Board Thread:Off Topic/@comment-26025032-20151118050700/@comment-25396609-20151118051815

It is illegal to sell a derivative work of copyrighted material without permission of the copyright holder.

If you write RWBY fanfic and try to sell it I will personally see to it RT know and can take legal action.

However if you're ONLY writing it and distributing it freely, that's completely legal.