I’m going to see Mortal Engines this week, based on the eponymous book.

In the novel, the main heroine has an ugly scar across her entire face, and a chunk of her character development is learning that there are people who will accept her despite her appearance. In the film, her face is fine and the scar is cosmetic. Some fans got upset over the change, signed a petition, and even got a reply out of Peter Jackson.

Truth is, you cannot have the protagonist of a movie be physically repulsive, unless you make the entire movie about them overcoming that disability (and probably make the movie low-budget). A book can do mutilated characters, because when I read a book, I can be analytical: there is no moment of instinctive recoiling that I feel when I see on a person with a destroyed face in front of me.

There is a gap between how I wish I felt about people based on their appearance, and how I do feel. And while many people in Hollywood are interested in softening the prejudice against deformity and mutilation, in the end the decision to make an expensive movie like Mortal Engines rests with the people who will be risking their money on a film. The movie must recoup its cost whatever its genre or message.

You can’t judge a movie the same way you judge a book.