A Nomic is a game where one of the objectives, and at the beginning the only one, is changing the rules. The initial rules consist of little more than describing how to change them. They can grow, morph, shrink, and do just about anything that the players want.
This category covers web sites dedicated to Nomics played over e-mail.
Nomic played entirely through a web site (no e-mail lists required) go in Games: Internet: Web: Nomic.