RPGs slowly creeping into preset group templates?

Sometimes called group template, sometimes called social contract, and sometimes called something else entirely. It's the thing you do so the other people at the table know what you want, what you are going for, or how things are going to work around the table. Few, if any, big commercial rpgs talk about them, but some seem to be slipping in rules to make-up for them. Whether it's incidental or not remains to be seen.

I was listening to fear the boot, episode 19, and they were talking about evil characters. Someone brought up that a paladin cannot adventure with anyone less than neutral in alignment. I think that this was inserted, not because of flavor reasons, but because someone knew that the way a paladin works and the way an evil character works, there is bound to be a situation where they disagree and more or less declare war on each other. That is a rule designed to help players with their group template, whether they knew it or not. The other thing is, once you are to the point of actually making a group template, you're prepared to sidestep that rule and handle it on your own.

Then the whole thing got me thinking about the difference between a played game and a written game. The main differences involve your groups playstyle, the players personalities (including the GM), and a few other things that sort of revolve around a group template (whether it's talked about or not). If you create rules that govern the game just like a group template governs play, you'll create a game that is closer to play as written.

Taking a look back on the system I'm creating, there are several of these kinds of rules. A lot of them come from the setting as well. I seem to have stumbled upon a great combination for the type of system I want and the setting that goes with it.