A method of playing a gambling game-device on a standard, conventional personal computer utilizing at least one floppy disk or smart card that is purchased from a licensed vendor or provider. When the disk or smart card is purchased, a predetermined, gambling credit-balance is credited to the "credit balance" field of the "wage-related control information" section of the disk or card. From that credit-balance, the purchaser may bet any desired amount, up to the maximum credited, during the playing of the gambling game. Before the start of play of the game, the player is asked the amount of his wager, whereupon, that amount is deducted from the "credit-balance" field and debited to the "debit-field". After having played the gambling game, the winnings, if any, are then credited to the "credit-field", or the losses, if any, are debit to the "debit-field" of the disk or card. After the player has used up all of the credit-balance, or if the credit-balance has reached a predetermined maximum, by means of one or more winnings, then the disk or card having the "wage-related control information" section is returned to the vendor or provider, for either the purchase of a new "credit-balance", or for the collection of the monies won. In a variation, a dedicated, portable computer unit is provided for use with a smart-card reader incorporating the gambling game software therein.