I keep hearing, from various podcasts and so forth, about the "social contract" at the game table. It's unfortunate that it's such a common comment, because it's actually a poor model for the activity of playing games. The good news is that I'm not going to bore you with my reasons. It's enough to say that it's a bad choice and that I wish it would go away from talk about playing games.
For further reading, please see the relevant article at the SEP.