Well, rule one is that you have to be dead--it's the only way to get into the Game. Not long after we die, we're given the option by the Reapers to join in the Game to be given a second chance at life. Obviously, not everyone here is dead and we don't really have a choice whether we can participate or not, so I guess there's two differences.

Rule two is that in order to become a Player in the Game, we have to give up something we hold dear to us.

Rule three is that we have to make a pact with someone so we can fight the Noise and use our psychs with the pins we have. Without a partner, we can't fight. There's a similarity, since we're in teams in this game. I don't know about fighting though.

Rule four: We have 7 days to play, and there's a mission to complete every day. The good thing about that is that if one team completes the mission before the rest of the teams do, all the Players that survived that day pass.

Rule five isn't one that's told, but a lot of the Players find out the hard way--if you're Erased while you're playing the Game, you don't come back. At all. That's why everyone fights so hard to stay alive in the game, even if it means not letting anyone else get ahead of them.