Standard opening positions relative to the center star point
What Is an Opening Formation?
In competitive Gomoku, the first three moves define the entire character of the game. Black places the first stone at center, White responds, and Black places the third stone. Each unique combination of these first three stones is called an "opening formation." There are exactly 26 recognized openings in standard Renju rules, of which 15 are considered classic and commonly played.
Learning openings is the fastest way to improve your win rate. Memorizing just a handful of formations gives you a roadmap for the first 10–15 moves, allowing you to avoid common mistakes and seize early initiative.
Direct Openings (Shidashi)
Direct openings occur when White places the second stone directly adjacent to Black's first stone — either horizontally or vertically. These positions tend to produce sharp, tactical games with early confrontation.
1. Cold Star (Kansei)
One of the most defensive openings. White plays directly above center, creating a tight vertical pair. Favored by patient players who prefer positional battles over early tactics.
2. Mountain Moon (Sangetsu)
Black's third stone forms an L-shape. A balanced opening with both attacking and defensive possibilities. Popular at intermediate levels for its flexibility.
3. Flower Moon (Kagetsu)
One of the strongest attacking openings for Black. Creates immediate threat potential in two directions. Considered an aggressive choice that demands precise defense from White.
4. Black Star (Kokusei)
A straightforward, direct formation. Black extends horizontally while White blocks vertically. Leads to open, fighting-style games with clear lines of battle.
5. Silver Moon (Gingetsu)
A subtle positional opening. Black places the third stone one step back, creating a flexible structure that can transition into multiple midgame patterns.
Diagonal Openings (Shachiku)
Diagonal openings happen when White places the second stone diagonally adjacent to Black's center stone. These openings generally lead to more strategic, positional games with slower development.
6. River Moon (Suigetsu)
The most famous diagonal opening. Black forms a diagonal two-stone line with White positioned at a 45-degree angle. A deep opening with hundreds of known variations.
7. Rain Star (Uisei)
A sharp diagonal opening with strong attacking potential. Black creates a scattered formation that threatens multiple lines simultaneously. Requires accurate defensive calculation.
8. Earth Star (Chisei)
A solid, reliable opening. Black builds a compact diamond shape that is hard to attack. Often chosen by players who want to avoid complex theory and reach a balanced midgame.
9. Wind Moon (Fūgetsu)
A dynamic opening with asymmetrical development. Black stretches in one direction while White controls the opposite diagonal. Leads to complex, double-edged positions.
10. Cloud Moon (Ungetsu)
A deep positional opening. Both players build slowly, focusing on structure rather than immediate threats. Rewards long-term strategic planning over tactical sharpness.
5 More Essential Formations
Beyond the ten core direct and diagonal openings, these five formations appear frequently in tournament play and are worth adding to your repertoire.
11. Swallow's Wing (Ensei)
A wide, expansive opening. Black places the third stone farther from center, controlling more territory but leaving gaps to exploit.
12. Double Moon (Sōgetsu)
Features two separate two-stone groups. Creates multiple independent threats that White must defend simultaneously.
13. Snake Head (Dato)
An irregular, tricky opening designed to catch opponents off-guard. Breaks standard patterns and forces White onto unfamiliar ground.
14. Golden Rooster (Kinkeishi)
A classic attacking formation with strong diagonal potential. Known for its beautiful follow-up patterns and forcing sequences.
15. Turtle Shell (Kikō)
The most defensive of all standard openings. Black builds a thick, protective structure and waits for White to overextend before counterattacking.
Beginner Recommendation
If you are new to openings, start with just two: Flower Moon as Black (simple, aggressive, and effective) and Cold Star as White (solid, easy to defend, and hard to go wrong with). Master these two thoroughly before expanding your repertoire. Quality beats quantity when it comes to opening knowledge.