Patent ID: 7452277

Claim:
A network game system, comprising: a center server; and a game machine, communicatively connected to the center server and operable to execute a game program, wherein: the center server comprises a first transmitter, which transmits, to the game machine, first data indicating a settled play amount out of a played amount which is represented by either an accumulated number or time period that the game program has been executed; and the game machine comprises: a first storage, operable to store the first data; a second storage, operable to store second data indicating the played amount; a first receiver, which receives the first data transmitted by the first transmitter; an updater, which updates the first data stored in the first storage with the first data received by the first receiver; a third storage, operable to store third data indicating an allowable unsettled play amount which represents either an allowable number or time period of which the game program is executed without settlement; a comparator, which obtains an unsettled play amount as a difference between the first data and the second data, and compares the unsettled amount with the third data; and a controller, which allows execution of the game program when the unsettled play amount is no greater than a predetermined amount, and inhibits execution of the game program when the unsettled amount is greater than the predetermined amount.