The rules of Chomp are simple. Players alternate turns, on each turn removing a square, as well as all those that are above or the the right of it (in other words, all squares with both coordinates ≥ it). The goal is to avoid having to eat the poison square (the one with the skull on it).

these are the three final move options. The option with the highest average probability will be selected as Manifold's move and will resolve to YES if Manifold wins and NO if Manifold loses. The others will be resolved N/A. In other words, each of these can be thought of as conditional markets for Manifold winning, given that each move is chosen.