Many authors have examined games that do not satisfy one or more of the conditions on page 1, or have otherwise extended the framework of combinatorial games. No rule is sacred. In this section, Berlekamp introduces a methodology, based on the notion of auctions, to analyze a position in a possibly loopy game, in which play might continue forever. Blackwell relaxes the perfect-information condition. Loeb considers many-player games. Lazarus, Loeb, Propp, and Ullman replace the rule that players have alternate turns by an “auction-based” approach not unlike Berlekamp's. The remaining articles represent significant theoretical advances, while remaining within the traditional framework.