Four in a row wins. Drop wisely.
Players take turns dropping a disc into one of the seven columns. The disc falls to the lowest free space.
The first to line up four of their discs in a row, horizontally, vertically or diagonally, wins. If the board fills up first, it's a draw.
Keyboard: ← → pick a column, Enter or ↓ drops, 1–7 drop straight into a column.