Drop your discs into the grid and get four in a row — across, down or diagonally — before your opponent does. Play the computer on three levels, or pass the phone back and forth.
Tap any column. Your disc falls to the lowest free space.
Line up four of your colour across, down or diagonally to win.
Watch your opponent's three in a row and cut the line off.
The centre column sits in more winning lines than any other.
Easy makes mistakes. Hard looks eight moves ahead and rarely does.
Pass and play on one phone — no computer opponent involved.