Gomoku Glossary: Key Terms and Definitions A–Z

How to Use This Glossary

This glossary covers the most important terms used in Gomoku and Renju discussion, commentary, and instruction. Terms are organized alphabetically. Where a term has a Japanese, Chinese, or Korean equivalent that is commonly used in English-language resources, it is noted.

A

Adjacent — Directly next to another stone horizontally, vertically, or diagonally with no gap between them.

Alive — Describes a formation that has at least one open end and can still be extended to five.

B

Black — The player who moves first. In Renju, Black faces additional restrictions to offset the first-move advantage.

Block — To place a stone next to an opponent’s line to prevent it from extending to five.

Broken three — A three-stone formation with exactly one internal gap (e.g., XX_X or X_XX). Also called a split three or jump three.

C

Capture — Not part of standard Gomoku, but present in Pente, where a pair of opponent stones flanked on both sides is removed from the board.

Closed four — A line of four consecutive same-color stones where one end is blocked by an opponent’s stone or the board edge. The open end must be blocked to prevent a win.

Continuous attack — A sequence of forcing moves (threats) played one after another without giving the opponent a chance to counter-attack.

D

Dead — Describes a formation that can no longer be extended to five, typically because both ends are blocked.

Diagonal — One of the two slanted directions on the board (upper-left to lower-right, or lower-left to upper-right).

Double four — A move that creates two separate fours simultaneously. In Renju, this is a foul for Black.

Double three — A move that creates two separate open threes simultaneously. In Renju, this is a foul for Black.

E–F

Endpoint — An empty intersection at either end of a stone line where the next stone could extend the formation.

Five — The winning formation: exactly five consecutive same-color stones in a line.

Forcing move — A move that compels the opponent to respond immediately, typically by creating a four or an open three.

Four — A line of four consecutive same-color stones. Can be open (both ends available) or closed (one end blocked).

Foul — In Renju, an illegal move by Black, including double three, double four, and overline. Making a foul means Black loses the game.

Freestyle — The basic Gomoku rule set with no restrictions on either player. Also called free Gomoku.

G–H

Gobang — An older European name for Gomoku, sometimes spelled “Go-bang.”

Gomoku — The full game of five-in-a-row played on a 15×15 or 19×19 grid. From the Japanese 五目 (gomoku), meaning “five points.”

Gomoku Narabe — The full Japanese name for the game, meaning “five points line up.”

Half-open — A formation with one end open and one end blocked. Synonymous with “closed” in most contexts.

I–J

Initiative — Having the ability to dictate the flow of play through threats. The player with initiative forces the opponent to respond.

Intersection — The point where two grid lines cross. Stones are placed on intersections, not in the squares.

K–L

Ladder — A sequence of forced moves that pushes a threatened line across the board diagonally or in a straight path, similar in concept to a ladder in Go.

Line — Any row of consecutive same-color stones on the board — horizontal, vertical, or diagonal.

M–O

Narabe — Japanese for “line up” or “arrange in a row.” Used in the full name Gomoku Narabe.

Offset opening — An opening where the first stone is not placed on the center point.

Omok — The Korean name for Gomoku (오목), meaning “five stones.”

Open four — A line of four consecutive same-color stones with both ends empty. This is an immediate winning threat because the opponent cannot block both endpoints.

Open three — A line of three consecutive same-color stones with both ends empty. A dangerous formation because it can become an open four in one move.

Overline — A row of six or more consecutive same-color stones. In freestyle Gomoku, an overline counts as a win. In Renju, an overline by Black is a foul and loses the game.

P–R

Pair — Two consecutive same-color stones, also called a two.

Pente — A Gomoku variant invented in 1977 that adds capturing mechanics.

RIF — The Renju International Federation, founded in 1988 to govern competitive Renju and Gomoku.

Renju — A variant of Gomoku with restrictions on Black (no double three, double four, or overline) to balance the first-move advantage. From the Japanese 連珠 meaning “connected pearls.”

S

Split three — See “broken three.”

Standard opening — An opening protocol prescribed by tournament rules, often involving swap or swap2 to ensure fairness.

Swap rule — After Black’s first move, White may choose to swap colors instead of placing a stone.

Swap2 — An opening protocol where Black places two black stones and one white stone, then White chooses which color to play.

T

Tempo — The concept of initiative in terms of moves. Gaining tempo means your opponent must respond to your threat, giving you an extra effective move.

Threat — Any move that creates the possibility of completing five in a row if not answered.

Three — A line of three consecutive same-color stones. Can be open, closed, or broken.

Two — A line of two consecutive same-color stones.

V–W

VCF — Victory by Continuous Fours. A winning sequence where every move creates a four, forcing a block each time, until five in a row is achieved.

VCT — Victory by Continuous Threats. A broader winning strategy where every move creates a threat (not necessarily a four), leading to an unavoidable five.

White — The second player. In Renju, White plays without restrictions.

Wǔzǐqí — The Chinese name for Gomoku (五子棋), meaning “five-stone chess.”

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