Abstract: A management system for credit-operated games machines (2) has a central control device (19) which communicates with the machines (2) at their respective sites via wireless data link. GSM mobile phone technology with SMS text messaging is used. Machine operation and performance data can be uploaded from the machines (2) to the central control device (19) and data and commands can be sent to and from the central control device (19) and the machines (2). The machines (2) may be video terminals programmed with multiple games which are authenticated and enabled via the wireless data link. The machines (2) may incorporate Wireless Interface Modules (18) and the central control device (19) may be linked via the internet to the wireless net work using gateway application software (21). A machine player can obtain game-playing credit by mobile phone (22) communication with the central control device (19) which debits his account and sends credit commands to the machine (2).