In fantasy and science fiction fandoms, fanfiction is a widespread but controversial phenomenon. Some authors and many fans find fanfictions annoying, for example because of copyright infringement or because they reject such stories as “sacrilege”. Other fans do not reject fanfictions in principle, but are annoyed (usually rightly) by the low quality of many stories or by content that does not match the original work.
On the other hand, it is pointed out that besides the mass of irrelevant and inferior fanfictions, there are definitely well-written stories worth reading, which are positively received by fans and can be an enrichment of the fandom. This lecture offers a brief overview of the history of modern fanfiction and discusses the opinions of J.R.R. Tolkien, Joanne K. Rowling, Marion Zimmer Bradley, Diana Gabaldon, and George R.R. Martin, among others, on the subject of fanfiction. Typical quality problems of fanfiction are also addressed.