- File the serial numbers off. Most authors agree that if someone writes a Buffy fic about Dawn Summers and Spike’s road-trip to Canada, but before they post it they replace “Spike” with “Joe” and “Dawn Summers” with “Tracy” then that author would be legally in the clear*.
- Write only parody. Those fics which criticize cannon, make fun of the characters, or use them to create political satire are legally fine* because they are text-book fair use.
- Write only in public domain worlds. Authors who write fanfiction for Jane Austen, Shakespeare, Mark Twain or Emily Bronte are in the clear because those works are in the public domain and no one has a right to claim copyright over them*.
- Get the author’s personal permission. If your have permission to play in the author’s garden, you can do anything you want.
- Write fics only in worlds where authors have explicitly given broad permission for fans to write in their worlds.
Below’s a silly Venn-Diagram about the legality of copyright–in a shape most copyfighters will recognize as symbolic.
*probably–hard to tell since there’s never been a test-case.
“Borrowing is ubiquitous, inevitable, and, most importantly, good. Contrary to the romantic notion that true genius inheres in creating something completely new, genius is often better described as opening up new meanings on well-trodden themes.”–Chris Springman