I have been thinking of a way to make a forum game that is different from the other ones, which ussually involve doing something to what the person above you has posted, i.e. "ruin their wish" or "banned the game" or "true or false". This game involves coming up with reasons (necessarily real ones) why this topic isn't spam. I don't know how long it will remain enjoyable, but if the game itself turns into spam, I have no problems with it being locked.
