Not to mention Dream almost gets destroyed during the oldest game and needs Mathew’s support, which didn’t occur in the comic.
Lucifer Morningstar (once again) gets this to some extent by being the one who engages Dream in the oldest game and losing, rather than it being the demon Choronzon. Comic Lucifer was never beaten by Dream in any fashion and merely annoyed Dream had got the better of hell.
Lord Moran in the Sherlock episode "The Empty Hearse". Colonel Moran in the original Sherlock Holmes stories is Moriarty's top assassin who nearly manages to kill Holmes. In the TV series, he's a corrupt politician with no violent abilities. Although the TV Moran is a very minor character, the show's real version of the Conan Doyle Moran turns up in the same season as part of a Composite Character, the Sherlock version of Mary Morstan.
Irene Adler in the original Holmes story "A Scandal in Bohemia" has the primary claim to fame that she is one of, if not the, only individuals to completely outfox Sherlock Holmes. Holmes considers her a Worthy Opponent by the end of the story (not hurt by her Hero Antagonist status), and she even causes him to reevaluate his opinion on women. In the Sherlock adaptation of the story, A Scandal in Belgravia, she loses to him multiple times, only briefly coming out against him, and eventually gets rescued by him multiple times. On top of that, she's also revealed to be working for Moriarty.
Clark Kent aka Superman gets this as he's far less powerful than the comic book version or even other live-action versions for that matter and he's explicitly weaker than Kara who has defeated him, though he's actually proud of her for it. In the comics, while they can be more or less equal Depending on the Writer, Clark is still capable of feats that Kara has never accomplished. Averted in his own show where Clark is presented as ridiculously powerful as the budget will allow, he even manages to shrug off getting shot with Kryptonite at one point, something most versions Supes cannot do.
Mon-El of Daxam in the comics had powers on par with Superman except his Kryptonite Factor was lead, but this version is considerably weaker than the Kryptonians or Martians, having slightly lower Super-Strength and Super-Speed than Kara and being unable to use flight, heat vision or superbreath.
John Jones aka Martian Manhunter also seems to suffer from this in the first season, being subject to The Worf Effect and getting knocked out whenever the plot demands he be unavailable. His telepathy is also much less skillful as he can't erase specific memories without wiping a mind completely. Some of his other abilities from the comics, notably density shifting and martian vision, are absent here. Despite this he's still most likely World's Strongest Man.
From The Tick (2001) we get Fish Boy: lost prince of Atlantis. While we don't really see him in action in the cartoon we do know that he is at least classified as an actual superhero. In the live-action series he's downgraded to a milquetoast of a sidekick, who is constantly physically and emotionally abused by his hero, The Angler.
Extremely common in Titans (2018) due to budget limitations:
Starfire can't fly, though she does retain her energy blasts.
Beast Boy can only transform into a tiger and a snake, unlike his comic counterpart, who can morph into any member of the animal kingdom he can think of.
Superboy lacks many of his powers from the comics, including flight and tactile telekinesis.
Number One aka Luther while he still has Super-Strength, lacks a Jet Pack thus he isn't a Flying Brick like in the comics and is quite less powerful in general. For example, at one point in the show a falling chandelier incapacitates him, while in the comic Luther has bounced back from getting punched through buildings and getting hit with massive explosions. Luther also doesn’t have his fancy (if ridiculous) Ray Gun in show. Like Allison, Luther is closer to his comic version during the glimpse of the Bad Future in the Season 2 premiere, as he shrugs off a missile shot at his back by a Russian soldier, implying Luther has the potential to be stronger than he normally is.
Number Two aka Diego actually had Super Not-Drowning Skills along with his Improbable Aiming Skills with knives in the comics. In the show, however, Diego has only got the knife skills and otherwise is just a Badass Normal. Then again the show's second season does give him some level of telekinesis as he was able to redirect bullets in mid air, a power he doesn't possess in the comics.
Number Four aka Klaus has the ability to converse with the dead same as the comics, however, the sheer scope of his power, the ability to levitate and his Mind over Matter powers are lacking in the show. Especially since comic Klaus actually stopped the piece of falling moon that destroyed everything in the show, with his telekinesis.
Tyreese, due to being introduced later than his comic counterpart and losing his Lancer position to Breakout Character Daryl as a result. In Seasons 4 and 5, they reworked him into a sort of Token Good Teammate who disliked the brutal nature of the post apocalyptic world, and struggled with many moral dilemmas that weren't present in the comic such as forgiving Carol for killing Karen and refusing to kill Martin even after he'd held baby Judith hostage and forced Tyreese to walk out into a small herd of zombies. His Death in the Limelight episode was even centered around Tyreese accepting in his dying moments that he just wasn't mean enough to survive in the kill-or-be-killed setting.
Nicholas was a competent scavenger who proved to be a foil for the equally tough Rick Grimes and even became his friend after failing to overthrow Rick's leadership in Alexandria and ending their feud peacefully with him. However, the show portrays him as a Dirty Coward who is very willingly ready to leave people behind to die to save his own hide. Then it gets worse when the writers made him a villain as well. Thankfully, he pulls a Heel–Face Turn and starts listening to the smarter characters. However, he ends up committing suicide when he can no longer handle fighting through the zombies instead of going down fighting like his comic counterpart did.
In the comics, Dr. Denise Cloyd was a competent doctor in Alexandria and was able to outsmart Rick Grimes. In the show, she is a psychologist who was forced to step up as the new doctor of her safe zone, despite being incompetent at the position, and is completely timid around others. The first time she must perform surgery on a dying patient she fails after cracking under pressure.
The Saviors start out much weaker than their comicbook counterparts. For starters, they suffer from numerous defeats all throughout their debut season and are constantly mocked by Rick's people for underestimating their strengths before they actually had to take a level in badass in order to match up to their original characteristics. Though this trope was deliberately in play in an effort to give them character development as Alexandria's greatest enemy after suffering so many attacks instigated by their people.
The Witcher (2019) gives this treatment to Eyck of Denesle in the episode "Rare Species" which is based of the book Sword of Destiny. In the book Eyck is a truly badass Knight in Shining Armor and dragon slaying monster hunter whom even Geralt considers a rival. Apart from saving Geralt and Yennefer from an avalanche, Eyck actually fights the golden dragon Villentretenmerth himself before getting knocked off his house by the dragon's tail and crippled. In the show Eyck of Denesle is a Prince Charmless and treated like a joke, the only monster he kills is a Hirikka, a creature Geralt says was harmless and would've left them alone if they fed it. Instead of facing the dragon, Eyck is unceremoniously killed while shitting in the woods by the Reavers.
Wonder Woman: In the comics, Etta Candy and the Holliday Girls are a frequent significant help to Wonder Woman and are more than able to handle themselves in dangerous situations. On the TV show, Etta was reduced to comic relief whose high point was berating a Nazi spy for stealing $1.50 from her. Seriously, that was it.
, doing so would reduce it to another superhero slugfest, while keeping them as average humans put wits as the priority over strength - "We don't need powers to save the world. We just need each other." Eventually Zig-Zagged in Season 3, where Hughie and Butcher both use V-24 to give themselves powers at a cost.