According to a process for operating a slot machine that works as a roulette wheel, the gambler determines the amount of the stake by introducing coins then by pressing selection keys. A microprocessor determines the result of the game by means of random algorithm. When the chosen number is hit, the microprocessor instructs the coin distributing unit to eject the main prize. When a chosen number is hit, the microprocessor drives another processor with a random generator. The random generator determines, depending on a written algorithm, a gain multiplier which is multiplied by the amount of the stake on the number that was hit. The payment unit is then instructed to distribute an amount in coins which corresponds to the product of the stake on the number that was hit and the gain multiplier.