How to play Connect Four

Connect Four takes about thirty seconds to explain and rather longer to play well. This page covers the rules properly, including the two or three details that casual players get wrong, and then points you at the strategy once you know what the pieces do.

The board and the pieces

The standard board is a vertical grid, seven columns wide and six rows deep, which gives forty-two slots in total. It stands upright, so the columns are open at the top and closed at the bottom.

Two players share the board, one taking the red discs and one the yellow. Each player has twenty-one discs, which is exactly half the board: if a game runs its full course, every slot gets filled and neither player has anything left over.

The rules

• Decide who goes first. Moving first is a genuine advantage, so the usual courtesy is to alternate who starts across a series of games.
• Players take turns. On your turn you drop exactly one disc of your colour into any column that is not already full.
• You choose the column, never the row. Gravity does the rest, and the disc comes to rest in the lowest free slot of that column, on top of whatever is already there.
• A full column is simply out of play. If all six slots are taken, you must drop somewhere else.
• You win the moment four of your own discs sit in an unbroken line of four. The line can run horizontally, vertically, or diagonally in either direction.
• Discs are never moved or removed once played, and you can never skip a turn.
• If all forty-two slots fill with no line of four anywhere on the board, the game is a draw.

The bit people get wrong

Two misunderstandings come up again and again.

The first is diagonals. A line of four running diagonally counts exactly the same as one running along a row, and it counts in both directions — up to the right and up to the left. Diagonal wins are easy to miss precisely because players scan rows and columns and forget to look across them.

The second is the shape of a legal move. You are not placing a disc on a square of your choosing, you are choosing a column and accepting whichever row you are given. That single constraint is what makes Connect Four a real game rather than a race, because it means you are constantly building the platform your opponent will stand on. Drop a disc directly beneath a slot that completes their line and you have handed them the game.

Longer than four? Shorter?

Four is the target, but nothing stops a line being longer. Five of your discs in a row contains a winning four inside it, so it is a win — the game simply ends at the moment the fourth one lands.

Three in a row, meanwhile, is worth naming because it is the engine of the whole game. Three of your discs with an open slot at either end is a threat, and a move that creates two threats at once cannot be defended. That is the single most useful idea in Connect Four, and it has its own article.

Variants worth knowing

Once the basic game feels comfortable, the published variations change it more than you would expect. Pop Out lets players remove one of their own discs from the bottom of a column instead of dropping a new one, so the board can shrink as well as grow. Pop 10 takes that further, with players collecting the discs they pop and needing ten of them to win. Five-in-a-Row does what the name says, on a wider board. Power Up hands out discs with special abilities.

All of them are recognisable as the same game, and all of them break the careful counting that decides ordinary Connect Four.

Now play a few

The board on the front page plays by exactly the rules above. Two players can share one device, or you can take on the Easy bot while the rules bed in and the Hard bot once they have. When you start losing games you feel you should have won, the strategy page explains why the centre column matters so much and how the odd and even rows quietly decide tight endings.

Connect Four questions, answered