Derivative fiction is a genre of fiction that involves writing or reading about or within the worlds of previously established works. People often do not realize it, but many works of classic literature are, in their own ways, derivative fiction of other stories entirely. Dante’s Inferno is a derivative work based on The Bible, for example, but in addition to that, much of Arthurian legend—including all of Sir Lancelot’s legends, and the existence of Sir Lancelot in the first place—comes from derivative works, sometimes even from other countries such as France (which is where Sir Lancelot’s stories all come from). Even Shakespeare’s Romeo and Juliet is based on an Italian play called The Tragical History of Romeus and Juliet, but while the original play framed the deaths of the main characters as caused by their not listening to their parents, Shakespeare changed the ending and other parts of the story to focus on tragic love (Spencer et al.). Even nowadays, derivative works are popular—the superhero comic book industry, for example, is almost entirely derivative fiction, seeing as how almost all comic books nowadays (that are about the big-name superheroes, at least) are written by people who did not create the original characters, showing their own takes on popular figures like Superman, Batman, and Spiderman, and the worlds around them.