This is a role-playing game, but an unusual one. The focus is on telling stories, and to facilitiate this, instead of having a traditional Game Master/Player split, all players can contribute to the game, and can create rules, called Gimmicks. (Also, a Gimmick is a form of Tenet, which is also somewhat like a rule in Nomic.)
What you can or can't do to modify the world of the story -- or to modify the system that runs the game -- is moderated with a currency system, based on Coins. Such a currency system might make an interesting addition to a game of Nomic, and Universalis is worth checking out for that fact alone, even if you have no interest in role-playing games.
You can get more information and a sample chapter at the web site: 
http://universalis.actionroll.com