When Steve Kloves (who wrote the majority of the Potter screenplays) met J.K. Rowling for the first time, he told her straight up that Hermione was his favorite character. Rowling admitted to being relieved, and who could blame her? It was more likely for Hermione to end up disrespected on screen—she wouldn’t be the first female hero to get butchered in the reels.
But this resulted in an undercutting of Ron’s entire character from the first movie. Don’t believe it? When the trio go after the Philosopher’s Stone, they face a series of tests that demand each of their skills in turn. Time likely demanded that this sequence be cut down, and so Hermione’s test—solving Professor Snape’s potion riddle—was removed entirely. To make up for this, she gets them out of the Devil’s Snare, Professor Sprout’s deadly plant. Hermione shouts to Harry and Ron to relax so the foliage will release them—but Ron continues to panic and moan (in campiest fashion possible because he’s played by a child actor and these things are always requested of them), requiring Hermione to blast the thing with a sunlight spell.
In the book, Hermione is the one who panics. She remembers what her lessons taught her—that the Devil’s Snare will recoil at fire—but balks at their lack of matches while they are being strangled to death. Ron immediately shrieks to the rescue YOU ARE A WITCH YOU HAVE A WAND YOU KNOW SPELLS WHAT ARE MATCHES.
It’s a simple change, but it makes such a marked difference in how both characters come off to an audience. Rather than a near-infant, incapable of following the clearest directions, Ron is the even-keeled nitty-gritty one. He’s a tactician, the one who will find the simplest answer to a problem provided that the situation is dire enough to ensure his clear head. Ron is good under pressure and brave to boot. He’s also hilarious.
It is easy to write this off as an actor problem; Emma Watson matured and improved much faster than her costars in terms of talent—and Steve Kloves liked her portrayal so much that he started giving her many of Ron’s important lines. During The Prisoner of Azkaban, Sirius Black is trying to get to Peter Pettigrew (currently disguised as Scabbers the Rat), but Ron and Hermione are convinced he’s after Harry. In the book, Ron stares up defiantly from his mangled, broken leg and tells Sirius Black that if he wants Harry, he’ll have to get through his friends first.
Yeah, my leg hurts way too much, Hermione. You take this one. But say it’s from me. And in the film, it’s Hermione who boldly steps in the line of fire while Ron sobs in pain and babbles incoherently.
These rewrites not only depict Ron as an idiot coward—they also make him an outright jerk. When Professor Snape snaps at Hermione yet again for being an insufferable know-it-all, movie-Ron gives her a look and drawls, “He’s right, you know.” Wait, what?! Harry, why are you friends with this prick? Well, maybe because the Ron Weasley that J.K. Rowling put on paper was in that exact same situation, and immediately leapt to Hermione’s defense when she was being abused by a teacher—“You asked us a question and she knows the answer! Why ask if you don’t want to be told?”"
I’ve been indignant about this for years and this makes me even smadder, Of course I adore Hermione, but she’s already wonderful enough without needing to character assassinate Ron to build her up.