The cards are printed with representative battleships, aircraft carriers, cruisers, and destroyers of World War II. In the game, the first player to attack organizes an invasion fleet from a hand of five cards, while the second player organizes a defense fleet from a hand of seven cards. The first player to attack wins the game when he or she withstands the attack of the defending fleet and succeeds in a direct attack. Otherwise, the player with more victory points gained by sinking the opponent's battle ships wins the game. Cards are discarded when used for attack, so it is important to organize the invasion fleet efficiently.