((This version from kirax2 ))
1. Comment in this thread and say, "Fic or Treat!"
2. Tell me who you're dressed as. (You don't have to actually be dressed as that person). You can be any one character from a fandom I know. If I'm not familiar with your character I might--or might not--ask you for a different one. You can be dressed as the same character as someone else, but try to give it a bit of variety if you can (i.e. specify a different version of your character).
3. On October 31st, you'll get a treat! It might be an icon, a song recommendation, maybe even an actual fic or anything else I can think of! Hopefully with a Halloween spin.