Nomic

Nomic is a game in which the rules of the game include mechanisms for the players to change those rules, usually through a system of democratic voting.

Nomic is a game in which changing the rules is a move. In that respect it differs from almost every other game. The primary activity of Nomic is proposing changes in the rules, debating the wisdom of changing them in that way, voting on the changes, deciding what can and cannot be done afterwards, and doing it. Even this core of the game, of course, can be changed.

—Peter Suber, the creator of Nomic, The Paradox of Self-Amendment, Appendix 3, p. 362.

The game is in some ways modeled on modern government systems, and demonstrates that any rule-changing system can get into a situation in which the laws are contradictory or insufficient to determine what is legal.