Gomoku vs Connect Four: Key Differences Explained

If you've played Connect Four and are curious about Gomoku — or vice versa — you might assume they're basically the same game with a different board. In fact, they share only a surface-level similarity: you're trying to build a line of your pieces before your opponent does. Under the surface, the mechanics, strategy, and competitive depth are quite different.

Quick Overview

Feature	Gomoku	Connect Four
Goal	5 in a row	4 in a row
Board size	15×15 (or 19×19)	7×6 (vertical)
Piece placement	Any empty intersection	Drop into columns; gravity applies
Total positions	Astronomically large	4.5 trillion possible positions
Solved by computer?	Partially (with specific rules)	Yes — first player can always force a win
Average game length	30–60 moves	21–41 moves
Competitive scene	Active — world championships, Renju variant	Limited
Origins	Japan/China, ~1,000+ years old	Milton Bradley, 1974

Rules: How Each Game Is Played

Gomoku rules

In Gomoku, two players alternate placing stones — Black and White — on any empty intersection of a 15×15 grid. The first player to get exactly five consecutive stones in a row (horizontally, vertically, or diagonally) wins. In standard freestyle Gomoku, six or more in a row (an "overline") does not count as a win.

In the tournament variant Renju, Black is further restricted from making certain double-three or double-four formations that would be immediately winning — this balances Black's first-move advantage.

Connect Four rules

In Connect Four, players alternate dropping colored discs into one of seven vertical columns. Discs fall to the lowest available row in the chosen column due to gravity. The first player to connect four discs in a row — horizontally, vertically, or diagonally — wins. If the board fills completely without a winner, the game is a draw.

Board Size and Layout

The board size difference is dramatic. Gomoku is played on a 15×15 grid (225 intersections), while Connect Four is played on a 7×6 grid (42 cells). That's more than five times as many positions. This alone creates a fundamentally different feel: Gomoku games sprawl across the board in complex, branching patterns, while Connect Four games are tightly contained and resolved in a relatively small space.

The larger board in Gomoku means that both players have far more options on every turn, making the game exponentially harder to analyze exhaustively.

Gravity: The Biggest Mechanical Difference

The defining mechanical difference between the two games is gravity. In Connect Four, you cannot choose which row to place your disc — it always falls to the bottom-most available row in the column you select. This fundamentally limits your options and creates a completely different set of tactical patterns.

In Gomoku, you can place your stone on any empty intersection. This freedom is both a blessing and a challenge: you have far more options per turn, which increases strategic depth but also makes it much harder to evaluate positions without experience.

Strategy Depth Compared

Connect Four strategy

Despite its small board, Connect Four has genuine strategy. Expert play involves:

• Column management: Controlling which rows are accessible at any given point is crucial — sometimes you intentionally avoid filling a column so you can use it later.
• Odd/even analysis: Whether a critical cell is in an odd or even row determines which player gets access to it first — this is a core concept in expert Connect Four.
• Zugzwang: Creating positions where any move your opponent makes hands you a win — common in high-level Connect Four endgames.

However, because the board is small and the game has been completely solved, there is a finite "correct" game from any position. With optimal play, the first player always wins on a standard 7×6 board.

Gomoku strategy

Gomoku has a far larger strategic space. Key concepts include:

• Threat sequences: Building open threes → open fours → five in a row through a sequence of forcing moves
• Forks (double threats): Creating two simultaneous threats so your opponent can only block one
• VCF (Victory by Continuous Fours): An advanced forced-win sequence where every move is an open-four threat
• Opening theory: Like chess, serious Gomoku players study established opening lines and their best responses

Gomoku has not been fully solved for the standard 15×15 board. While it is known that Black (first player) has a theoretical winning advantage in freestyle Gomoku, the game tree is too large to exhaustively analyze, which means human skill still determines the outcome in practice.

Is Connect Four Solved? What About Gomoku?

Connect Four is fully solved. In 1988, James Dow Allen and Victor Allis independently proved that the first player can always force a win with perfect play on a standard 7×6 board. A perfect computer player will never lose Connect Four. This means that at the highest level, the game's outcome is predetermined — the question is only whether the second player makes a mistake.

Gomoku is partially solved. In freestyle Gomoku (no restrictions on where Black can play), it has been proven that Black has a first-move advantage and can force a win — but the specific winning strategy requires sequences that are impractical for human players to memorize. In practice, both players are effectively playing in an unsolved game. This is why Gomoku at high levels remains genuinely competitive and unpredictable.

In the Renju variant (with restrictions on Black's moves), the game is considered balanced and is played competitively at the world championship level.

Which Is Harder to Master?

Gomoku has a significantly higher skill ceiling. Connect Four can be approached with full memorization — a player who has studied the solved game tree can play near-perfectly. Gomoku, by contrast, has a strategic depth comparable to Go or Chess: there is always more to learn, new patterns to study, and new opponents to face who surprise you.

That said, Connect Four is harder to play well as a beginner in a specific sense — the gravity mechanic and odd/even analysis require non-obvious thinking that isn't immediately intuitive. Gomoku's rules are more transparent and its patterns more visually obvious to new players.

Who Each Game Is Best For

Final Verdict

Gomoku and Connect Four both scratch a similar itch — the satisfaction of building a line of pieces — but they deliver very different experiences. Connect Four is more accessible and faster-paced, making it ideal for family game nights and casual play. Gomoku is deeper and more strategically rich, with a skill ceiling high enough to sustain competitive play at the world championship level.

If you've been playing Connect Four and want a game that grows with you as a strategic thinker, Gomoku is the natural next step. The core instincts transfer — reading lines, spotting threats, creating double attacks — but the larger board and freedom of placement open up a much wider world of strategy.