By Yangqing

Ten Practical Gomoku Opening Decisions

This is a checklist of ten decisions that arise in casual Gomoku openings, not a ranked list of ten named positions or proven winning moves. The examples use the site's exact-five rules unless a different variant is named. Try a choice on a board, note the opponent's strongest reply, and keep the ideas that survive that test.

What "Best" Means Before the First Stone

A good opening in casual play does three jobs at once. It preserves enough empty space that your future lines can point in more than one direction. It does not hand your opponent a clean shape they can extend without complication. And it gives you something to say about move two and move three before you actually play them, so the opening is not a single move but a short plan.

The center square leaves room in every direction on an empty board, which is why it is a practical answer to "where do I start." But "start in the center" is not a plan by itself, and the rest of this article is about what to do in the five moves after it, because that is where the actual difference between players shows up.

Ten questions to ask in the opening

The three diagrams below illustrate the first questions. Coordinates use A–O and rows 1–15; move numbers describe one possible practice sequence, not an official Renju opening.

1. Take the center first

On an empty casual board, a center stone leaves extension room on both sides of four possible line orientations. That makes it an easy choice for beginners. This is a spatial observation, not proof that every engine or strong player must choose the exact center under every rule set. The interesting comparison starts with the next move and the replies it permits.

2. Answer with a close, off-center stone

If you are second and the opponent opens in the center, a nearby reply keeps both players' next decisions in the same part of the board. A diagonally adjacent square is one option to test. A distant reply may give Black time to build unopposed, but its value depends on the actual plan and board size; compare concrete continuations before calling it a mistake.

3. Compare extending a line with branching away

Once you have two stones, compare two ideas: extend their existing line, or place the next stone so it may support another line as well. Neither is automatically stronger. The useful habit is to name the empty intersections each idea needs and ask whether the opponent can occupy one first.

4. Check both ends and both diagonals

When the opponent has two stones in a row, inspect both ends and both diagonal orientations before blocking. An end near the board edge may have less room, while another end may support several future lines. No fixed “diagonal first” rule replaces checking the full position, the next player, and immediate counter-threats.

5. Avoid building your own blocked three early

A three with one end sealed by an opponent's stone has fewer immediate extensions than one with two open ends. In the fragment below, White occupies G8, so Black's H8–J8 row can grow only toward K8. That does not make the three useless; it tells Black to check whether this single direction is urgent enough or another line deserves a move.

6. Reserve one square as a future open four

An open four has two empty winning ends. If the opponent has no immediate counter-win or special rule escape, a single reply can cover only one end, so the player with the four can finish five on the next turn. Early play should preserve useful empty intersections, but an empty pair alone is not a threat. It becomes relevant only when the surrounding stones support a legal sequence.

7. Do not mistake a straight three for a finished plan

A straight three may be useful when both ends are open or when it forces a response. It is also easy to see and may be blocked before it becomes a decisive four. Check its endpoints, the opponent's next threat, and whether a move on another line would give you a second useful option. The right choice depends on the complete position, not a ban on making three in a row.

8. Use the edge only after the center is decided

An edge or corner stone has less room on one side of several lines, so a beginner may find it harder to build flexible threats there. That does not make every edge move a mistake. If a move at the edge blocks a win or completes a legal five, its immediate purpose matters more than a general center preference. Check the current position before applying opening advice.

9. Second-move replies define the opening more than the first move does

In casual play, a central first move is a practical default, but it does not settle the opening. On move two the players first diverge, and their replies matter more than an untested claim that one first move is uniquely best. Two players can both open sensibly and still end up in completely different games by move three, and that is where one opening has started to feel cramped and the other still has room. If you only remember one sentence from this list, let it be that the opening is really the first three moves, not the first one.

10. Match the opening to the board size you agreed on

A 9×9 game and a 15×15 game can call for different opening tempos. The center remains a useful empty-board default, but nearby edge constraints arrive sooner on 9×9. On 15×15 there is more room to change direction. If you copy an opening idea across sizes, test whether the required extension points still exist after the opponent's reply.

Choosing Your Opening Before the Game Starts

You do not need to memorize a long list of named positions. You need a short, repeatable decision that takes five seconds before the first move, and a short one again before move two:

1. If the board is empty, consider the center and name the rule set you are using.
2. If you are second and the center is taken, compare a diagonal reply with at least one other nearby reply. Which leaves useful lines for both players?
3. On move three, compare extending an existing line with building another. For each candidate, write down the opponent's most useful fourth move.
4. Before calling either candidate a threat, check whether the opponent can answer all of its winning points or win first on another line.

What Makes These Work, Without the Jargon

Everything above is a version of one idea: keep the number of open directions high, and keep at least one structure the opponent cannot fully block. The ten items are not ten separate tricks. They are ten different places the same idea shows up, from the very first center stone to the decision to leave one edge square empty. Once you see them as one idea, you stop needing the list. The list is for the early stage of learning, when the habit of checking both of your own open directions and one of the opponent's is not automatic yet.

If you want the pattern names used above put next to their formal definitions, the Gomoku glossary covers open three, open four, double three, and VCF with examples, so the casual language in this article and the formal vocabulary used in the strategy guides line up.

Frequently Asked Questions

Reviewed 2026-10-13. For the formal Renju opening procedure and its named patterns, see the Renju opening guide. For the pattern vocabulary used throughout, see the glossary.