To enhance game properties by reconstructing lottery knowledge in a game situation wherein a prize has not been won for a long while from the turning-on of power.

The lottery knowledge 33 is copied into a random-access memory (RAM) 32 from a read-only memory (ROM) 31 with the activation of a controller 22 at the turning-on of the power; the controller 22 monitors the game situation in terms of a difference between the numbers of game balls, an investment 45 in game, the number of starting prizewinning times, or the like; a player operates a launching operating mechanism 5; the ball, which is shot into a game area, enters a starting prizewinning component 14; a starting prize-ball detector 17 outputs a starting prizewinning signal to the controller 22; the controller 22 operates the lottery for determining whether or not the prize is won, by using the lottery knowledge 34 which is copied into the RAM 32 from the the ROM 31; as a result of the lottery, when the prize is not won in the lottery, the controller 22 determines whether or not the game situation up to that time is the situation wherein the prize has not been won for a long while from the turning-on of the power; and as a result of determination, when the prize has not been won for a long while in the game situation, the control device 22 reconstructs the lottery knowledge 34 of the RAM 32, and rewrites the lottery knowledge 34 thereof into the reconstructed lottery knowledge 49.