Gomoku on a 15×15 board: get five stones in a row. Play the computer at three levels or a friend on one device; online games are in the lobby.
What is Gomoku?
Gomoku is a two-player strategy game in which players take turns placing stones on the points of a grid, and the first to make an unbroken line of five, horizontally, vertically or diagonally, wins. It is also called five in a row, and in Vietnam it is known as caro. Stones are never moved or captured once placed, so every move stays on the board for the rest of the game.
The rules take seconds to learn. The depth comes from threats: a strong player creates two threats with one move, and the opponent can only block one.
How to play Gomoku
Our Gomoku is played on a 15x15 board, the traditional size. Black moves first, then White, one stone per turn on any empty point.
The first player to get five stones in a row in any of the four directions wins. In our version a line of six or more also wins, and it does not matter whether the ends of the line are blocked by enemy stones. If all 225 points fill up without a line of five, the game is a draw.
Against the computer you pick Easy, Medium or Hard and decide who moves first, you or the computer. You can also play two players on one device, taking turns. The page also has an online lobby where you can play against other people.
Gomoku strategy: threats and how to win
Know the shapes. A four is four stones in a line with one empty point that would complete five; it must be answered at once. An open four has both ends free, like a row of four with empty points on each side; it cannot be stopped, because blocking one end leaves the other. An open three is three stones that can become an open four in one move, either solid with free ends or split with one gap, like two stones, a gap and a third stone. An open three must be blocked, or it becomes an open four.
Win with double threats. The usual winning move creates two threats at once. The four-three is the most common: one stone makes a four and an open three together. Your opponent has to block the four, and the three then becomes an open four. A double open three (three-three) and a double four (four-four) win the same way. In our freestyle rules all three are allowed for both players.
Chain your fours. A sequence of fours, each forcing a block, can lead your stones into position for a double threat. Players call this victory by continuous fours. Before you start such a chain, check that none of the forced blocks gives your opponent a four of their own, which would let them take over the attack.
Keep the initiative. Whoever is making threats decides where the game goes. When your opponent has no threat to answer, use your move to build shapes that work in several directions at once. Diagonal lines are the ones opponents miss most often.
Defend early and in the right spot. Block open threes as soon as they appear. For a split three, blocking the gap is usually the strongest answer, because it breaks the shape in the middle. When you block, prefer the point that also extends one of your own lines.
Play near the centre. Lines need room on both sides. Stones near the edge have fewer ways to become five, so the centre area is where games are won. In freestyle Gomoku the first player has a clear edge; computer analysis in the 1990s showed that with perfect play the first player always wins on a 15x15 board. When you move second, start close to the first stone and focus on defence.
Gomoku variants: caro rules and Renju
Our game uses freestyle rules: five or more in a row wins, with no restrictions for either side.
Other variants exist. Standard Gomoku counts only exactly five, so a line of six does not win. Renju gives Black, the first player, restrictions on double threes, double fours and lines longer than five, plus special opening rules, to balance the first-move advantage. In Vietnam many people play caro with the blocked-ends rule, where a five that is blocked by opposing stones at both ends does not count. Tournaments also use opening swap rules so the first player cannot simply play a known winning start.
Where Gomoku comes from
Gomoku comes from Japan, where it was played with go stones on a go board; the name refers to placing five stones in a line. The same game spread under other names and with other equipment. In Vietnam it is called caro and is often played by students on squared notebook paper with X and O, on a grid as large as the page. Renju developed in Japan as the formal, rule-balanced version for competitive play.
Playing Gomoku on Hevagames
Gomoku on Hevagames runs in the browser on phones and computers, with no download. The board fits a phone screen without zooming. On a touch screen, the first tap shows a preview stone and a second tap on the same point places it, so a slip of the finger does not cost you a game. With a mouse a click places the stone directly, and on a keyboard the arrow keys move and Enter or Space places.
The last move is marked, the winning line is highlighted, and the board frame takes the colour of the side to move. Undo takes back your last move and the computer's reply, even after a lost game, so you can replay the critical moment. Your unfinished game is saved, and your win streak against the computer and your best streak are kept on your device.
How to play
- 1Choose vs Computer (Easy, Medium or Hard, and who moves first) or 2 Players. Black moves first.
- 2On a phone, tap a point to preview your stone, then tap the same point again to place it. A mouse click places it at once.
- 3Five or more stones in an unbroken line across, down or diagonally wins. A full board is a draw.
Controls
Tips
- An open four (four in a row with both ends free) cannot be blocked.
- Block your rival's open threes before building your own line.
- The small dot marks the last stone played.
