Game Start: Black moves first, White moves second. Stones are placed on the board's intersections by clicking them; press 'Space' to pass your turn.
Stone Movement: Stones do not move after being placed—they stay put unless captured.
Capturing Stones: Stones are captured when they are completely surrounded on all four sides (up/down/left/right) by opponent stones = they have zero liberties.
Liberties: Empty intersections surrounding the stone: zero liberties = capture.
No Suicide: You cannot place a stone where it would have no liberties unless it captures an opponent stone in the process.
Groups: Stones connected in the horizontal or vertical direction (not diagonal) are considered a group. Groups share liberties and are captured all at once.
Ko: You cannot make a move that would recreate the exact same board position as the turn before (this is prevented automatically).
Territory: Control more territory (empty spaces surrounded by your stones only) than your opponent by the end of the game.
Scoring: Your territory + the number of enemy stones you captured = your score. The player with a higher score wins.
Passing: When both players pass their turn consecutively, the game ends.