To obtain a variety of performance contents without increasing the kinds of image performances, and also to output the performance to be easily understood by even a beginner.

The mode of a performance image is selected from a normal mode and an interpretation mode (a beginner mode) when a game is not being played. When the normal mode is selected, the performance image and a first reel image are displayed and also the first reel image is displayed by rotation and stop with the rotation and stop of the reel. On the contrary, when the interpretation mode is selected, the reel image is not displayed or the less number of symbols is displayed compared with the first reel image, and also a second reel image is displayed, where the display area of the reel image is reduced. Besides, the performance image is displayed, and characters for expressing which content of the performance image at present or in the future makes a symbol combination winning expectation degree higher are displayed in an area including at least a part of the display area of the first reel image in the normal mode.