How to play Connect 4
Connect 4 is a classic vertical strategy game: two players drop discs into a standing grid and race to line up four. Easy to learn, and deep enough to have been mathematically solved.
The goal: drop discs into a 7-column, 6-row grid and be first to connect four of them in a row — horizontally, vertically, or diagonally.
Rules
- The board stands upright: 7 columns, 6 rows
- Red moves first, then players alternate
- Choose a column; the disc falls to the lowest free cell in it
- You cannot place a disc in mid-air or remove one once dropped
- Win: four of your discs in an unbroken line in any direction
The shapes that win
Four across
A horizontal line of four — the most common win.
Four up
A vertical stack. Easy to miss because discs pile upward, not sideways.
Four diagonal
A stair-step line — the hardest shape for a beginner to see coming.
Double threat
Two different columns would both complete four. Your opponent can only block one.
Strategy
1. Fight for the centre column
The middle column belongs to more winning lines than any other. Controlling it early multiplies your threats.
2. Build two ways to win
Set up so that two different drops would complete a four. One block is never enough against a genuine double threat.
3. Check vertical threats every turn
Because discs stack, vertical danger hides in plain sight. Scan each column for an opponent sitting one disc from four.
4. Never hand them the square above
Dropping below a winning cell gives the opponent a free win. Before every move, check what they could do immediately after it.
Pro tip: always ask what the board looks like after your disc lands. A move that sets up your own four but fills their winning cell loses the game.
Playing here
Modes on BoardDuel: vs AI — play a live engine at three difficulty levels; Pass & play — two players, one screen; Friend room — share a six-character code and play remotely.
Frequently asked
Do diagonal lines count?
Yes. Horizontal, vertical and diagonal all count — all three directions are winning lines.
What if the board fills with no winner?
The game is a draw. It is uncommon in well-played games, since most end long before all 42 cells fill.
Is Connect 4 solved?
Yes — with perfect play the first player has a forced win. Finding that line over the board is hard enough that casual games stay competitive.