So, imagine that you're about to play a relatively standard-ish fantasy game. However, when you sit down to create characters, the world map is blank. What you pick for your race, class, and allegiances? Those choices are directly tied, mechanically, to the group mapping the world with cultural and racial groups, giving them social structures, and creating the politics of the world.Here's an example of what I mean.
So, if you decide to play a Jotunn, you then set up the basics of how the Jotnar are positioned in the world. Later on, if you decide to be a raider, you're also placing "who has raiders, and who do they steal from?". And even later, when the group puts in allegiances, you're all deciding together what the political structures of the world are.
This isn't for a specific game; it's just a proof-of-concept, to see what people think of this manner of handling this thing.
So, er, thoughts?