An operation input interface includes multiple selection buttons for a player to play a prize money game, and an information output interface includes multiple selection items comprising hidden contents and positions associated with the selection buttons. The hidden contents of the selection items include multiple rewards and at least one ending option. After the prize game starts, the selection items and the selection buttons are respectively provided at the information output interface and the operation input interface to allow the player to select the selection buttons to further display the hidden contents. When any of the at least one ending option is displayed by the information output interface, the prize money game ends immediately. Thus, the player is allowed to play the prize money game intuitively, and provides the player with the pleasure of ending the prize money game unexpectedly by ending the prize money game randomly.