It doesn't take a genius to figure out that Harry Potter was based on Harry Potter, and Lord of the Rings was based on Lord of the Rings. But some film adaptions of books stray a little further from their source material, and change not just the plot or characters, but the very title of the work itself.
Which is why we've decided to quiz you. Sure, you claim to be a massive Die Hard fan, but do you know its inspiration? Are you clueless about the literary genius behind Clueless? And just what William Shakespeare works could be responsible for some of cinema's grandest tales?
Match the following films to their original novels for your chance to feel sort of good about yourself.