Adaptational Weakling

In an original work like a book or graphic novel, you have a powerful character. Maybe they are The Ace. Or they are a god, that demonstrates omnipotence. You respect their power.

But where's the fun in that when you adapt said work to a movie, television show, or anime? Where are the stakes when your character can beat down their opponents with ease?

The Adaptational Weakling, the opposite of the Adaptational Badass, can still be strong, just not as strong as their original counterpart. If a character is still supposed to be badass but is shown easily defeated in an adaptation, they might be victim of the The Worf Effect. Chickification is often a subtrope, when a girl who was previously a capable combatant becomes kidnapping bait. Sometimes the creator's intention is to raise the stakes. Other times, it's to further character development or aim for a change in tone.

Note: on TV tropes, this is referred to as Adaptational Wimp, but going with Weakling since it's a close-enough synonym and we don't have to debate on the name.

Anime and Manga

 * Sailor Moon
 * It's revealed that the Silver Crystal users in general are this in the anime. The users can do anything with the Silver Crystal in the manga and suffer little to no consequence; in fact, Sailor Moon was even able to revive the world during the Infinity Arc after Sailor Saturn had to destroy it to stop Pharaoh 90 and Mistress 9. In the anime, the crystal can grant the users' greatest wish if used at full power, but at the price of their life. Queen Serenity, Sailor Moon, and Chibi-Usa have each canonically died at least once while using this ultimate power. Sailor Moon and Chibi-Usa revived due to extraordinary circumstances, but sadly Queen Serenity did not.
 * Tuxedo Kamen gets more to do in the manga, owing to receiving a special attack that allows him to even the odds. For most of the anime, he's stuck with the roses, though they still are pretty dangerous to the target. Just ask Queen Beryl, who received a killing blow with a rose to the heart.

Film

 * In the How to Train Your Dragon, Snotface Snotlout is The Ace and top of the Hooligan's class, as well as Gobber's favorite student. He's a big jerk and a bully to his cousin Hiccup as a result, who . During How to Train Your Dragon's three movies, in contrast, Snotlout is probably the worst student of the Dragon Trainers excluding Hiccup before the latter starts excelling; he's full of braggadocio but can't aim, as a laughing Stormfly noted when he missed hitting her with a mace, and spends more time flirting with the ladies than focused on fighting. Even the twins are relatively better, as it's shown they figured out Stormfly's blind spot and hid it in while arguing. The first TV series showed that he does make up for it with hand-to-hand combat, which he uses to save Hiccup.

Literature

 * A possible interpretation of the story "Cruel Sisters," a take on the Childe Ballad "The Cruel Sister." In the original ballad, Helen killed her younger sister with barely any effort and refused to pull her out before the currents took the princess. Patricia C. Wrede's version has Margaret, the narrator and middle sister, note that while the eldest sister Anne was certainly strong enough to push youngest sister Eleanor in the river, she doubts that it happened. For one, the harp that makes the accusation was made from Eleanor's body, and Eleanor was a liar in life. And for another, Eleanor assumed that they were fighting over a "true bonny" William, where William played with both girls' feelings. Anne also has a habit of not admitting her guilt or innocence to any crime, bearing her punishments with stoicism.

Live-Action TV

 * The Sandman
 * In the comic book The Sandman, Lord Morpheus is pretty powerful even after spending seventy years in captivity. He remakes his Dream palace with a simple gesture, and only needs a few days of bed-rest. In the show, Dream doesn't even get that owing to a hundred years in captivity; he can barely move a few pieces of rubble, and refuses to rest or get food. He has to sacrifice Cain and Abel's gargoyle Gregory to receive enough power to summon the Fates and receive answers about his tools' location.
 * Comic-book Gilbert realized that he couldn't take on the Corinthian after recognizing him, but realized that the latter had . Here, Gilbert doesn't have that opportunity; Corinthian recognizes him at the Empire State Hotel when the latter is helping Rose search for Jed, and is willing to kill . Realizing he has no choice,

Theatre

 * The original film of Beetlejuice had the dead couple Adam and Barbara quickly learn about possession and try it for themselves before soliciting Beetlejuice's help. In the stage play, they are worse at it, so Beetlejuice tries to convince Lydia to summon him instead to ruin her father's party. He also possesses Adam and Barbara to demonstrate his powers, something that didn't happen in the film. Lydia has to interfere by pushing him off the roof-- "What? He's already dead"-- and convince the more trustworthy dead couple to do some possession instead.

Western Animation

 * In the Bunnicula book series, Howard and Chester may have had opposing views on if Bunnicula was evil or not, but they were tough enough to try and either harm Bunnicula (Chester) or save him (Howard). The Bunnicula cartoon turned Howard into a bumbling but well-meaning dog that if anything would solve magical problems by accident, while Chester's Nervous Wreck personality would sometimes cause them.
 * The main character of Superman: The Animated Series (and the DCAU as a whole by extension) compared to the comics. He's still super, but not the crazy levels the character often reaches in his comics.