When comparing popular books and their film adaptations, it will be next to impossible to not spot the differences between the two. As a book aficionado, it's sometimes hard trying to ignore any changes, minor or major, made in the final cut of the film; when it leans on the drastic side of the spectrum, this can either hurt the movie or help distinguish the film from the franchise it is based on. Keeping this major spoiler warning in mind, here are a few books and their film adaptations that are known for the vast changes made.
As far as famous books and their film adaptations go, The Hunger Games series has been criticized for the important details cut out, which inadvertently warped the history. To be specific, I know that I don't speak alone in saying that making the decision to strip away the meaning of the mockingjay pin and its origin by eradicating the background story behind how Katniss got it was very upsetting. While I love The Hunger Games franchise (both the films and books as a whole), I feel that this move changed certain dynamics.