I'm writing a college research paper on fanfiction and one of the sections is going to be "When Not to Write Fanfiction." I know several authors have come out and stated that they do not want to have people use their characters in fanfiction writings (i.e. Anne Rice and Anne McCaffrey). Could you please tell me your opinion on people using your characters in fanfiction stories for personal enjoyment?
The time to write fan fiction is "never."
You will never do your best work in someone else's universe, because you're bound by their rules. Furthermore, most universes that people use for fan fiction are dreadfully dumb - one thinks of Star Trek and Star Wars - and most seventh-graders can come up with better ones.
As for using characters created by another author: That's where you're going to find yourself sued by any author who understands where the financial future of his work lies. In order to protect copyright and potential filmmaking rights, you have to AGGRESSIVELY protect your own authorship of characters, precisely because it is the characters that film companies need to license and protect when your work is filmed. Anybody writing fiction using my characters without my specifically having licensed it to them will be sued, not because I'm mean and selfish, but because this is the INHERITANCE OF MY CHILDREN, and to write fiction using my characters is morally identical to moving into my house without invitation and throwing out my family.
I care very much about new writers, which is why I strongly urge them never, never, never to waste their time writing stories set in other writers' universes without specific invitation, and even then they'd do more for their careers by spending their time inventing their own worlds and creating their own characters. Piggy-backing on someone else's financial success isn't how you create a career, and the "experience" you gain is worthless, since you steal precisely those story elements that you must invent for yourself in order to learn how to create workable original fiction.