The Megabucks three-reel slot that paid the world record jackpot of more than $39 million has about 50 million combinations. With 100 stops on each of three reels, there are 1 million combinations. The change to virtual reels enabled programmers to make the reels to behave as if they had any number of stops.
The sheer number of possibilities makes the math that goes into slot machine odds more complicated than on table games. The number of winning combinations and the payoffs per winner work together to determine a game’s odds.
There also is an open field for game designers to assign how much each winning combination pays. There are thousands, and sometimes millions, of reel combinations. Slot machine odds work in a similar fashion to the roulette example, except there are many more possibilities on the slots.