Gomoku: Align Five Stones in a Row

Gomoku: Five Stones in a Row is a tactical board game intended for two players. It is traditionally played on a 19x19 square grid, though the modern sports variant uses a 15x15 grid. Players alternate in placing stones of two different colors on the board. The goal is to be the first to form an unbroken line of five stones of the same color, whether vertically, horizontally, or diagonally. The game includes several rule variations with minor differences. It is thought to have started in China more than two thousand years ago and has become popular worldwide, with international competitive tournaments.