Gomoku vs Connect Four: What's the Difference?

If you've played Connect Four and heard about gomoku (or "five in a row"), you might assume they're basically the same game with a different board. They're not. The core mechanic — form a line of pieces to win — is shared, but everything else about how the two games play is fundamentally different. One difference in particular changes everything.

The Short Version

In Connect Four, you drop pieces into a vertical 7-column rack; gravity pulls them down, and you need 4 in a row. In gomoku, you place stones on any empty intersection of a flat 15×15 grid; you need 5 in a row. Connect Four is a fun casual game. Gomoku has professional tournaments, codified opening theory, and an international federation. The gravity mechanic is what separates them — and it's a bigger deal than it sounds.

Side-by-Side

Gravity Changes Everything

This is the single biggest difference between the two games, and it shapes everything else about how they play.

In Connect Four, gravity does most of the work for you. You pick a column, and the piece drops to the lowest open slot. Your "choice" each turn is really just picking from 7 columns (sometimes fewer as the board fills). This is why Connect Four feels manageable — you're never staring at 200 options and trying to figure out which one matters. The constraint is comforting.

In gomoku, there's no gravity. You place a stone on any empty intersection. On your first move, you have 225 choices. After a few stones are on the board, you typically have 30–50 plausible moves to consider. The board is flat — pieces don't stack, they sit where you put them. This freedom is what makes gomoku strategically deep: you can build lines in any direction from any position, not just from the bottom up.

Gravity also limits planning in Connect Four. You can't place a piece in the middle of the board without filling everything below it first. You can't set up a threat in row 3 unless the columns below it are already occupied. This means your options are largely determined by the current state of the board — you're reacting to what's there. In gomoku, you can place a stone anywhere to create a future threat, even if the connecting stones aren't there yet. You're creating the board state rather than just responding to it.

Why 5-in-a-Row Is Harder Than 4-in-a-Row

It sounds obvious that making 5 in a row is harder than making 4. But the difference is bigger than you'd think, because of how it changes the defense.

In Connect Four, if your opponent has 3 in a row with an open end, you have to block — or they win next turn with 4. That's straightforward. One threat, one response. In gomoku, the threat chain is longer and more complex: your opponent can build an open-three (3 stones with both ends empty), which becomes an open-four on the next move, and an open-four is unblockable (the opponent has open ends on both sides of the 4 — they can only cover one). So you have to start blocking earlier — at the open-three stage — and by then, a skilled player may have already set up a second threat at the same time.

This is the double-threat concept that's central to gomoku strategy and barely exists in Connect Four. Connect Four's 4-in-a-row goal means threats mature quickly — there's not enough time to build two threats simultaneously. Gomoku's 5-in-a-row goal gives each threat more "runway," which creates space for the kind of multi-threat play that defines intermediate and advanced strategy.

Opening Theory: A Week vs. A Lifetime

Connect Four has 7 possible first moves (one per column), though by symmetry, column 4 (the center column) is provably the strongest — it's the optimal first move with perfect play. After that, the tree branches, but the limited column count keeps things manageable. A competent player can learn strong Connect Four play over a few weeks of study.

Gomoku has 26 designated opening patterns codified by the Renju International Federation (RIF). Each opening has a Japanese name (like "Kansei" or "Shoei") and specifies the first 3 moves. Professional players spend years studying which openings favor Black's attack and which give White better defensive chances. The opening phase alone in gomoku — the first 3 stones — is more complex than an entire game of Connect Four.

The difference isn't just breadth. It's depth. In Connect Four, once you know the center column is best, the second and third moves follow relatively logically from what your opponent plays. In gomoku, the first three moves set up the strategic character of the rest of the game — whether it'll be a tactical slugfest near the center or a wide positional battle across the board. Getting the opening right matters.

Both Are Solved — So What?

Connect Four was strongly solved in 1988 by James D. Allen and independently by Victor Allis. Gomoku was weakly solved by Allis in 1993 — Black can force a win with perfect play. So theoretically, both games are "broken" in the same way. But here's the practical difference:

In Connect Four, the solution is simple enough that a decent programmer can implement the perfect strategy in a few hundred lines of code. A motivated human can learn to play nearly perfectly with moderate practice. At the highest level, Connect Four is a draw between two perfect players — and a human can get close enough to perfect that it feels that way.

In gomoku, Allis's proof involves a strategy tree so large that no human can execute it. Even computers need significant search depth to play at the solved-game level. Two strong human players still have genuinely competitive games — the "solution" doesn't make the game trivial the way it does for Connect Four. Read the full explanation of what "solved" means →

Physical Equipment

Connect Four comes in a plastic rack that costs $10–15. The pieces drop in with a satisfying clunk. It's self-contained, portable, and instantly recognizable — leave it on a coffee table and someone will start playing within 10 minutes. This is a genuine advantage.

Gomoku is traditionally played on a Go board with Go stones (the intersection-based grid of a Go board is the same as a gomoku board). A decent board-and-stones set costs $20–50. But — and this is important — you can also play gomoku with a pencil on graph paper, or with coins on a hand-drawn grid, or on your phone. The game doesn't require a special rack the way Connect Four does. Print a free gomoku board from this site and play with anything you have lying around.

Which Should You Play?

Play Connect Four if you want a quick, tactile game to play with kids or at a party. The gravity mechanic is intuitive and fun, games are fast, and the physical rack is satisfying. It's the right call for casual social settings.

Play gomoku if you want a game where studying strategy actually pays off — where learning about open-threes, double threats, and opening patterns makes a real difference in your results. Gomoku rewards the time you put into it in a way that Connect Four can't, because Connect Four's smaller board and solved status limit how deep your study can go. Try playing gomoku here →

Play both. They scratch different itches. Connect Four is the better social game; gomoku is the better strategy game. There's room for both on your shelf (or in your browser).

The Skill Transfer Question

A common question: "If I'm good at Connect Four, will I be good at gomoku?" The answer is: a little, but not much. The pattern-recognition skills transfer — you'll spot threats faster than a complete beginner. But the strategic thinking is different enough that your Connect Four instincts will sometimes lead you astray. In Connect Four, the correct move is often defensive (block the column your opponent needs). In gomoku, the correct move is often offensive (create your own double threat rather than just blocking). Defensive instincts from Connect Four can make you too passive in gomoku, and passive play gets crushed.

The reverse transfer is stronger: if you're good at gomoku, you'll pick up Connect Four quickly. The threat-reading skills from gomoku make Connect Four's simpler threats obvious, and the positional instincts carry over. A strong gomoku player would be competitive at Connect Four within a few games. A strong Connect Four player would need weeks to become competitive at gomoku.

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