14-15 & up I believe is the best age range to read this book & the others that go with it. It has the same amount of violence as a PG13 movie! It's just a book & if you taught your kids right from wrong, real & not real then there shouldn't be an issue if they read this book.
There is some violence in them yet parents let their kids watch those movies (that isn't Rated R), there are PG13 movies like Spider-Man, Avengers, etc that has some violence in them but, it's no different than reading this book. Also, look all the movies that are out there. I just don't understand why parents are bashing this book when there are far more serious issues going on in this world. even though it's found in the Young Adult section. This book does state that it's for ALL ages somewhere in the first few pages, I think where the Copyright & list of other books are. I love to read & will read just about anything that catches my eye.