You need five stones of your colour in an unbroken straight line: across, up and down, or diagonally. The first player to make five wins at once.
Five. The first player to place a stone that completes an unbroken line of five of their own stones wins the game on the spot. The name says it: go means five and moku means pieces.
Which lines count
- Horizontal: five side by side on one row.
- Vertical: five stacked on one column.
- Diagonal: five along a slant, in either direction.
The stones must be next to each other with no gaps and no opposing stone among them. Four stones, an empty point and a fifth stone is not a win until you fill the gap, and your opponent will usually fill it first.
The line can be made of stones you placed at any time in the game. Only your colour counts, and the line may be longer than five: see whether six in a row wins. If the board fills up first, the game is a draw.
Because every line of five must be built one stone at a time, most of the game is about forcing your opponent to answer threats. The Gomoku strategy guide explains the shapes that matter.