To provide a Pachinko game system for easily finding a fraudulent action to prevent the subtraction of the balance of a prepaid recording medium by forcibly changing the signal level of a ball dispensing completion signal to be transmitted from a Pachinko game machine to a prepaid recording medium reader.

When the put-out of dispensed balls is completed, the put-out control board 60 of the Pachinko game machine 1 transmits, to the prepaid recording medium reader 100, a ball dispensing completion signal EXS for performing changes multiple times between a high level and a low level in the one cycle of the signal. The CPU 121 of the prepaid recording medium reader 100 analyzes the received ball dispensing completion signal EXS (S9), and when the signal is not the normal ball dispensing completion signal EXS (S10: No), performs an error notification (S12).