A method of a shared jackpot system of a gambling apparatus unit is provided, where the gambling apparatus unit comprises a plurality of coin-operated gambling machines. The gambling machines are linked to each other and jointly fill a jackpot. A predetermined part of the gambling bet of each gambling machine is employed to fill the jackpot. The filling level of the jackpot is displayed on each gambling machine and with a large display. A communication board is coordinated to each gambling apparatus in addition to a control unit. Upon actuation of the gambling machines, it is automatically determined which one of the gambling machines assumes the control in the form of a master. The master gambling machine monitors whether a jackpot trigger value is present. In case a jackpot trigger value is present, a command sequence is sent to all linked gambling machines. At the same time there occurs a final game in the gambling machines based on the command sequence. A rank sequence and a winning quota, respectively, is determined based on the predicted game result and the actual game result, wherein the rank sequence and the winning quota, respectively, represents a distribution key for the jackpot.