Forum game idea

I saw @MC_Scout his puzzle on the forums, and I thought it'd be cool to make a 'riddle forum game'. However, I don't know how to make a very funny game from this concept.

I won't be making any threads without some sort of quality, so I'd like you to give some ideas on how to make this an actual forum game, that'll be in the list for very long. You may also start an own game, but if you came to the idea of doing something with riddles after reading this thread, please mention me! ^^