Highly entertaining games are provided. When a trigger condition is established in a normal game, the following processes are executed: a process of shifting to a bonus game in which a re-trigger condition which is less stringent than the trigger condition may be established; a process of executing a free game at least once in the bonus game; and a process of increasing the number of times of execution of the free game in the bonus game, when the re-trigger condition is established in the bonus game.