Scoring Example another liberty at D. It would be suicidal (and hence illegal) for white to play at E, The board is initially because the block of four white empty. stones would have no liberties. Could black play at E? It looks like a suicidal move, because Black plays first. the black stone would have no liberties, but it would occupy On a turn, either place a the white block’s last liberty at stone on a vacant inter- the same time; the move is legal and the white stones are section or pass (giving a captured. stone to the opponent to The black block F can never be keep as a prisoner). In the diagram above, white captured. It has two internal has 8 points in the center and liberties (eyes) at the points Stones may be captured 7 points at the upper right. marked G. To capture the by tightly surrounding Two white stones (shown be- block, white would have to oc- low the board) are prisoners. cupy both of them, but either them. Captured stones White’s score is 8 + 7 − 2 = 13. move would be suicidal and are taken off the board Black has 3 points at the up- therefore illegal. and kept as prisoners. per left and 9 at the lower Suppose white plays at H, cap- right. One black stone is a turing the black stone at I. prisoner. Black’s score is (Notice that H is not an eye.) It is illegal to make a − 3 + 9 1 = 11. White wins. Black is not allowed to play suicidal move. Capturing Examples back at I, recapturing the white stone, because if this It is illegal to repeat a were allowed it could go back F F F F board position. (This is and forth forever. The ko rule G F G F says that a full board position the ko rule). F F F H can never be repeated. Black I could recapture at I on a later Play continues until both turn after something had players have passed con- changed elsewhere on the board. secutively and white has A A B C C Technicalities passed last. You can ignore these until E A D you’ve played a few games. At the end of the game, Stones are captured in blocks score one point for each of one or more stones. A block The full board is 19x19, com- is a contiguous group of stones pared with the 9x9 board intersection you have connected along the lines on shown here. surrounded, minus one the board; diagonals don’t White is given 7.5 extra point for each of your count. In the diagram above, points, called komi, as com- the three stones marked A pensation for having to move stones held prisoner. The form a block. second. high score wins. A block is captured when there Between players of uneven are no empty intersections strength, black is given some (called liberties) next to it. These are the American Go Asso- extra stones on the board at Block A has one liberty, at B. ciation rules. Rules vary slightly the beginning of the game. In If black plays at B, the three from one country to another. See such handicap games, white white stones are removed. The www.usgo.org for more informa- plays first and komi is reduced two stones labeled C are not tion. to 0.5 (so white wins ties). captured, because they have