They put enough detail into the movie that someone who has not read the book would be able to follow along with the story and really grasp the depth of what is happening. For someone who has read the books, they were able to keep enough of the story to leave you satisfied and not like you were somehow cheated. They did definitely change some things and I wish to a degree they could have gone further into depth but when the movie is already 2.5 hours you can't really do that. As someone who has read the books, I enjoyed the movie. My dad who went with me and has not read the books also enjoyed it.