Object of Sub Attack is to either sink enemy ships or get them safely to port depending on which side you are on. The Fleet Commander spins a spinner to possibly move one of his three ships (blue pawns). The Sub Commander draws one card per turn hoping to get a card showing the letter and color where a ship is located. If this happens, the ship is sunk. Once the Fleet Commander's last ship makes it to port, players switch sides to see how many ships the new Fleet Commander can get back to port. The player who gets the most ships back to port wins.