Gomoku Board Size: 13×13 vs 15×15 vs 19×19
Gomoku is usually played on 15×15, but 13×13 and 19×19 boards change the game more than most players expect. Here is how each size plays, and which one to choose for your first hundred games.
What size is a gomoku board?
The standard competitive board is 15 × 15: fifteen lines each way, which makes 225 intersections. That is the size used in renju championships, on most gomoku sites, and on the board here. But it is not the only size — 13×13 boards are common in casual and mobile games, 19×19 boards reuse the go board, and small 9×9 boards are used to teach children.
The sizes compared
| Board | Points | Typical use | How it plays |
|---|---|---|---|
| 9×9 | 81 | Teaching, quick games | Very fast; a single open three is often decisive |
| 13×13 | 169 | Casual and mobile games | Shorter games, threats arrive sooner, less room to rebuild after a mistake |
| 15×15 | 225 | Standard, competition, renju | The classic balance: enough space to develop, short enough for a ten-minute game |
| 19×19 | 361 | Variety, go players, long games | More space and longer games; opening mistakes are easier to recover from, threats take longer to mature |
Why 15×15 became the standard
Fifteen by fifteen is the size the modern competitive game grew up on, and it hits a sweet spot. A 9×9 board is over almost as soon as it begins; a 19×19 board can run long enough that casual players lose patience. At 15×15 a game typically lasts between ten and forty moves — long enough for real strategy, short enough to play a rematch.
It is also the size the theory is written for: renju's rules and its 26 named openings assume a 15×15 board, and the 1993 proof that the first player wins under free-style play is a 15×15 result.
How board size changes strategy
On smaller boards, tempo is everything. With fewer intersections, an open three becomes a four much sooner, and there is less room to switch flanks. If you lose the first fight on a 13×13 board, you rarely get a second one.
On larger boards, patience pays. A 19×19 board gives you space to build two or three separate threats before committing, and the player who overextends first is usually the one who loses. Openings matter a little less, because there is time to recover.
Which size should you play?
Start on 15×15 unless you have a reason not to. It is the standard, it is what most guides (including this site's strategy tips) assume, and it is the size you will meet in competition. If you want quick practice games, 13×13 is a good second board. Play 19×19 when you want a slower, more sprawling game — or when you are already comfortable on the standard board.
Our free gomoku board is 15×15, the standard size. If you beat the computer on Medium, try the same opening on a bigger board to feel the difference for yourself.
Last updated: November 2026