Your creations are yours. Your worlds are yours. The only limit to worry about is your own mind's limitations. If, though, you choose to work with already established worlds, please read on.
Avoid writing crossovers or fan fiction unless you can prove that you are allowed to. Different authors have different views about fan fiction. Adding a disclaimer to your story doesn't automatically give you permission to write it.
The following are authors and universes known to expressly PERMIT fan fiction at this time. If you know of others who allow fanfiction, please Master Samak with a link to prove it and it will be added to the following list, which is a non-exhaustive handful of allowable examples:
- Star Trek Paramount actively encourages it
- Buffy Joss Whedon encouraged his fans to read fanfiction to replace the series
- The 1632 Series Eric Flint actively promotes fanfiction and even publishes the fan work of some of his fans.
- Doctor Who / Torchwood The BBC actively encourages fanfiction in non-profit environs.
- Star Wars George Lucas is permissive but he forbids any fanfiction with adult themes. [Since thats not allowed here you are safe there.]
- J.K. Rowling Encourages and even reads Harry Potter fanfiction that is not for profit. Publication, however, she slaps down on hard.
- Runescape Encouraged inside and outside their forums.
[We do encourage you to research, on your own, the up-to-date standing on select fanfiction. Time passes, authors may change their minds, etc. Please, err on the side of consideration.]
Also, for your consideration, the article Make Sure Your Fan Fiction Is Legal (Or Regret It Later)
< Message edited by Master Samak -- 5/19/2020 13:29:06 >