Gomoku Glossary

Whether you're a beginner learning the basics or an experienced player studying professional games, understanding the terminology is essential. This glossary covers all major Gomoku and Renju terms with clear explanations.

Basic Terms

Gomoku (五目並べ)

A strategy board game where two players alternate placing stones, aiming to form an unbroken line of exactly five. The name comes from Japanese: go (五, five) + moku (目, piece). Also known as Five in a Row, Wuziqi (五子棋) in Chinese, and Omok (오목) in Korean.

Renju (連珠)

The professional tournament variant of Gomoku. Renju adds restrictions on the first player (black) to balance the inherent advantage of moving first. Black cannot make double threes, double fours, or overlines. The name means 'connected pearls' in Japanese.

Stone (棋子)

The playing pieces in Gomoku. One player uses black stones, the other uses white. Black always moves first. Once placed on an intersection, stones never move or get removed.

Intersection (交叉点)

The point where two lines on the board cross. Stones are placed on intersections, not in the squares between lines. A standard 15×15 board has 225 intersections.

Stone Patterns

Open Three / Live Three (活三)

Three stones of the same color in an unbroken line with both ends empty. An extremely strong pattern because if not immediately blocked, it becomes an open four (guaranteed win) on the next move.

Broken Three / Jump Three (跳三)

Three stones in a line of four with exactly one gap between them (e.g., ●●_● or ●_●●). Equivalent in threat level to an open three — filling the gap creates an open four. Harder to spot, making it useful for surprise attacks.

Closed Three / Dead Three (眠三)

Three stones in a line where one or both ends are blocked by opponent stones or the board edge. Less threatening than an open three because it can only extend in one direction (or not at all).

Open Four / Live Four (活四)

Four stones in an unbroken line with both ends empty. An unstoppable winning pattern — the opponent cannot block both ends with a single move. Creating an open four essentially wins the game.

Closed Four / Rush Four (冲四)

Four stones in a line where one end is blocked. Still a forcing move (the opponent must block the open end), but not immediately game-winning since the block point is known.

Five in a Row (连五)

The winning condition: five consecutive stones of the same color in a horizontal, vertical, or diagonal line. In standard Gomoku, six or more also wins. In Renju, an overline by black is forbidden.

Overline (长连)

Six or more stones in an unbroken line. In standard Gomoku, this counts as a win. In Renju, an overline by black is a forbidden move — black must form exactly five, not more.

Tactics & Techniques

Fork / Double Threat (做杀)

A single move that creates two simultaneous winning threats (usually two open threes, or an open three and a four). Since the opponent can only block one threat per turn, a fork guarantees a win. Creating forks is the primary offensive goal in Gomoku.

VCF (Victory by Continuous Fours)

A winning technique that uses a sequence of consecutive four-in-a-row threats. Each four forces the opponent to block, and the attacker continues with another four. If a VCF sequence exists, the win is guaranteed regardless of the opponent's play.

VCT (Victory by Continuous Threats)

A broader winning technique that chains both fours and open threes in sequence. More complex than VCF because the opponent may have multiple response options to threes. Finding VCT sequences is a key skill for advanced players.

Tempo (先手)

The initiative in the game — having tempo means your opponent is forced to respond to your threats rather than building their own. Maintaining tempo is crucial: each forcing move (like creating a three) keeps the initiative in your hands.

Ladder (追子)

A tactical sequence of consecutive fours that forces the opponent to block in a predictable direction, leading to a pre-set winning position. Setting up a successful ladder requires reading many moves ahead.

Sente (先手) / Gote (後手)

Borrowed from Go terminology. Sente means having the initiative — your move forces a response. Gote means being reactive — you're responding to your opponent's threats. Good play aims to maintain sente as much as possible.

Renju-Specific Terms

Forbidden Move (禁手)

In Renju, certain moves are illegal for black: double three, double four, and overline. If black plays a forbidden move, black loses immediately. These rules exist to balance the significant first-move advantage.

Double Three (三三禁手)

A move that simultaneously creates two open threes. In Renju, this is forbidden for black. It's one of the three forbidden patterns designed to limit black's first-move advantage.

Double Four (四四禁手)

A move that simultaneously creates two fours (open or closed). Forbidden for black in Renju. Even a closed four plus an open four counts as a double four violation.

Board & Setup

Board Size

Gomoku can be played on various board sizes. The standard tournament size is 15×15 (225 intersections). Smaller boards (9×9, 11×11) lead to faster games with less strategic depth. Larger boards (19×19, shared with Go) offer more complex play but longer games.

Opening (布局)

The first few moves of a Gomoku game. In Renju, openings are formally classified and named. Famous openings include Flower Moon (花月), Cold Star (寒星), Rain Moon (雨月), and Pine Moon (松月). Each opening leads to different strategic positions.

Swap Rule / Swap2

A fairness rule used in tournaments. After the first player places one or more opening stones, the second player can choose to swap colors. This discourages overly aggressive openings and helps balance the first-move advantage.

Tsumego (詰碁)

Practice puzzles where you must find the winning move or sequence in a given board position. Originally a Go term, but widely used in Gomoku/Renju training. Solving tsumego improves tactical reading ability.