Tournament Practice Mode
Practice with the official rules of the Renju International Federation (RIF) World Championship. 15×15 board with Black forbidden moves (禁手) — 三三, 四四, and 長連 — exactly as used in the international title.
The Renju International Federation (RIF) is the world governing body for competitive Renju, organizing the World Championship since 1989. Below are the core rules used in the championship's main groups, which this practice board enforces automatically.
Played on a 15×15 grid. One player uses black stones, the other white stones. Black always moves first.
The first player to form an unbroken line of five stones horizontally, vertically, or diagonally wins. White may also win with five or more (overline allowed for White). Black must form exactly five — six or more is a forbidden move.
To balance Black's first-move advantage, Black is forbidden from creating three patterns. If Black plays a forbidden move, Black loses immediately:
Black can only win by a 四三 (Four-Three) — one four and one three from the same move.
If the entire board fills up without either player forming five in a row, the game is a draw.
Note on opening rules: RIF uses advanced opening systems such as Swap2 and Taraguchi-10 to further neutralize Black's first-move advantage in tournament play. The core competitive rules above — 15×15 board and Black forbidden moves — are what this practice board enforces.
The Renju International Federation (RIF) was established in 1988 in Stockholm, Sweden, by three founding countries: Japan, Sweden, and the USSR. RIF is the world governing body for Renju and organizes the official World Championship.
The RIF World Championship has been held since 1989, making it the longest-running international Renju title. Over time, RIF split the championship into the Renju World Championship and the Gomoku World Championship to separately crown champions under each rule set.
The forbidden-move (禁手) rules are the defining feature of international Renju. Because Gomoku is a solved game where Black (first player) can force a win with perfect play, the 禁手 rules are essential for fair competition at the world level. They force Black to play more carefully and strategically, making the game balanced and interesting at the highest level.
Black has three types of forbidden moves: 三三禁手 (double three) — creating two or more live threes in one move; 四四禁手 (double four) — creating two or more fours in one move; and 長連禁手 (overline) — forming six or more consecutive stones. If Black makes any of these moves, Black loses the game.
No. White has no forbidden moves. White can win with five, six, or more consecutive stones. The restrictions apply only to Black to compensate for the first-move advantage.
No. In RIF Renju rules, Black can only win with exactly five consecutive stones. Six or more is a 長連禁手 (overline) and results in an immediate loss for Black. White, however, can win with five or more.
A 四三 (four-three) is the standard winning move for Black: a single stone that creates both a "four" (four consecutive stones with at least one open end) and a "three" (three consecutive stones with both ends open) at the same time. Since Black cannot use double-fours or double-threes, the four-three is Black's primary winning method.
RIF tournaments use advanced opening systems such as Swap2 and Taraguchi-10 to balance Black's first-move advantage. These openings let players swap colors or add extra stones before the main game begins. This practice board focuses on the core competitive rules — 15×15 board and Black forbidden moves — which apply across all RIF opening variants.