Adaptational Personality Adjustment

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

Then it hits you; their personalities are different! They like various things or behave in a manner contrary to the source.

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

Film

 * How to Train Your Dragon (animation): This pretty much goes for any major character when making comparisons to the original source material:
 * Book Hiccup is a quiet, bookish dragon nerd kid that only snarks occasionally, while book Fishlegs spends his time snarking at the stupidity of the adults around them that are in charge of their lives. The film and franchise erverse their personalities where movie Fishlegs is the bookish dragon nerd kid and Hiccup is the Deadpan Snarker.
 * Book Toothless was a bratty housecat with wings. He spends most of his screen-time refusing to obey Hiccup, coercing fish and treats from him. Movie Toothless is more akin to a panther, and closer to Hiccup's riding dragon Windwalker as well as his elder companion The Wodensfang ; he is a deadly predator that never misses, but also willing to train Hiccup as much as Hiccup trains him.

Live-Action TV

 * Pretty Guardian Sailor Moon did this quite a bit:
 * Ami, in addition to her genius nature, is given No Social Skills to boot and a fear that her friends will leave her..
 * Princess Serenity, unlike the manga, isn't a carbon copy of . The first hint is actually that . Far from the sweet-natured princess that would sneak out to see Prince Endymion, this Princess Serenity is revealed to be.
 * The never-released ToonMakers pilot of Sailor Moon featured this. Rather than Usagi an ordinary, ditzy teenage girl that happens to be a reincarnation for a Sailor Guardian, "Vicky" is the cover for Princess Sailor Moon after she and her friends escape from Beryl when they flee the Moon Kingdom, on Sailor Moon's wedding day no less. She hides sadness about leaving her home, her fiance Earth Prince Darien and her mother behind a smiling exterior and a desire for normal teenage girl things like dances and cosmetics. The other Senshi follow suit: Sailor Mars is a lot mellower than her original counterpart, asking her friends for fashion advice; Sailor Mercury loses the computer and her genius; Sailor Jupiter is more motherly; and Sailor Venus is less of a ditz, showing that she is a serious warrior in battle and a Handicapped Badass to boot.

Puppet Shows

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

Western Animation

 * Discussed in-universe during Avatar: The Last Airbender when the Gaang sees "The Ember Island Players". Aang complains that the bald woman portraying him shows a mischievous Avatar that can't resist playing jokes on his friends. Katara becomes prone to tears, Sokka is obsessed with food, Iroh is a Lazy Bum and so forth. Zuko, despite his protests to the contrary, is probably the most accurate in the Ember Island show, as he is dark and brooding and goes, "How can you say that?!" dramatically. Katara smirks when the actor proves her point.