ruffwriter started a really interesting original fiction challenge here!

It's for prompt-tree format comment fic - you leave a prompt for one thing, and someone else might write a story for that prompt, or might add to your prompt. E.g., you leave a prompt asking for a troupe of hot lady ninjas, and someone else might leave an addition to your prompt adding that the lady ninjas disguise themselves as construction workers by day. Then yet another person could come along and write comment fic for either the original prompt or the ninja/construction workers.

Looks like fun, so come play!