Bidding combinatorial games

Combinatorial Game Theory is a branch of mathematics and theoretical com-puter science that studies sequential 2-player games with perfect information. Normal play is the convention where a player who cannot move loses. Here, we generalize the classical alternating normal play to infinitely many game families, by means of discrete Richman auctions (Develin et al. 2010, Larsson et al. 2021, Lazarus et al. 1996). We generalize the notion of a perfect play outcome and find an exact characterization of outcome feasibility. As a main result, we prove the existence of a game form for each such outcome class; then we describe their lattice structures. By imposing restrictions to the general families, such as impartial and symmetric termination, we find surprising analogies with alternating play.