Board & Pieces
Goban
The board. Standard size is 19x19 lines (361 intersections). Smaller boards (9x9, 13x13) are used for learning and quick games.
Intersection
Stones are placed on the points where lines cross, not inside squares. A 19x19 board has 361 intersections.
Star Points (Hoshi)
The nine marked intersections on a 19x19 board used as visual reference points and for handicap stone placement.
Tengen
The center point of the board (10-10 on a 19x19). Rarely played in professional games; considered strategically low-value as a first move.
Komoku
The 3-4 point corner intersection. A common opening stone placement balancing corner control and influence toward the center.
Handicap Stones
Extra stones given to the weaker player before the game starts, placed on star points. Each stone represents roughly one rank of strength.
Core Concepts
Liberty
An empty intersection directly adjacent (not diagonal) to a stone or group. A group with zero liberties is captured and removed from the board.
Group
A set of connected stones of the same color. Stones are connected when they are directly adjacent horizontally or vertically.
Capture
Removing an opponent's stone or group from the board by surrounding it completely, leaving it with no liberties.
Atari
A group reduced to exactly one liberty. The opponent can capture it on the next move unless the player escapes or adds liberties.
Ko
A rule preventing immediate board repetition. After capturing a single stone that would recreate the previous board position, the opponent must play elsewhere before recapturing.
Suicide Rule
Placing a stone that immediately reduces your own group to zero liberties (without capturing) is illegal in most rulesets.
Territory
Empty intersections completely surrounded by one player's stones. Counted at the end of the game as points.
Komi
Bonus points added to White's score to compensate for Black's first-move advantage. Standard komi is 6.5 or 7.5 points depending on ruleset.
Life, Death & Shape
Eyes
Empty intersections completely enclosed within a group. A group with two separate eyes cannot be captured because filling either eye would be suicide for the opponent.
Two Eyes (Life)
A group with two separate internal eyes is unconditionally alive and cannot be captured under normal rules.
False Eye
An apparent eye that can be filled by the opponent without it being suicide. A group with only one real eye and one false eye is dead.
Seki
Mutual life. Two opposing groups share liberties such that neither player can attack without losing their own group. Neither group is captured; neither scores the shared space.
Snapback
A tactical sequence where capturing one stone leads to a larger group being captured on the very next move.
Ladder (Shicho)
A capture sequence where a stone in atari is chased across the board in a zigzag pattern. The chase fails if the ladder hits a friendly stone.
Net (Geta)
A shape that surrounds an opponent's stone at a distance, preventing escape in any direction without immediate capture.
Strategy & Openings
Fuseki
The opening phase of the game. Stones are placed across the board to claim corners, sides, and influence before close fighting begins.
Joseki
Established, locally balanced sequences of play in the corners. Considered equal outcome for both players when played correctly.
Influence
Stones positioned toward the center to project power outward, used to build territory or support future fights rather than directly claiming space.
Moyo
A large framework of potential territory. Not yet secure territory, but a formation the opponent must invade or reduce.
Thickness (Atsumi)
A solidly built group with no weaknesses, used to project influence and support stones elsewhere on the board.
Sente / Gote
Sente: a move that demands a response, keeping the initiative. Gote: a move that surrenders the initiative. Maintaining sente is a core strategic principle.
Tenuki
Ignoring the local position and playing elsewhere. A calculated decision that the rest of the board is more urgent than responding.
Tesuji
A skillful tactical move, often surprising, that solves a local problem efficiently. The Go equivalent of a chess combination.
Endgame & Scoring
Yose
The endgame. After the main fighting, players fill boundaries between territories. Large yose moves can decide close games.
Dame
Neutral points that belong to neither player, filled at the end without scoring. Also used informally to mean a useless or wasted move.
Prisoners
Stones captured during the game. Under territory scoring, prisoners are subtracted from the capturing player's territory count.
Resign
Conceding the game before scoring. Common in professional play once the outcome is clear; considered good sportsmanship when a loss is certain.