Two players compete in encircling territory on a square board. The board is 19x19 points, but both 9x9 and 13x13 are common as well. Alternating, they move by placing stones of their own colour on empty intersections. Black plays first, then white (except of a handicap game, where black gets additional stones to compensate being the weaker player).
 
If - after a move - any of the opponent's groups have zero liberties the stones of these enemy groups are removed from the board (captured prisoners). A move is illegal if - after any captures - an own group has no liberties.
 
When both players pass successively the game is finished and scored: Neutral points (dame) are filled in, and dead stones are removed. The black and white territory is scored as points surrounded minus the stones captured by the opponent.
 
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