I love the Harry Potter films. I have dear friends who worked on them. I was on the set during the filming of Order of the Phoenix. David Heyman even told me that they used the Lexicon “every day” while they created the films. So don’t mistake what I’m about to say for anything but loving criticism.

The films are nothing more than very expensive fan fiction. They’re made-up stories closely based on the Harry Potter books, created by people who are massive Harry Potter fans and who care very deeply about “getting it right,” but who, for one reason or another, changed a lot of things. Sometimes they changed things for very good reasons. Sometimes, though, they seem to have changed things for no particular reason at all. I can’t explain it, but there you go.

However, for a lot of people, the films are Harry Potter. They’ve never read the books, or barely read them anyway. As far as they’re concerned, Dementors attacked Harry and Dudley in an underpass below a highway. Snape died in a boathouse. And Harry fought Voldemort in an extended, violent duel at the end of the Battle of Hogwarts, punctuated by clever bon mots and death-defying falls from high places.

But oh well. I really don’t care. At least they’re Potter fans! The more the merrier! Just do me a favor … don’t send me any more emails telling me that I screwed up on the Lexicon when I write that:

1 – James was a Chaser. Yes, I realize that in the books James plays with a Snitch. Yes, I realize that the first film shows that weird Quidditch shield which says that James was a Seeker. Seriously, the year on that shield makes no sense and there’s an M. McGonagall on there too! Yeah … no. But Rowling herself said that James was a Chaser (Sch2). Maybe she misspoke herself, maybe she meant to say Seeker, but she didn’t. She said Chaser. So until she tells us otherwise, that’s what we’re putting in the Lexicon.

2 – Neville went into the Forest for detention in the first book, not Ron. In the book, Ron is in the Hospital Wing when Harry and Hermione take Norbert up to the top of the Astronomy Tower and hand him off to Charlie’s friends (PS15). Why Neville then? Because he left Gryffindor Tower that night, trying to stop Harry and Hermione from doing whatever it was they were planning to do, and he got caught.

3 – Harry Potter and his friends didn’t wear British-style school uniforms to Hogwarts. They wore robes. They wore things like jeans under their robes, sure. But they definitely wore robes. And I’m not talking about capes, either, I’m talking about full-blown robes. With pockets for wands and things. No school ties, no sweaters (except Weasley ones at Christmas; PS12), no shirttails hanging out, nothing. Oh, and they wore black pointed hats.

4 – Death Eaters didn’t fly through the air like jets of smoke. According to Rowling, “No spell yet devised enables wizards to fly unaided in human form” (QA1). When Voldemort figured out how to do it in book seven (DH5), everyone was completely blown away. And the only person Voldemort taught how to do it was Snape (DH30). They’re both dead, so that leaves no one who knows how to fly. It does look cool in the films, though.

5 – It’s pronounced VoldeMORE, not VoldeMORT. Rowling herself said so: “I say ‘Voldemor’ but I’m the only one.” No, you’re not, Jo! Lots of fans say VoldeMORE. Jim Dale even said VoldeMORE in the audio versions of the first few books. Sadly, after the first film came out with everyone pronouncing it wrong, Jim Dale started saying it wrong too. Looks like they got to him, doesn’t it.

6 – There is no such thing as a Lumos Maxima spell. There’s only Lumos. If there had been some powerful light spell that could generate solar-level beams of light, don’t you think Dumbledore would have used it to look for Barty Crouch Sr. on the grounds in book four? No, he used the same feeble little Lumos spell everyone else uses (GF28). Lumos Maxima, like most of the spells in the film, is not canon. So there’s no Bombarda, no Bracchium Emendo, no Fera Verto, and no Immobilus. And Finite Incantatem won’t stop a Bludger. It stops spells … that’s what Finite Incantatem means in Latin. But, as Rowling said when asked about the illogical spells invented by the filmmakers, “That’s showbiz!”

There are more, sure. But those are the ones that seem to generate the most email. What film errors drive you crazy?