So far, we’ve established that the results of modern slot machines are programmed to be random. However, as with other casino games, the odds of slots are set in a way that gives the house its edge. Casino games make money for the house by paying out less than the true odds of the winning bet. With table games, this can be quite simple. Let’s take European roulette as an example. With numbers 1 through 36, plus a single 0, the true odds against any particular number are 36 to 1, but the casino pays single-number winners only 35 to 1.
Slots odds work in a similar way to our roulette example, except there are several more possibilities on slots. Because of the RNG software, there are thousands, and often millions, of reel combinations. It’s also up to individual game designers to determine how much each winning combination pays. The number of winning combinations and the payouts per combination work together to determine an online slot’s odds. But the vast number of possibilities makes the math of slots odds more complex than table games odds.
The player also doesn’t know how the game was designed. Therefore, it’s hard to quantify the odds of modern slot machines, whereas it was easier to figure out the true odds of an old-school mechanical game. You could have calculated your odds based on the number of reels and symbols per game. For example, a slot with 3 reels that holds 20 symbols per reel would give you a 7,999 to 1 chance of winning.
So, is there any way we can choose slots which offer better returns than others? And how can we know the house edge of a specific slot game? This is where RTP comes in, which we’ll talk about next.