Gomoku Winning Strategy: Open Threes, Fours and Defense

Gomoku has the simplest rules of any board game, yet games are often decided within a dozen moves. The core is judging "threat levels" — when to attack, when you absolutely must block, and which shapes are winning kills. This article explains first-move logic in the plainest language possible, so you can stop placing stones on instinct.

How to Play

Black and white alternate placing stones on the board's intersections; the first to line up five in a row — horizontally, vertically, or diagonally — wins. Official tournament rules impose forbidden moves on the first player (such as double-three, double-four, and overlines), but casual games usually skip them: first to five wins. The board's center point has the widest reach in every direction and is the recognized opening key point.

Pro Tips

1. Learn the threat levels: An open three is a row of three open at both ends — one move from an open four; a four-threat is four with one gap to five but only a single completing point; an open four can complete at either end and is all but winning. Threat levels dictate how the opponent must respond — and they set your own defensive priorities.
2. Take the center in the opening: As the first player, place your first stone on the center point and your second beside it to form a diagonal or straight two, letting lines develop in multiple directions; as the second player, defend around the outer edge of the opponent's stones to avoid being pinched.
3. Make every move carry a threat: Experts create a new open two or open three with every stone, denying the opponent time to arrange freely. Before each move ask yourself: what problem does this pose for the opponent? A move with no threat is a gift of time.
4. Use fours to force tempo: A four-threat forces an immediate block — use that to "earn" a free move before your real killing blow. Play the four first, then the key stone, often completing a four-three double kill in a single stroke.
5. Always answer an open three: When the opponent forms one, either block one end or counter with your own four-threat to fight for the initiative; ignoring it hands over an open four — essentially a confession of defeat.
6. Combined kills are the real killers: Single threats can all be blocked. Double threats like the "four-three" (one move creating both a four-threat and an open three) or a pair of open threes are the winning moves. When setting up a kill, deliberately keep two lines alive and light them both with the final stone.

Common Mistakes

• Lining up without threatening: Quietly arranging two stones in a row that the opponent doesn't even bother blocking. Effective attack means "forcing a response," not "looking tidy."
• Defending only by blocking: Seeing a three and blocking the three, seeing a four and blocking the four, led around by the nose the entire game. Before blocking, look for a four-threat counter to seize the initiative — turn passive into active.
• Piling stones in one spot: Every piece crowded into one corner means single-direction lines that are easily sealed. Keep your stones spread across directions, able to support each other within two or three moves.

Advanced Strategy

Gomoku is at bottom a contest of "first-move rights": whoever first forces the opponent into a "must respond" loop owns the rhythm. The first step of training is learning to calculate — seeing your own open three, project the next three to four forced moves: I play the four, where does he block? If I make an open four, is he saved? The required-entry kill to study is VCF (Victory by Continuous Fours): forcing the opponent to respond with four-threats the whole way until five, with every step leaving no choice. Spend ten minutes a day dissecting one kill puzzle, and in a month your nose for "killing shapes" will be transformed — winning turns from accident into inevitability.

Related Guides

• Othello Advanced Strategy — the same attack-defense duel; practice initiative and choice.
• Chinese Chess Basics — the advanced version of opening and first-move theory.
• Sudoku Solving Techniques — training the calculation of step-by-step forced deduction.