To further enhance interest in a game by a display device provided separately from a reel.

First determination for determining a game prize symbol combination that can be established from among a plurality of game prize symbol combinations, a first symbol is variably displayed by a reel, and the first symbol relating to the determined game prize symbol combination can be stopped. Also, second determination is performed to determine a winning mode that can be established from among a plurality of winning modes including a winning mode correlated with the game prize symbol combination, and a second symbol relating to the determined winning mode can be displayed on a display device. Then, a normal mode for performing only the first determination and a chance mode for performing the first determination and the second determination are provided. While a result of the first determination is displayed on the display device in the normal mode, a result of the second determination is displayed on the display device in the chance mode. Thus, since amusement using a second display means changes depending on the game mode, interest in a game can be enhanced.