Given the number of awards Holes has won in the field of children's literature, it's pretty much a no-brainer that the book qualifies for that genre. But even if we couldn't figure it out from all those awards, we would probably notice that the book's protagonist is himself a kid. Although we don't actually know how old Stanley is, we can guess from what we hear of his life at home that he's probably in middle school. Not all books with a child as the main character can be classified as children's literature, of course, but this kid-centric, accessible novel is definitely a YA hit.
Holes also features a bunch of plot elements that are common in children's literature: buried treasure, a dangerous journey, and evil, nasty adult characters (check out anything by Roald Dahl for some great examples of that last one). In fact, these same ingredients also qualify the book as an adventure story. While the book can sure be dark at times, and even a little scary, overall it's a fun, exciting read.
In addition to belonging to the children's literature and adventure genres, Holes is also a great example of magical realism. Why do we call it magical realism? Well, let's do a quick run-through and see how some of the book's features do on the handy-dandy Shmoop Realism Test. In order for an element to pass, you have to be able to imagine the characters or events existing within the realm of possibility in the world as we actually know it. Okay, here we go:
We're not sure about you, but here at Shmoop, we don't actually know anyone whose life is being controlled by a century-old family curse. Or, for that matter, anyone who's been saved from certain death by a mountain formation in the shape of a giant thumb. Since most of the book is pretty realistic, though, with just a few not-so-realistic elements thrown in, we can place it squarely in the world of magical realism.