As opposed to, what colour is the sky in your world? Although I suppose that could be quite the unexpected tweak. 
Copied over from the EZboard forums.
How much do you tweak your campaign world? Even if you use a purposefully generic setting like FR or Greyhawk, do you allow everything that's in the various sourcebooks, no matter how outre it is (alienist, oozemaster, etc)? Do you go to the trouble of creating special groups, knightly orders, mages' guilds etc, and if so, do you make up prestige classes to go with these?
I guess I want to see how much of an active "editorial stance" people take. On the one hand, you have groups where anything that sounds interesting and isn't too unbalanced is okay. On the other hand, you have groups that have a highly specific idea of what they want in the game world, and anything that doesn't fit the vision is rejected.
Any comments, people?

Copied over from the EZboard forums.
How much do you tweak your campaign world? Even if you use a purposefully generic setting like FR or Greyhawk, do you allow everything that's in the various sourcebooks, no matter how outre it is (alienist, oozemaster, etc)? Do you go to the trouble of creating special groups, knightly orders, mages' guilds etc, and if so, do you make up prestige classes to go with these?
I guess I want to see how much of an active "editorial stance" people take. On the one hand, you have groups where anything that sounds interesting and isn't too unbalanced is okay. On the other hand, you have groups that have a highly specific idea of what they want in the game world, and anything that doesn't fit the vision is rejected.
Any comments, people?