You play on a board consisting of seven columns and six lines. Each player has 21 discs of the same colour. When a player drops a disc into a column, it edges the undermost blank space. The one who manages first to create a vertical, horizontal or diagonal line of four of his own discs is the winner of the game.
In this conversion you can only play against the computer who does not memorize your playing. As a consequence every player has the same chances to win except for the general advantage of the one who starts. While playing, the game shows which player is currently in the best position to win the game.