This game is simple. You are re-sorting the characters into a DIFFERENT house than they were in before. So Harry can't go back in Gryffindor, Draco can't go back in Slytherin, etc. You take the character he person above you provided, re-sort them into the house they will most likely be in, then provide another one for the next person. Example:

Imaperson22: Draco

Person2: Gryffindor

Neville

Anotherperson3: Hufflepuff
... Etc.

It can be anyone in the books, from the marauders era to the HP generation to the 19 years later generation and everyone else. If you don't know what house they were originally in, then you can say what house you think they were in. Have fun!

(oh btw if this is already a game on here let me know and I will delete this. I looked and I didn't find anything so I'm assuming this is the first)