are made of these~
Oh hey! I remember you! XD
Well, keep in mind that I don't have a clue what you're referring to by "Professor Layton", but I'm unsure as to how successful the riddle idea would be. For example, if an RPer or a group was unable to solve one, would they be allowed to ask for help OOC or would their player(s) be... incapacitated, killed off, what? If the riddle's too difficult it may discourage people from posting, but if its too easy then the entertainment is gone. I think it's probably the balance of the riddle which would be most difficult to achieve.