Copyright (c) 1990 Fred Horn

The game starts on an empty Go board. There are enough 2x1 stones (like dominoes) of two colors.

  • CELL CONTROL - A cell is controlled by a player if that cell is empty and is orthogonally adjacent only to, at least, one of that player's stones.
    • This means that any empty cell not adjacent to any stone or adjacent to both player's stones, is not controlled by anyone.
  • TURN - A player drops a friendly stone on two orthogonal adjacent empty cells provided that those are not (orthogonally or diagonally) adjacent to any other piece (of either color).
  • GOAL - The player that controls more cells wins the game.


In this diagram (using a 9x9 sample board) we see some of the cells controlled by each player. Notice, however, that only cells a7, a5 and g5 are permanently controlled.