A few weeks ago I wrote about children's books that would make great movies, after which I received a flurry of e-mails from people expressing their horror at some of the current adaptations of their favorite childhood tales. I understand -- I've spent twenty years working in children's theater, film and television, and there are times when I look at children's fantasy adaptations and just shake my head. Let's talk about some of the common missteps Hollywood makes in bringing these books to life.

Combining multiple books into a single movie
I don't really understand why Hollywood does this. They find a fantastic property like, say, Lemony Snicket's A Series of Unfortunate Events (2004), and then cram several of the books into a single movie. The problem is that the plot has to be so compressed that you lose almost all character development. Sure the movie is fast-paced, but why should you care? The same thing happens with The Spiderwick Chronicles (2008) although somewhat more successfully. The difference could be that in Spiderwick, the scope remains confined to a single family in a single house, which means there's still time for character development. In Unfortunate Events, the sheer range of characters from the multiple scenic locations deprives any one of them from getting enough screen time.

Being too faithful to the book
What?! Too faithful to the book, you say? Well... yes, it can happen and seems to happen more with children's books that with adult adaptions -- particularly in fantasy. Take The Golden Compass (2007): In an effort to fit every scene from the book into the movie, they wound up with so much material that they had to cut the last three chapters to save for a possible sequel. The trouble is, the pacing that works in a book does not necessarily work well on screen. Consider the first two Harry Potter movies -- which are excruciatingly faithful to the books -- as opposed to the last few that judiciously trim away the fat while retaining the essential sense of the source material.

Going for zany
It's pretty common knowledge that kids will let you know if they are bored. And while there are myriad ways to protect against a theater full of inattentive ankle-biters, movies like Cloudy With a Chance of Meatballs aim for the notion that things must be as Wild! and Zany! as possible. The first part of the 2009 movie is charming -- just like the book -- but then it descends into a flurry of action set-pieces. Another egregious example of this would be 2006's Curious George, which was a series of colorful monkey antics without almost no coherent plot to tie them together. Anyone who has ever sat with a child watching Charlotte's Web will realize that a quiet scene can be plenty engrossing if you're willing to pay attention to clear story-telling and engaging characters.

Forgetting the audience
One of the things I learned from years in children's theater is that there are a bajillion dirty jokes inherent in almost every kid's book. It's tempting to sneak some of those in to keep the grown-ups amused. The problem comes when you forget who your principle audience is. Charlie and the Chocolate Factory (2005) is a fine example of this, presenting the tale with a level of creepiness that scared everyone (adults and children alike) away. As is Cat in the Hat (2003), which went so over-the-top with the adult humor that Theodore Geisel's widow declared there would be no more live-action movies of his work. Way to spoil it for the rest of us, Mike Myers.

Getting excited about the tech
You wouldn't think that Polar Express (2004) and The Seeker (2007) have much in common, would you? But they both get super-excited by their technical effects and forgot that CGI is supposed to support the story-telling, not supplant it. Polar Express's tech takes the form of computer modeling to create characters that almost look alive, the creepiness of which overwhelms the story. (Incidentally, Polar Express' zany factor is also off the charts.) The Seeker is just as egregious in its use of shiny special effects that seem designed to make you forget how thin the plot is. It doesn't work: Part of why we all love fantasy is the magic, but a book about a series of spells isn't enough to entrance a reader, and expecting that to work in a movie is just silly. How do you do this one right? In A Bridge to Terabithia, special effects enhance and support the story and, frequently, are as low tech as throwing pine cones.

What common mistakes in children's fantasy adaptations annoy you? Are there any movies that you think do the job well?

Mary Robinette Kowal is the winner of the 2008 John W. Campbell Award for Best New Writer and a professional puppeteer. Her first novel, Shades of Milk and Honey, is being published by Tor in 2010.