Gomoku Opening Strategies: How to Start Strong

A Gomoku opening is not a memorised sequence. It is the first five or six stones, in which both players decide where the fight will happen and who will be attacking when it starts. Good openings come from a handful of principles about geometry and tempo, and this guide explains them move by move.

All diagrams use X for the first player (Black in traditional Gomoku) and O for the second player. Numbers show the order of moves.

Why opening moves matter

In the opening nobody has a threat yet, so every stone is an investment. A well-placed early stone will still be part of several useful lines twenty moves later. A badly placed one either sits on lines your opponent has already blocked, or gives them a free point to build on.

The first player also starts with an extra stone. Used well, that becomes the initiative: the first player threatens and the second player answers. The opening is where the first player tries to turn the extra stone into an attack, and where the second player tries to neutralise it.

The first move

The first stone almost always goes in the centre. A central point belongs to 20 possible lines of five — more than any point near an edge — so it keeps every direction open. On a 15×15 board the centre is H8; on 5Row's 19×15 board it is J8.

There is no rule that you must start there, and on a large board a stone a point or two from the centre is just as flexible. What matters is not being so close to an edge that half your future lines are cut off before the game starts.

Centre vs edge

Edges are walls. A line pressed against an edge can only grow in one direction. Under some rule sets the edge even counts as a blocking stone; on 5Row it does not, but the lost space is enough. Early stones near an edge are weak for the player who places them and useful to the opponent, who can attack in the open space in the middle.

The practical rule: in the opening, play where there is open space in at least three directions around the stone. The Gomoku board size guide shows how quickly the number of possible lines drops as you approach an edge.

The second move: direct and indirect replies

The second player usually places the first stone right next to the opening stone. There are two families of reply, a classification borrowed from Renju opening theory:

Both are sound. A direct reply blocks one of the first stone's straight lines; an indirect reply blocks a diagonal. Either way, the second stone takes away a few of the first stone's lines immediately and stays close enough to defend.

Playing the second stone far away is the common beginner choice — and it hands the first player a free move to make a pair.

Flexible structures

The third stone is where the first player starts building. The question is how to place it so that the two X stones work together. There are three basic relationships:

• Adjacent pair — the stones touch. Strongest in the short term, because one more stone makes three. Also the most obvious, so the opponent can plan a block.
• One-point jump — the stones are on the same line with one empty point between them (X · X). Slightly slower, but the gap is a flexible point: filling it later makes three, and it can also serve another line.
• Knight's-move or two-point spacing — the stones do not share a line yet, but they share several nearby points that lie on lines through both. These shapes look loose but they create many future crossing points.

Flexible shapes are ones where the stones share more than one potential line, so a single block cannot cut them apart.

Example opening patterns

These examples show the ideas, not forced lines. There is no single correct move in any of them.

Pattern 1: a diagonal pair after a direct reply

O's stone 2 blocks X's column, so X builds on a line it does not touch. The diagonal pair is open at both ends, and stone 3 also starts new lines below and to the right, away from O.

Pattern 2: the block that builds

O had two ways to block the diagonal. The upper end is better for O because it connects with stone 2: the block is also a pair. Now X has to think about O's row as well as its own plans. This is the second player's core opening skill: every defensive stone should also stand next to your other stones.

Pattern 3: the one-point jump

Instead of a touching pair, X leaves a gap. If O blocks at a, the X stones are split; if O blocks above or below, X can fill a later to make a three — and point a is also next to O's stone 2, so it is a point both players care about. Jumps like this are harder to read than pairs, which is often their purpose.

Connecting stones and future threats

The aim of the opening is to reach the middle game with more possible lines than your opponent, and with your lines crossing each other. Two habits help:

1. Every new stone should touch or nearly touch your existing stones — within one or two points. Isolated stones take too long to become useful.
2. Every new stone should add a new direction. If your third and fifth stones both extend the same row, your opponent needs only one block. If they extend a row and a diagonal that cross, your opponent has to block twice.

The empty points where your lines cross are your future double threats. The Gomoku tactics guide shows what happens when one of them is finally filled.

Reading your opponent's opening

When your opponent plays, ask three questions:

• Which of their stones now share a line? Each pair is a potential three.
• Which empty points lie on two of their lines? Those are where their threats will come from.
• Which of my stones does their move neutralise? A good opening move often blocks you while building for them.

If you find an empty point that lies on two of their lines and one of yours, that is usually your move.

Common opening mistakes

• Starting near the edge. It throws away lines before the game begins.
• Answering from far away. The second player who does not stay close lets the first player build freely.
• Blocking too early. Blocking a lone pair before it matters spends a move that could have built your own shape. Block pairs only when the block also builds.
• Building one line only. A straight line of three in the opening is easy to stop and tells your opponent exactly where to look.
• Copying shapes without checking the position. A pattern that works with O's stones in one place can fail with them one point away.

Beginner opening principles

1. First stone in or near the centre.
2. As the second player, reply next to the first stone, directly or diagonally.
3. Make stones work in pairs, and in more than one direction.
4. Block with stones that also connect to your own.
5. Leave room around your stones; avoid the edges.
6. Before each move, find the empty points your opponent's stones share.

The Gomoku strategy guide explains the reasoning behind each of these in more depth. To make them habits, play the same opening several times in a row against the computer opponent and watch where it breaks down.

Variation-specific considerations

Competitive Gomoku and Renju do not let the first player simply choose the opening. Gomoku tournaments commonly use swap2: one player places the first three stones, and the other either picks a colour or adds two more stones and hands the choice back. Because the opener may end up with either colour, they have every reason to propose a balanced position. Renju uses formal opening rules and restricts Black's moves throughout the game; the Gomoku vs Renju comparison explains both.

On 5Row there is no opening rule: X simply moves first. Three things are worth knowing:

• The board is 19 columns by 15 rows, so there is more room left and right of the centre (J8) than above and below it.
• With the two-end rule on (the default), a five boxed in at both ends — including by the edge — does not win. Openings that keep lines in the open middle are worth even more.
• In ranked matches, sides are random, so you need openings for both X and O.

The Gomoku rules page has the full details, and how to play Gomoku shows an opening turning into a win in a complete beginner game.

FAQ

Is there a best first move in Gomoku?

The centre is the standard choice, because it keeps the most lines open. Moves one point away from the centre are also fine. Moves near the edge give away some of the first-move advantage.

As the second player, should I copy the first player's moves?

No. A mirrored move usually lands on the other side of the board, far from the threat it should be answering. Respond to what their stones are doing, not to where they are.

Do I need to memorise openings?

Not to play well casually. Learn the principles first. Memorised openings mainly matter in competitive play with fixed opening rules.

What if my opponent starts on the edge?

Play near the centre. An edge start is a gift of space: build your own shape in the open area and let them come to you.