Gomoku Glossary: Complete A-Z of Terms and Definitions
The complete gomoku glossary — every term you will meet in the game, from basic shapes like the open three to Renju’s forbidden moves and the 26 designated openings. Each entry has a clear definition, the Chinese and Japanese names where they exist, and a link to the page where the concept is explained in depth. Use this as your reference, and as a hub: every term here is an anchor other articles link back to.
10 Must-Know Terms
If you are new to gomoku, start here. These ten concepts cover roughly 80% of what you need to understand the game and follow strategy guides.
A–Z Index
Shapes & Patterns
The fundamental stone configurations — the vocabulary of every gomoku position.
Open Two 活二 · 活二
Two stones in a row with both ends open. The foundational building block — weak on its own, but it can develop into an open three, so strong players create and combines them to build pressure.
Open Three 活三 · 活三
Three stones in a row with both ends open. It can become an open four on the next move, so the opponent must respond immediately or lose. One of the most important forcing shapes.
The red-ringed stone is the move that creates the shape.
Open Four 活四 · 活四
Four stones in a row with both ends open. Unblockable — the opponent can cover only one end, so you complete five on the other. An open four is a winning threat.
The red-ringed stone is the move that creates the shape.
Closed Three 眠三 · 眠三
Three in a row with one or both ends blocked. Less flexible than an open three and slower to develop, but it can still become a closed four and create forcing threats.
Closed Four 冲四 · 冲四
Four in a row with one end blocked. Still a forcing move (the opponent must block the open end), but easier to defend than an open four since there is only one winning point to cover.
The red-ringed stone is the move that creates the shape.
Overline 长连 · 長連
A line of six or more stones. In standard gomoku it is not a win (exactly five is required); in free-style it counts as a win; in Renju it is a forbidden move for Black.
The red-ringed stone is the move that creates the shape.
Double-Three 双三 · 三三
A single move that creates two open threes at the same time. The opponent can block only one, so the other becomes an open four. Forbidden for Black in Renju because it is an unstoppable double threat.
The red-ringed stone is the move that creates the shape.
Double-Four 双四 · 四四
A single move that creates two fours at the same time. Each four threatens to complete to five, and the opponent can block only one. Forbidden for Black in Renju.
The red-ringed stone is the move that creates the shape.
Four-Three 四三 · 四三
A single move that creates a four and an open three at the same time. Unlike double-three and double-four, this is legal in Renju and is one of the most powerful winning tactics — the four forces a block, then the three becomes an open four.
The red-ringed stone is the move that creates the shape.
Split Three 跳三 · 跳び三
Three stones with a gap (such as X-XX or XX-X) that can still become an open four by filling the gap. It functions like an open three — the opponent must respond or be overrun.
Empty Triangle 空三角 · 空き三角
Three stones forming a triangle with one empty intersection in the middle. An inefficient shape that wastes a stone; generally avoided because the same stones in a line would be stronger.
Five in a Row (pattern) 五连 · 五連
The winning pattern: an unbroken line of exactly five stones, horizontal, vertical, or diagonal. Not six, not four — exactly five. The entire object of the game.
The red-ringed stone is the move that creates the shape.
Tactics
How shapes combine into plans: forcing sequences, calculation, and the double threat.
Forcing Move 先手 · 先手
A move the opponent must respond to immediately — typically a four (which threatens five) or an open three (which threatens an open four). Forcing moves let you control the tempo and build winning sequences.
VCF 连续冲四胜 · 連続四
Victory by Continuous Four — a sequence of forcing fours that leads to an unavoidable win. Calculating VCFs deep into the game tree is a core intermediate skill and the most common way games are won at club level.
VCT 连续活三胜 · 連続三
Victory by Continuous Threat — like VCF but using open threes as the primary weapon. Harder to calculate than VCF because open threes offer the opponent more defensive choices.
Double Threat / Fork 双打 · 両狙い
A move that creates two threats at once, so the opponent can block only one. The basis of most winning combinations — double-threes, double-fours, and four-threes are all forms of double threat.
Tempo 步调 · 手番
The initiative — having the opponent respond to your moves rather than pursue their own plan. Gaining tempo means dictating the sequence, which is usually decisive.
Setup Move 做杀 · 待ち手
A quiet move that prepares a future forcing sequence without creating an immediate threat. Setup moves are how strong players convert a positional edge into a calculable win.
Threat Tree 威胁树 · 読み
The branching sequence of forcing moves and opponent responses a player calculates mentally. Building and evaluating threat trees is the core of gomoku calculation.
Block 挡 · 受け
A defensive move that stops the opponent’s line from extending. The fundamental defensive response — but against a double threat, a single block is not enough.
Openings
The structured first moves of tournament Renju and the rules that govern them.
Direct Opening 直指 · 直指
An opening where Black’s second stone is placed directly adjacent to the first. The 13 direct openings are the odd-numbered entries (1, 3, 5, … 25) in the 26-opening canon.
Indirect Opening 斜指 · 斜指
An opening where Black’s second stone is placed one space away from the first. The 13 indirect openings are the even-numbered entries (2, 4, 6, … 26) in the 26-opening canon.
Swap2 交换2 · スワップ2
The modern RIF tournament opening rule. Player A places three stones; Player B then chooses a side, or places two more stones and hands the choice back. Swap2 neutralizes the opening-memorization advantage and balances first move.
26 Designated Openings 26种开局 · 26の珠
The canonical opening patterns codified by the Renju International Federation, each with a Japanese name (Kagetsu, Pugetsu, Shōgetsu, etc.). The first three moves must follow one of these patterns in tournament Renju.
Center (H8) 天元 · 天元
The center intersection — H8 on a 15×15 board. Always the first move and the strongest starting point, since a central stone reaches the most lines in every direction.
Star Point 星位 · 星
A marked reference point on the board. In gomoku the center star (H8) is the conventional opening move; on larger Go boards star points mark handicap and reference positions.
Rules & Variants
Standard gomoku, Renju, and free-style — and the rules that distinguish them.
Standard Rules 标准规则 · 標準ルール
The basic gomoku ruleset: 15×15 board, exactly five in a row to win, no restrictions on either player. Used in casual play and on most apps and websites.
Renju 连珠 · 連珠
The professional variant of gomoku, formalized in Japan in 1899. The name means "connected pearls." Renju forbids Black from making double-threes, double-fours, and overlines to counter Black’s first-move advantage.
Free-Style 自由式 · フリースタイル
A variant where a line of six or more counts as a win (not just exactly five). Faster and more permissive than standard gomoku; common in informal online play.
Forbidden Moves 禁手 · 禁手
In Renju, the three patterns Black cannot make: double-three, double-four, and overline. If Black plays one, Black loses. White has no restrictions — the asymmetry is the balancing mechanism.
Overline Rule 长连禁手 · 長連禁手
The Renju rule that a line of six or more is a loss for Black, not merely "not a win." This removes one of Black’s easiest winning patterns and gives White a winning mechanism Black lacks.
Exactly-Five Win 恰好五子 · 五連勝
The standard and Renju win condition: an unbroken line of exactly five stones. Six does not count (it is an overline), and four is one short. Free-style is the only common variant where six counts.
Draw 和局 · 引き分け
When the board fills up without either player making five in a row. Rare in casual play but possible, especially between defensive players on a full 15×15 board.
RIF 国际连珠联盟 · 国際連珠連盟
The Renju International Federation, founded in 1988. The governing body for competitive Renju: it maintains the ruleset, the 26-opening canon, the Swap2 protocol, and organizes the World Championship.
Intersection 交叉点 · 交点
The point where two grid lines cross. Stones are placed on intersections (as in Go), not inside the squares. A 15×15 board has 225 intersections.
General & History
The game’s names, history, and the math and AI behind it.
Gomoku 五目並べ · 五目並べ
The Japanese name for the game, meaning "five points in a row," and the most common English name. Also called Five in a Row, Gobang, Omok (오목, Korean), and Wuzi Qi (五子棋, Chinese).
Gobang 碁盤 · 碁盤
An older English name for the game, derived from "goban," the Japanese word for the board. Largely replaced by "gomoku" in modern usage but still appears in older books and some regions.
Omok 오목 (韩) · —
The Korean name, meaning "five pebbles." Gomoku is widely played in Korea, with a competitive scene that overlaps with Renju but often uses slightly different overline rules.
Wuzi Qi 五子棋 · 五子棋
The Chinese name, "five-stone chess." Gomoku has been played in China for centuries, and modern Chinese players are among the strongest in international Renju.
Kakugo 格五 · 格五
A Heian-period (794–1185) Japanese name for an early form of the game. One of the oldest recorded references to five-in-a-row play in Japan.
Piškvorky — · —
The Czech and Slovak name for the game. Gomoku has a strong historical following in Central Europe, and the region has produced world-class Renju players.
Victor Allis 维克托·阿利斯 · ビクター・アリス
The Dutch computer scientist who proved in 1993 that standard gomoku is a first-player win, using threat-space search. His proof is why competitive play uses Renju rules.
Solved Game 已解博弈 · 解明済みゲーム
A game whose optimal outcome is mathematically proven. Standard gomoku is weakly solved (Black wins with perfect play); Renju is not solved. The label matters less for human play than it sounds.
Minimax + Alpha-Beta 极大极小+剪枝 · ミニマックス+αβ
The search algorithm most gomoku AIs use to choose moves: explore the move tree to a fixed depth, assume the opponent plays best, and prune branches that cannot improve the result. The engine on this site uses it.
Black / White Stones 黑子/白子 · 黒石/白石
The two sides. Black always moves first — a significant advantage, which is why Renju restricts Black. Traditionally played with Go stones on a Go board.
Go Board 围棋盘 · 碁盤
The traditional equipment: a wooden grid of intersections shared with Go. A 15×15 grid is standard for gomoku (Go uses 19×19), but the board and stones are the same.
Trilingual Term Comparison
Gomoku has deep roots across East Asia, so most key terms have Chinese and Japanese forms. This table collects the most important ones.
| English | 中文 (Chinese) | 日本語 (Japanese) |
|---|---|---|
| Gomoku | 五目並べ | 五目並べ |
| Five in a Row | 五连 | 五連 |
| Renju | 连珠 | 連珠 |
| Open Three | 活三 | 活三 |
| Open Four | 活四 | 活四 |
| Closed Four | 冲四 | 冲四 |
| Double-Three | 双三 | 三三 |
| Double-Four | 双四 | 四四 |
| Overline | 长连 | 長連 |
| Forbidden Move | 禁手 | 禁手 |
| VCF | 连续冲四 | 連続四 |
| Center (H8) | 天元 | 天元 |