Gomoku

🕹️ How to play

1. Start a 2 player game: There is no start button and no room code - the 15x15 board is already set up. The status bar above it says whose turn it is and the whole bar changes colour with the side to move, so two people sitting opposite each other can read it at a glance. On a touchscreen the first tap drops a translucent stone with its coordinate; hold and drag to nudge it onto the right intersection, then tap the same point again or press Place to commit. With a mouse a single click plays the stone.
2. Win a round: Get five of your stones in an unbroken line - horizontal, vertical or either diagonal. This page uses free-style rules: neither colour has forbidden moves, double threes and double fours are legal, and six or more in a row wins just the same. The winning run lights up, a line sweeps through it, and the result card rises with the score.
3. Fix a mis-tap: Three layers, none of them behind an ad. A stone is only pending until you confirm it, and that confirmation is on by default on touchscreens; you can hold and drag the pending stone onto the intersection you actually meant; and Take back is always there, unlimited, rewinding one move against another person or your move plus the computer's reply against the machine. Even after a result, the card offers Take it back and play on, which unwinds the point it just recorded before it lifts the stone.
4. Play the computer: Switch the top control to vs computer and the level row opens in place. Rookie builds its own line and rarely blocks yours; Steady answers open threes and fours but slips roughly one time in four; Sharp looks two moves ahead and hunts for points that open two lines at once. None of the three ever ignores a four, so beating Sharp means building two threats it can only answer one of. A 9x9 quick board in settings brings a round down to under three minutes.

📖 Rules & variants

Board and stones: 15x15 intersections by default (225 points), switchable to a 9x9 quick board in settings. Stones go on the intersections, not inside the squares. Black opens, then the two sides alternate; stones never move and nothing is ever captured. Coordinates follow the international notation - columns A to O, rows numbered 1 to 15 from the bottom - so the centre point is H8. Tapping an occupied intersection does nothing at all: no flash, no message, no move counted. In a round shared between two people that happens a dozen times, and an error chime would just become noise.

Free-style rules, no forbidden moves: five or more of one colour in an unbroken horizontal, vertical or diagonal line wins. Both colours may play double threes, double fours and overlines, and six or seven in a row wins exactly like five. Sites disagree wildly on this point, so it is stated three times here - beside the board, in this section, and in the FAQ - because losing to a rule nobody showed you is the worst way to learn a game. If all 225 intersections fill with no line, the round is drawn, which almost never happens in practice. There is no clock and no timeout loss.

Going first, and the score: opening really is an advantage in five in a row, and the answer here is rotation. Seat one opens rounds 1, 3 and 5; seat two opens rounds 2, 4 and 6; and the Play again button spells out who takes black next. The scoreboard carries the score, the number of drawn rounds, the round number and the move count. A round is recorded at exactly one moment - the stone that decides it - so reloading the page or taking a move back never counts it twice. New match in settings resets the score; Restart round throws away the position without consuming a round number.

Threat notes and review: whenever either side makes an open three, a four, an open four or a double threat, a line appears under the status bar naming the shape and the exact coordinates involved, then folds into a small badge until the next stone. It is symmetric - flagging only one player would be cheating in a shared round - and it only ever describes stones already on the board; it never suggests where to play. The result card adds one sentence explaining which move, at which coordinate, created the shape that decided the round, and a Review button steps through the whole game move by move with the board read-only.

Vocabulary and four habits: an open three is a three that becomes an open four with one more stone (including the split shape with a gap in the middle); a four with one completion point forces an answer; an open four has two completion points; a double threat is one stone opening two lines at once. From that: play near the centre early, because more lines run through it; aim for the intersection where two of your lines cross rather than extending one line at a time; when the other side makes an open three, either take one of its two ends or make a four of your own to seize the initiative back; and remember an open four has two completing points while a stone only covers one, so deal with a three before it becomes one.

❓ FAQ