Well.I saw this on Fred and George Weasley spot and i don't know whether its done b4.
Game goes like this.I'll write a sentence beginning with TPBM(The Person Below Me).
For eg: TPBM doen't know that Harry is a Half-blood.
Then the person below says true or false and writes another sentence for TPB, o.k.?

Let's start then

TPBM doen't know that Harry is a Half-blood.