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Gomoku Rules: Five in a Row, Free Rule, No 3-3 and Renju Explained
Gomoku is one of the simplest board games to learn: two players take turns placing stones, and the first to line up five wins. The details, though, change from place to place. Some rule sets let anything go, some bar the double three, and renju puts limits on Black only. This guide was written by the JWorld team while building the rules into Hanpan, our free gomoku and janggi game, and every mark in the diagrams was checked against the game's own forbidden-move code.
Play gomoku freeThe basics
- The board has 15×15 lines and stones go on the intersections. Hanpan names columns A to O from the left and rows 1 to 15 from the bottom; the center point is H8.
- Black moves first, then the players alternate one stone at a time. Stones never move or get captured.
- Five stones of one color in an unbroken line, horizontally, vertically or diagonally, wins. If the board fills up with no winner, it is a draw.
Threes and fours
Everything else in gomoku is about threats. A four is a line that becomes five with one more stone; the opponent must block it at once. An open four can become five at either end, so it cannot be stopped. A three is a line that becomes an open four with one more stone, either solid (●●● with space on both sides) or split (●●_●). A three that is blocked on one side, by an enemy stone or the edge, is not a three, because it can no longer grow into an open four.
Making two threats with one stone is how most games are won: the opponent can block only one. A four-three (a four plus a three) is legal in every rule set and is the classic winning shape. The double three and the double four are where the rule sets disagree.
Three rule sets
| Free rule | No 3-3 (Hanpan default) | Renju | |
|---|---|---|---|
| Double three (3-3) | allowed | forbidden for both colors | forbidden for Black |
| Double four (4-4) | allowed | allowed | forbidden for Black |
| Six or more (overline) | wins | may be played, does not win | Black: forbidden; White: wins |
| First move | anywhere | anywhere | Black on the center (H8) |
Free rule: five or more wins for both players and nothing is forbidden. It is the easiest to learn, but Black has a big edge; on a 15×15 board a winning strategy for Black has been proven.
No 3-3: the rule most commonly played in Korea and Hanpan's default. Neither color may make a double three, double fours are fine, and only exactly five wins. Some apps bar Black alone, so check before you play elsewhere.
Renju: the international rule set. Black may not make a double three, a double four or an overline, while White has no limits and wins with six too. See Renju forbidden moves for the details.
Five beats everything
Under both the no 3-3 rule and renju, a stone that makes exactly five wins even if it also forms a double three or a double four. The forbidden-move check only applies to moves that do not win on the spot.
How Hanpan shows it
- Pick the rule in the settings: Free, No 3-3 (default) or Renju (without the opening rules).
- Forbidden points for the player to move are marked with a red ✕ and cannot be tapped. Turning the marks off in the settings hides the ✕ but keeps the block.
- The ten gomoku opponents on the AI ladder play under the rule you choose. Each daily puzzle shows its rule; all of them are verified under no 3-3.
Korean readers: 오목 33 금지 규칙, 렌주룰 금수.
Play gomoku nowMore rules guides
한국어 안내: 장기 두는 법 · 장기 상차림 · 오목 33 금지 규칙 · 렌주룰 금수
Written and drawn by the Js at JWorld. Rule details vary between clubs and apps; this guide follows the rules used in Hanpan. Boards are drawn in code, with no generative-AI images.