How to Play Connect 4
Connect 4 is a two-player strategy game played on a 6-row, 7-column vertical grid. Players take turns dropping colored discs (Red and Yellow) into any column. Discs fall to the lowest available row in that column.
- 1. Click or tap a column to drop your disc into it.
- 2. Your disc will fall to the lowest empty cell in that column.
- 3. The first player to connect four discs in a straight line wins.
- 4. Lines can be horizontal, vertical, or diagonal.
- 5. If the board fills up without a winner, the game is a draw.
Winning Strategies
Control the Center
Placing discs in the center column (column 4) gives you the most connection opportunities — horizontally, vertically, and diagonally.
Build Threats
Create multiple simultaneous threats so your opponent cannot block all of them at once. A fork (two winning threats) is nearly unbeatable.
Block Diagonals
Diagonal wins are the hardest to spot. Always watch for diagonal sequences forming on both directions before making your move.
Don't Give Free Wins
Avoid filling a column if it would let your opponent complete a four-in-a-row directly above your disc.
About the AI
The Easy AI plays mostly random moves with occasional smart plays — great for beginners learning the game.
The Hard AI uses the Minimax algorithm with alpha-beta pruning at depth 5, evaluating millions of future positions to find the best move. It will consistently challenge experienced players.
History of Connect 4
Connect Four was first sold under the name "Captain's Mistress" and was later commercially published by Milton Bradley in February 1974. The game was solved by James Dow Allen in 1988: the first player can always win with perfect play by starting in the center column.
Despite being mathematically solved, the game remains extraordinarily popular because human players rarely play perfectly — leaving plenty of room for exciting, unpredictable gameplay.
FAQ
Are my scores saved?
Yes! Win counts for Red and Yellow are automatically saved to your browser's local storage and persist between sessions.
Can I play on mobile?
Absolutely. The game is fully touch-optimized. Tap any column to drop a disc.
How hard is the Hard AI?
Very challenging. It uses Minimax with alpha-beta pruning at depth 5, which means it looks several moves ahead and plays near-optimally.
What happens when the board is full?
If all 42 cells are filled and no player has connected four, the game ends as a draw.