Gomoku Glossary: Complete Dictionary of Five in a Row Terms

Refers to intersections that are directly next to each other on the board — horizontally, vertically, or diagonally. Two stones are adjacent when they occupy neighboring intersections with no empty points between them. Adjacency is the fundamental building block of all formations in Gomoku; you need five adjacent stones in a straight line to win.

Example: "Place your stone adjacent to your existing three to create an open four."

A stone or group of stones that still has the potential to contribute to a winning five-in-a-row formation. An alive group has at least one open end or path that is not completely blocked by the opponent. The opposite of alive is dead. In Gomoku, keeping your groups alive while making your opponent's groups dead is a core strategic goal.

Example: "That three is still alive — it can extend in both directions."

The player who makes the first move in a game of Gomoku. By universal convention, Black always moves first. Because going first provides a significant strategic advantage — Gomoku on a 15×15 board has been mathematically proven to be a theoretical win for the first player under freestyle rules — many tournament rule sets impose restrictions on Black (such as forbidden moves in Renju) or use swap opening protocols to mitigate this advantage.

Example: "Black opens at tengen and immediately begins building influence over the center."

A defensive move that prevents the opponent from extending a formation into a winning line. Blocking is one of the most fundamental defensive techniques in Gomoku. A well-timed block can shut down an opponent's threat, but indiscriminate blocking without creating counter-threats of your own is a common beginner mistake. The most efficient blocks simultaneously defend against the opponent's threat while advancing your own position. See our strategy guide for more on effective blocking.

Example: "White must block Black's open three immediately or face a forced loss."

The playing surface for Gomoku, consisting of a grid of horizontal and vertical lines. The standard competitive board is 15×15 (225 intersections), though 19×19 (the standard Go board) is also commonly used for casual play. Smaller boards such as 9×9 or 13×13 exist for quick games and teaching. Stones are placed on the intersections of the lines, not inside the squares. In online platforms like Gomoku Five, the board is rendered digitally with click-to-place interaction.

Example: "The standard tournament board is 15×15 with 225 playable intersections."

A mechanic found in the Pente variant of Gomoku (and in Ninuki-Renju) in which a player can remove an opponent's pair of adjacent stones from the board by flanking them — placing stones on both ends of the pair in a straight line. Capturing five pairs (10 stones total) is an alternate win condition in Pente. Standard Gomoku and Renju do not include a capture mechanic; once placed, stones are never removed.

Example: "In Pente, White captures by placing stones at both ends of two adjacent Black stones."

An opening in which Black places the first stone on tengen, the center point of the board. This is the most common and traditional first move in Gomoku because the center provides maximum influence in all directions. In professional Renju, the first move is required to be at tengen. Also known as a direct opening. See our complete openings guide for analysis of center-based first moves.

Example: "Most high-level games begin with a center opening at H8 on a 15×15 board."

A formation of four stones in a line where only one end is open (the other end is blocked by an opponent's stone or the edge of the board). A closed four is a threat because it can become five on the next move, but it can be defended with a single blocking move. Compare with open four, which has both ends open and is generally indefensible. Also called a half-open four or straight four with one blocked end.

Example: "A closed four forces the opponent to respond, but it can always be blocked."

A variant of the connection game family played on a 19×19 board. Black places one stone first, then both players alternate placing two stones per turn. The goal is to be the first to form an unbroken line of six stones. Connect6 was invented by Professor I-Chen Wu in 2003 specifically to address the first-player advantage inherent in Gomoku. It is considered more balanced than standard Gomoku without needing forbidden-move rules. Learn more about game variants in our rules article.

Example: "Connect6 is popular in Taiwan and has its own competitive tournament scene."

A stone or group of stones that can no longer contribute to forming a five-in-a-row line because all possible extension paths are completely blocked by the opponent or by the board's edges. Dead stones waste moves and provide no strategic value. Recognizing when a group is dead — and avoiding investing further moves in it — is an important intermediate-level skill. The opposite of alive.

Example: "Don't extend that group — it's dead. Both ends are blocked."

One of the four directions in which a line of five can be formed on the Gomoku board. Diagonal lines run from one corner direction to the opposite (e.g., top-left to bottom-right, or top-right to bottom-left). Along with horizontal and vertical lines, diagonals are equally valid for forming a winning five-in-a-row. Diagonals are often harder for beginners to spot, making diagonal threats particularly effective at lower levels of play.

Example: "Watch the diagonals — beginners often miss diagonal threats."

In Renju, a direct opening refers to one of the 26 officially recognized opening patterns where the first three stones (two Black, one White) are placed within or adjacent to the center of the board. Each direct opening has a traditional Japanese name (such as Kagetsu) and has been extensively analyzed in professional play. Direct openings contrast with indirect openings, where the second Black stone is placed further from center.

Example: "The 26 direct openings in Renju are named after celestial bodies and natural phenomena."

A single move that simultaneously creates two separate fours (either open or closed). A double four is extremely powerful because the opponent can only block one of the two fours, meaning the other will complete on the next turn to form a winning five. In Renju, creating a double four is a forbidden move for Black. This is one of the most decisive tactical patterns in Gomoku. See patterns for visual examples.

Example: "Black plays a double four — White cannot block both fours, so Black wins next move."

A single move that simultaneously creates two separate open threes. Because each open three threatens to become an open four on the next turn, and the opponent cannot block both at once, a double three is typically a winning fork. Under Renju rules, creating a double three is a forbidden move for Black, which is one of the key rule differences between Renju and freestyle Gomoku.

Example: "The double three is forbidden for Black in Renju — White can exploit this restriction."

A game result in which neither player achieves five in a row. In theory, a draw occurs when all intersections on the board are filled without either player completing a line of five. In practice, draws are relatively rare on a 15×15 board in competitive play because one player usually achieves a forced win well before the board fills up. In some tournament formats, draws may be resolved by tiebreakers or declared when both players agree that no winning line is achievable.

Example: "Draws are uncommon in professional Gomoku — most games end in a decisive win."

The outer rows and columns of the board, bordering the boundary of the playing area. Edge intersections have fewer directions available for building lines, which limits their strategic versatility. Formations near the edge are easier to block because the boundary itself acts as a natural wall. In competitive Gomoku, strong players rarely play near the edge in the opening, preferring the center where stones exert influence in all four directions.

Example: "Avoid opening near the edge — the board boundary limits your attacking options."

A line of precisely five consecutive same-colored stones, with no extension to six or more. Under standard Renju rules, only an exact five counts as a win — an overline (six or more in a row) does not win for Black. In freestyle Gomoku, however, overlines typically count as wins. The distinction between "exact five" and "five or more" is an important rules difference between Renju and freestyle variants.

Example: "In Renju, Black must make exactly five — six in a row doesn't count as a win."

The winning condition in Gomoku: an unbroken, continuous line of exactly five (or, in freestyle, five or more) same-colored stones placed horizontally, vertically, or diagonally on the board. "Five in a Row" is also used as an English-language name for the game itself. It is the most widely understood name for the game among English-speaking casual players who may not know the Japanese term "Gomoku." Learn the full rules in our complete rules guide.

Example: "The first player to get five in a row wins the game."

In Renju rules, certain moves that are illegal for Black (the first player). The three types of forbidden moves are: double three (三三, creating two open threes simultaneously), double four (四四, creating two fours simultaneously), and overline (長連, forming six or more in a row). If Black plays a forbidden move, Black immediately loses the game. These restrictions exist to balance the game against Black's inherent first-move advantage. White has no forbidden moves. Learn more in our Gomoku vs Renju comparison.

Example: "Black must be careful — that move would create a double three and is forbidden in Renju."

A move that creates two or more simultaneous threats that the opponent cannot all defend against in a single move. Forks are the primary winning mechanism in Gomoku. The most common forks are double threes (creating two open threes), double fours (creating two fours), and three-four forks (creating one open three and one four simultaneously). A fork is essentially a checkmate-like situation where the game is decided. Mastering fork creation is the key to progressing from beginner to intermediate level. See our strategy guide for fork-building techniques.

Example: "Black creates a three-four fork — White can't block both threats."

A formation of four stones in a row with at least one empty intersection at one or both ends that, if filled, would complete a five in a row. An open four has both ends open and is virtually indefensible. A closed four (also called a half-open four) has one end blocked and can be stopped by blocking the single open end. Fours are the most dangerous offensive formations in the game.

Example: "Creating a four forces an immediate response from your opponent."

A two-player abstract strategy board game in which the objective is to place five of your stones in an unbroken horizontal, vertical, or diagonal row on a gridded board. The name comes from the Japanese words go (五, "five") and moku (目, "pieces" or "points"). Gomoku is one of the world's oldest and most widely played board games, with origins tracing back to ancient China over 4,000 years ago. It is known by different names across cultures — Omok in Korea, Wuziqi in China, Cờ Carô in Vietnam. Play Gomoku online for free.

Example: "Gomoku is easy to learn in minutes but takes a lifetime to master."

The full Japanese name for Gomoku, literally meaning "five pieces in a row" or "five points line-up." The shortened form "Gomoku" is more commonly used in international contexts today. Gomoku Narabe specifically refers to the traditional, unrestricted (freestyle) version of the game without the forbidden-move rules used in Renju. The game was popularized in Japan during the Meiji era and has been a beloved pastime in Japanese culture for over a century.

Example: "Gomoku Narabe is the freestyle version — no forbidden moves apply."

Describes a formation (three or four) that has only one open end. The other end is blocked by an opponent's stone or the edge of the board. A half-open three (also called a closed three or 眠三 in Chinese) is less dangerous than an open three because it can only become a four in one direction. Similarly, a half-open four is synonymous with a closed four. Half-open formations are still useful threats but are easier for the opponent to defend against.

Example: "A half-open three threatens in only one direction — it's safer to leave unblocked than an open three."

In Renju opening theory, an indirect opening is one in which the second Black stone (Black's second move, the third stone overall) is placed more than one intersection away from the first Black stone at tengen. Indirect openings tend to lead to more complex, less sharply analyzed positions compared to direct openings. They are sometimes chosen by players who prefer creative, less-studied middle-game positions over heavily-theorized lines.

Example: "Indirect openings give more room for creative play outside the main theory lines."

The point where a horizontal line and a vertical line on the Gomoku board cross. Stones are placed on intersections rather than inside the squares formed by the grid lines. A standard 15×15 board has 225 intersections. Each intersection can be in one of three states: empty, occupied by a Black stone, or occupied by a White stone. Understanding intersections is fundamental to reading coordinates (e.g., H8 = column H, row 8).

Example: "Place your stone on an empty intersection — stones go on the points where lines cross."

A term borrowed from Go, referring to established sequences of moves — typically in the opening — that are considered optimal or balanced for both players. In Gomoku and Renju, joseki represent deeply analyzed opening patterns where each move has been studied and refined over decades of professional play. Learning joseki helps players avoid early blunders and reach sound middle-game positions. In Renju, the 26 named direct openings each have their own extensive joseki. See our openings guide for key joseki sequences.

Example: "Study the joseki for the Kagetsu opening to understand the best follow-up moves."

One of the most famous and commonly played direct openings in Renju. The name means "Flower Moon" in Japanese. In the Kagetsu opening, the three initial stones form a diagonal pattern near the center. It is classified as a Black advantage opening and has been extensively analyzed for over a century. Kagetsu is one of the 26 named openings in the Renju International Federation (RIF) opening system. Explore all 26 openings in our openings guide.

Example: "Kagetsu (Flower Moon) is one of the strongest openings for Black in Renju."

A straight, unbroken sequence of stones (and/or empty intersections) running in one of the four directions: horizontal, vertical, or either diagonal. The concept of a "line" is central to Gomoku — all formations (threes, fours, fives) are defined as lines. When analyzing a position, strong players mentally scan for lines in all four directions from each stone to identify threats and opportunities.

Example: "Check all four line directions from each stone to spot threats you might miss."

A line of six or more consecutive same-colored stones. In Renju rules, an overline is a forbidden move for Black — creating six or more in a row does not win for Black and instead causes Black to lose the game. White, however, can win with an overline in Renju. In freestyle Gomoku, overlines generally count as a win for either player. The overline rule is one of the three forbidden-move restrictions in professional Renju, along with double three and double four. Also called a longline.

Example: "Black accidentally made six in a row — under Renju rules, that's an overline and Black loses!"

A Japanese title meaning "master" or "expert," historically the highest title in various classical Japanese board games including Gomoku/Renju, Go, and Shogi. In the context of Renju, the Meijin title is awarded to the winner of the Meijin-sen (名人戦), one of the oldest and most prestigious Renju tournaments in Japan. The title carries profound cultural significance in Japanese board game tradition, and was historically reserved for only one living player at a time. Today it remains one of the most respected competitive titles in Renju.

Example: "The Meijin title is the most prestigious individual honor in Japanese Renju."

A variant of Renju that adds a capture mechanic. In Ninuki-Renju, a player can remove a pair of the opponent's adjacent stones by flanking them (placing stones on both ends of the pair in a straight line). Capturing five pairs is an alternative win condition in addition to forming five in a row. Ninuki-Renju is considered a precursor to Pente and adds a dynamic element to the game not present in standard Gomoku or Renju. The name literally means "two-capture Renju."

Example: "Ninuki-Renju combines Renju's forbidden-move rules with a capture mechanic."

The Korean name for Gomoku, literally meaning "five eyes/pieces." Omok is extremely popular in South Korea and is commonly played in schools, parks, and online. The Korean version traditionally uses the standard forbidden move rules (similar to Renju) to balance the first-player advantage. Korean professional Omok players have competed at the highest international level in RIF world championships. The game holds significant cultural importance in Korean daily life.

Example: "Omok is one of the most played casual board games in South Korea."

A formation of four stones in a row with both ends open (empty intersections). An open four is essentially a guaranteed win because the opponent cannot block both ends in a single move — the player will complete the five in a row on their next turn regardless of the opponent's response. Creating an open four is the tactical goal of almost every attack in Gomoku. The only defense is to prevent open fours from ever forming. Compare with closed four.

Example: "An open four wins the game — the opponent cannot block both ends at once."

A formation of three stones in a row (or three in a line with a gap that still forms a continuous threat) with both ends open. An open three is a serious threat because it can become an open four on the next move if not blocked. However, unlike an open four, an open three can still be defended — the opponent can block one end or play in the middle to disrupt the formation. Open threes are the building blocks of winning sequences; creating two simultaneous open threes (a double three) is a fork.

Example: "An open three threatens to become an open four — your opponent must respond."

The first phase of a Gomoku game, typically encompassing the first 3–5 moves. In professional Renju, 26 standard direct openings are recognized, each named with a Japanese term (e.g., Kagetsu, Kansei, Sosei). Opening theory is one of the most deeply studied aspects of competitive Gomoku. Tournament rule sets like Swap2 and Soosõrv structure the opening phase to ensure fairness. Our openings guide covers all 26 openings in detail.

Example: "Strong opening play sets the foundation for a winning middle game."

A recognizable arrangement of stones on the board that has specific tactical significance. Common patterns include open threes, open fours, closed fours, forks, and various defensive shapes. Pattern recognition is the most important skill in Gomoku — experienced players instantly identify patterns and know how to respond to each one. Our patterns guide provides visual diagrams of all essential patterns.

Example: "Pattern recognition improves with practice — play more games and study common shapes."

An American-invented variant of Gomoku created by Gary Gabrel in 1977, typically played on a 19×19 board. Pente adds a capture mechanic to the standard five-in-a-row objective: players can remove pairs of opponent stones by flanking them (custodial capture). A player wins by either forming five in a row or capturing five pairs of opponent stones (10 stones total). Pente enjoyed significant popularity in the United States during the 1980s, with dedicated tournaments, clubs, and a commercially sold board game. See our rules article for a comparison of variants.

Example: "Pente adds captures to Gomoku — you can win by capturing five pairs of stones."

The professional, competition-grade variant of Gomoku. The name means "connected pearls" in Japanese. Renju adds forbidden move rules for Black (the first player) to balance the inherent first-move advantage: Black cannot create double threes, double fours, or overlines. White has no such restrictions. Renju is governed internationally by the RIF (Renju International Federation), which organizes world championships and maintains official rankings. Renju is the most strategically deep and competitively rigorous form of five-in-a-row. Learn about the differences in our Gomoku vs Renju article.

Example: "Renju is to Gomoku what tournament chess is to casual chess — the serious competitive version."

The international governing body for competitive Renju, founded in 1988 in Stockholm, Sweden. RIF organizes the World Renju Championship, maintains official world rankings, standardizes rules and opening protocols, and oversees national federation memberships. Member countries include Japan, China, Russia, Estonia, Sweden, South Korea, and many others. RIF has been instrumental in standardizing tournament rules such as Swap2 and Soosõrv opening protocols.

Example: "The RIF World Championship is the most prestigious title in competitive Renju."

A sophisticated tournament opening rule used in professional Renju and Gomoku, named after the Estonian word for "random" or "arbitrary." In the Soosõrv opening protocol, the first player places three stones (two Black, one White) on the board, then the second player chooses to play as Black or White (or may place additional stones before choosing, depending on the variant). Soosõrv is designed to ensure that neither player can gain an unfair advantage from pre-memorized opening theory alone. Variants of this rule are used in the RIF World Championship.

Example: "The Soosõrv opening protocol forces players to adapt rather than rely purely on memorized openings."

The playing piece used in Gomoku. Each player has a set of stones in one color — traditionally Black and White. Stones are placed one per turn on empty intersections of the board. In standard Gomoku and Renju, once a stone is placed, it cannot be moved or removed for the rest of the game (except in variants with capture rules like Pente). Physical Gomoku stones are typically made of glass, ceramic, plastic, or shell, similar to Go stones.

Example: "Each player places one stone per turn on any empty intersection."

Four stones arranged in a continuous, unbroken line with no gaps between them. A straight four with both ends open is the standard open four — the most powerful formation in Gomoku. The term "straight four" distinguishes this arrangement from a "broken four" (four stones with a gap, e.g., ●●_●● or ●●●_●), which can also function as a four if filling the gap would create five in a row. Both straight and broken fours are counted when determining double fours.

Example: "A straight four with both ends open is an immediate game-winning formation."

A family of opening rules designed to balance the first-player advantage in Gomoku. In the simplest swap rule, after the first player places a stone, the second player may choose to swap colors (taking control of the placed stone). This discourages the first player from opening with an overly aggressive or advantageous move. The most widely used tournament swap protocol is Swap2. Swap rules effectively transform Gomoku from a solved first-player-wins game into a balanced, fair competition.

Example: "Swap rules ensure the opening position is fair — no one wants to place stones that are too good."

The most popular tournament opening protocol for standard (freestyle) Gomoku. In Swap2, the first player places three stones on the board (two Black, one White), then the second player chooses one of three options: (a) play as Black, (b) play as White, or (c) place two additional stones (one Black, one White) and let the first player choose their color. Swap2 encourages the first player to create a balanced position — if the position is too favorable for Black, the opponent will simply choose Black. This protocol is endorsed by the RIF and used in most major international tournaments. See our rules guide for full details.

Example: "Under Swap2 rules, placing three dominant stones just lets your opponent take the winning side."

The center point of the board — intersection H8 on a standard 15×15 board. The name comes from the Japanese term meaning "origin of heaven." Tengen is the most strategically important intersection on the board because it provides maximum reach in all four directions and allows the first player to exert influence over the entire board. In Renju rules, Black's first stone must be placed at tengen. In freestyle Gomoku, playing first at tengen is customary rather than mandatory.

Example: "Black traditionally opens at tengen — the center of the board at H8."

Any move or formation that, if left unanswered, will allow the player to win on a subsequent turn. A four is an immediate threat (one move from winning). An open three is a secondary threat (it threatens to become an open four). In competitive Gomoku, the game is often decided by who can create threats faster — forcing the opponent into a purely defensive posture while building toward a fork. The concepts of VCF and VCT revolve around maintaining a continuous series of threats.

Example: "Every move should either create a threat or respond to one — passive play loses."

A formation of three stones in a line. An open three (活三) has both ends open and threatens to become an open four; it is a significant attacking formation. A closed three (眠三, also called a half-open three) has one end blocked and is less threatening. Threes are the workhorse formations of Gomoku strategy — players build threes, link them together, and create forks from them. In Renju, creating two open threes simultaneously (a double three) is forbidden for Black.

Example: "Building connected threes gives you more forking opportunities in the middle game."

An organized competitive event in which multiple players compete in a series of Gomoku or Renju games under standardized rules, typically with clocks and arbiters. Major international tournaments include the RIF World Renju Championship, the Gomoku World Championship, and various national championships. Tournaments use specific opening protocols (such as Swap2 or Soosõrv) and time controls. The Renju International Federation maintains a rating system similar to chess Elo ratings for ranked players.

Example: "The RIF World Championship is held every two years and attracts top players from over 20 countries."

A forced winning sequence achieved by playing a series of consecutive fours — each four forces the opponent to block, but each blocking response allows the attacker to create a new four in a different direction, culminating in an unblockable five in a row. VCF is the simplest and most common type of forced win in Gomoku. Recognizing VCF opportunities is an essential skill for intermediate and advanced players. VCF sequences are typically shorter and easier to calculate than VCT sequences. See our strategy guide for VCF examples.

Example: "Black has a VCF — a sequence of continuous fours that the opponent can't escape."

A more advanced forced winning sequence that uses a combination of fours and open threes (threats) to force a win. Unlike VCF, which uses only fours, VCT sequences include moves that create urgent open threes which the opponent must block, after which the attacker continues the threat sequence. VCT is harder to calculate than VCF because open threes can sometimes be blocked in multiple ways, creating a branching decision tree. Mastering VCT calculation is what separates advanced players from experts.

Example: "The VCT is deep — Black mixes fours and open threes to force a win in 15 moves."

The player who moves second in a game of Gomoku. White plays after Black on every turn. Because going second is a disadvantage in Gomoku (the game is a proven first-player win under freestyle rules), White benefits from special balancing mechanisms in competitive play: in Renju, Black is restricted by forbidden moves while White is not; in Swap2 tournaments, White gets to choose colors after seeing the initial position. Despite the theoretical disadvantage, skilled White players can exploit Black's forbidden-move restrictions in Renju to achieve wins.

Example: "In Renju, White has no forbidden moves — this offsets Black's first-move advantage."

The result achieved by a player who successfully places five in a row on the board (or, in Pente, who captures five pairs of opponent stones). In Renju, a player also wins if the opponent plays a forbidden move. Additionally, a player can win by timeout if the opponent exceeds their allotted time in a timed game. On Gomoku Five, wins are tracked in your player profile and contribute to your rating. Gomoku was mathematically proven to be a first-player win on a 15×15 board under freestyle rules by Victor Allis in 1994.

Example: "The first player to achieve five in a row wins — simple rules, deep strategy."

The Chinese name for Gomoku, literally meaning "five-piece chess" (五 = five, 子 = pieces, 棋 = chess/board game). Wuziqi is immensely popular in China and has a long history dating back over a thousand years. China has produced many world-class competitive players and has a thriving professional Wuziqi scene. The Chinese Wuziqi Association organizes national championships and sends teams to RIF world competitions. In recent decades, China has dominated international Renju and Gomoku tournaments, producing multiple world champions.

Example: "Wuziqi is one of the most popular board games in China, played by millions."