Gomoku is a game of five in a row. Two players place stones on the crossings of a large grid, and the first to make an unbroken line of five wins. The rules take half a minute to learn, but the threats that build up can be quite clever.

How to play

The board has 15 lines each way, and the stones go on the crossings of those lines, not inside the squares. Dark plays first. At the start of a game you choose whether to play dark or light.

On a computer: click a crossing to place your stone.
On a phone or tablet: tap a crossing to mark it, and tap the same crossing again, or press Place, to put your stone there. The two taps are there so a fat fingertip does not put a stone in the wrong spot.

You take turns with the computer. A line can run across, up and down, or on a slant. Five or more of the same color in a row wins. If the board fills up with no winner, the game is a draw.

The levels

Easy: the computer stops any four you build, and otherwise plays close to the stones already down. Undo is on.
Medium: it likes to build lines of its own and to block yours. Undo is on.
Hard: it looks several moves ahead. There is no undo.
Expert: it hunts for forced wins, where a chain of threats leaves you no way out, and it checks that your tricks are not coming. It thinks for about 300 milliseconds a move. There is no undo.

Today's game

There is a Medium game each day, the same for every player. If you leave it half done, the game is saved on this device so you can finish it later that day.

Tips

Play near the middle at the start. A stone in the center has room to grow in every direction, and a stone near the edge has not.
Know the words three and four. A line of four with an open end must be blocked at once, or the next stone wins.
An open three is a row of three with free space at both ends. If you leave one, the opponent can turn it into an open four, which cannot be stopped. Block it early.
Aim for a double threat. A move that makes a four and an open three at the same time gives the opponent no way to answer both.
When you play dark, use the first move. Dark has a clear advantage in this game, so playing light on Medium or Hard is a good challenge.
Do not only attack. Before every move, look at the board from the other side and ask what the computer would play there.
Keep your stones linked. Scattered stones make threats slowly, while stones that share lines make them quickly.

A bit of history

The name comes from Japanese words meaning five stones, and the game is traditionally played with the stones and board used for Go.

Questions

Why do I need two taps on a phone? The crossings are close together. The first tap shows where your stone will go, and the second confirms it.

Does a line of six win? Yes. Five or more in a row counts.

Can I choose light? Yes, when you start a new game. Dark moves first, so light goes second.

Is Undo available? On Easy and Medium, yes. Hard and Expert do not allow it.

Gomoku