How to play Gomoku

Gomoku is a game of five in a row. Two players take turns placing stones on the points of a grid, and the first to line up five of their own stones in a straight line, across, down or diagonally, wins. Think of it as a much bigger, much sharper version of tic-tac-toe: the board is too large to fill by accident, so every game is decided by attack and defence.

The rules can be explained in one sentence, but strong play takes real skill. A good player builds several threats at once, so that blocking one lets the other through, while keeping an eye on every line the opponent is building. There is no luck involved; the board shows everything.

How to play on skill.games

In the settings popup choose a difficulty (Easy, Normal, Hard or Crazy) and press PLAY. The board has 13 x 13 points. You play the white stones and you always place first; the computer plays the dark stones.

• Placing a stone: tap an empty point. If the points feel small, press anywhere on the board instead: a ghost stone appears on the nearest free point and follows your finger as you slide, and lifting your finger places the stone where the ghost is.
• Taken points cannot be played; a tap there is simply refused.
• The latest stone is marked with a small dot, so you can always see where the computer just played.
• Score line: the top of the screen shows how many stones each side has placed and whose turn it is.

The menu button in the top-left corner pauses the game and lets you resume, start a new game or switch the sound on or off. The position is saved at every turn, so an unfinished game can be continued next time with CONTINUE.

When someone completes a line, it lights up across the stones, then the results screen appears with the outcome, the stones each side placed and the length of the winning line, plus your statistics for that difficulty: wins, losses, win rate, current streak and best streak (draws are counted too once one happens).

Rules

• The board starts empty. You place first, then you and the computer take turns.
• On your turn you place one stone of your colour on any empty point. Stones are never moved or removed.
• Five or more in a row wins. The line can be horizontal, vertical or diagonal. This version is free-style Gomoku: a line of six or more stones also wins, and there are no forbidden moves for either side.
• A five completed with the very last stone on the board still wins.
• If every point is filled and nobody has five in a row, the game is a draw.

Strategy tips

• Learn the key shapes. An open four is four in a row with both ends empty: your opponent can block only one end, so it wins next move. An open three has both ends free and threatens to become an open four, so it must be answered at once.
• Block threes early. When the computer makes an open three, block one end immediately. Waiting until it becomes four is usually too late.
• Make two threats with one stone. The winning idea in Gomoku is the double threat: a single stone that creates two open threes, or a four and an open three, at the same time. The opponent can block only one.
• Attack while you defend. The best blocking stone also extends one of your own lines. A purely defensive move hands the initiative back.
• Keep your stones close together. Stones that are one or two points apart can join several lines at once. Scattered stones rarely build anything.
• Use the first move. You always start, which is an advantage in Gomoku. Play near the centre, where lines can run in every direction.
• Look at all four directions. Before every move, scan the computer's stones horizontally, vertically and on both diagonals. Lost games usually come from a diagonal nobody noticed.

Difficulty levels

• Easy: judges only its next move, pays less attention to blocking you and often picks a weaker move on purpose. Red rings warn you of any point where the computer could complete five with its next stone.
• Normal: judges only its next move, but defends almost as carefully as it attacks and makes occasional mistakes.
• Hard: looks a couple of moves ahead, considering your best replies, and makes no deliberate mistakes.
• Crazy: looks several moves ahead and considers more candidate moves each turn. The strongest level, and hard to beat.