Five in a Row: Play, Learn, and Understand

What Is Five in a Row?

Two players alternate placing black and white stones on the intersections of a grid. The goal is simple to state: be the first to line up exactly five stones in a row, horizontally, vertically, or diagonally. The difficulty lives in the rules that sit underneath that simple statement — board size, whether a line of six counts as a win, whether Black has restrictions on its opening moves, and how the first move is handled. Two people can sit down and disagree on all of these and still call themselves "playing Gomoku."

The browser game on this page uses an exact-five rule: a line of exactly five wins; a line of six or more does not. It is not a full implementation of the formal Renju ruleset. If you want the tournament rules, see the rules comparison before you try to carry a tactic from one variant to another.

A Short History

The earliest written records of a five-stone line game on a Go board date to the Zhou dynasty, roughly 1,000 years before the common era. It was a byproduct of Go: a smaller, faster game that could be played on the same board with fewer pieces. The game spread through East Asia alongside Go, and the modern form — a dedicated 15×15 grid, distinct from the 19×19 Go board — took shape in the early 20th century. The Renju International Federation (RIF), founded in 1972, is the body that standardizes the formal rules today, including Black's opening restrictions and the swap rule that equalizes the first-move advantage.

In 1994, Dutch computer scientist Victor Allis published a result showing that the first player wins on a standard unrestricted 15×15 board. That result is specific to a defined board and ruleset — it does not automatically apply to Renju, to smaller boards, or to the casual exact-five rule used in most apps. If someone tells you Gomoku is "solved," ask which version they mean. The scope of that result is worth reading before treating the game as decided.

How to Play This Site's Game

1. Choose a board and mode. Play against the local AI or use pass-and-play with another person. Available sizes are 9×9, 13×13, and 15×15.
2. Place one stone each turn. Black starts; stones stay on the board after they are placed.
3. Make exactly five. An unbroken line of exactly five wins. A line of six or more does not. A full board with no winner is a draw.

For a guided walkthrough of opening positions and the first ten moves, visit How to Play Gomoku.

Why the Game Has Lasted 3,000 Years

The game survives because it is easy to learn and genuinely hard to master. A new player can be competitive in ten minutes; a strong player can study openings for a decade. The rule set is small enough that two people with a pencil and a piece of paper can start a real game anywhere — no app, no board, no instructions. That portability is a large part of why Gomoku is the default board game in East Asian schools and parks.

The formal Renju rules add a layer of strategy that casual play does not touch. Black's restrictions — no overline, no double-four, most double-threes forbidden — exist because unrestricted first-player Gomoku is a known win for Black. The swap rule, in which Black places the first stone and White may swap, was designed to reduce that advantage without making the opening random. These are not arbitrary constraints; they are the product of a long tradition of trying to make the game fair while keeping it deep.

The game also has a clean cultural story. It is not a commercial product with a corporate owner; it is a shared tradition with a formal international body, a national team structure in China and Japan, and a decades-long research program on its endgame positions. That combination of folk simplicity and academic depth is what keeps it alive.

Frequently Asked Questions