A reference strength (P) is set at a game device (10) as a received signal strength enabling stable communication in a range in which radio waves reach from a wireless relay device (20) (radio wave coverage range), and permits a game play at a portable terminal (30), for which the received signal strength reaches the set reference strength (P). Thus, it is possible to permit players in an area satisfying store manager's wishes to perform remote play under a stable communication environment, without being influenced by a decrease in an effective communication speed.