NoGo

NoGo is a 2005 game by John Moore.

This is a game using the concepts and rules of Go, with some simplifications.

Rules:

• On her turn, the player drops a friendly piece on an empty intersection such that all existing groups of pieces (of either color) have, at least, one liberty (so, no captures or suicides are allowed)
• Wins the last player to move

Black moved last; there is no valid drop left,
so Black wins the match

This is a game that can be analyzed by the tools of Combinatorial Game Theory. The game can be split in a sum of games, when parts of the board no longer interact. For example, using a one-dimensional NoGo, the game o..xxo..xx can be split and simplified by two (in this case equal) subgames: o..x and o..x; this type of property is crucial to computing large game positions.

Moore initially called the game Anti-Atari Go at Sensei's Library. The name No Go meant, back then, another different go variant: After a player has made a move, his opponent may refuse it, and he must make another one. The opponent may not object to this second move (this variant is now known as Forced Takeback Go at Sensei's Library).

There's a ZRF and a Ludii to play the game.