In 1993 gomoku was solved: with perfect play on a 15×15 board under free-style rules, Black wins. That result shaped every competitive variant since.
Free-style gomoku
The simple version, and what this board plays. Five or more in a row wins, both players may make any shape, and there are no restrictions. It is the easiest to learn and the least balanced.
In casual play the imbalance matters less than it sounds, because neither player is playing perfectly. Black has a real but modest practical edge — roughly the equivalent of a small head start.
Renju
The Japanese competitive form. It keeps five in a row as the win condition but forbids Black from making certain shapes, because those shapes are what make the first-player win possible.
- Double three — Black may not make two open threes with one stone.
- Double four — Black may not make two fours with one stone.
- Overline — six or more in a row does not win for Black; it is a forbidden move.
White has no restrictions at all and may use every one of those shapes. If Black plays a forbidden move, Black loses immediately. The result is a game that is very close to balanced, at the cost of rules that take some getting used to.
Swap and Swap2
A different approach: instead of restricting shapes, restrict who chooses colours. In Swap2, one player places three stones — two black, one white — and the opponent then chooses to take either colour, or to add two more stones and hand the choice back.
This is elegant because it balances the game without changing any rule of play. The player setting up the position has to make it genuinely equal, since they do not know which side they will get. Most modern international tournaments use it.
Board size variants
Some versions use 19×19, borrowing a go board. The larger board slightly favours the attacker because there is more room for combinations, so it does not solve the balance problem — but it does make the game longer and more positional.
| Variant | Board | Balance | Complexity of rules |
|---|---|---|---|
| Free-style gomoku | 15×15 | Black favoured | Minimal |
| Renju | 15×15 | Close to even | Moderate |
| Swap2 gomoku | 15×15 | Close to even | Low, but needs a protocol |
| Gomoku on 19×19 | 19×19 | Black favoured | Minimal |
Which should you play?
For learning, free-style. The threat patterns, combinations and defensive ideas are identical across all variants, and free-style lets you concentrate on them without also tracking which of your shapes are illegal.
If you want a balanced game here, choose White. That single change removes the first-move advantage in the most direct way possible and makes every difficulty level harder.
What transfers
Everything tactical. Open threes, fours, four-three combinations, crossing points and blocking choice all work identically under every rule set. The only thing that changes is which shapes Black is allowed to use, and that is a constraint on one player rather than a different game.