Slots machines generally have three or more “reels,” each of which has a number of symbols. While physical slot machines may have 20 or more symbols per reel, digital technology allows them to have many more—some have 256 virtual symbols—with millions of possible combinations. The combinations of symbols that pay out if you bet on them are called “paylines.”

Slot machines contain random number generators that can generate thousands of numbers per second, each of which is associated with a different combination of symbols. Whether you win or lose is determined by the random number generated in the exact instant you activate each play—if it matches a payline, you win. Since each spin is independent, random and unrelated to previous or future spins, it’s impossible to predict what will happen on each play.

There are many different kinds of slot machines. Some allow you to choose how many paylines to bet on per play, and how much you want to bet. Before you put your money in, figure out the cost per play, the odds, the paylines, the return to player, and anything else that will help you make the right decisions for you. Look for pay tables on or near the machine that explain everything you need to know.


The possible payouts and the odds of winning depend on the machine you’re playing, the paylines you choose to play, and how many credits you wager. 

Machines that cost pennies to play might pay out small prizes relatively often. Others cost several dollars per play, but offer bigger jackpots and higher odds. For instance, for the I Heart Triple Diamond penny machine, the odds of winning a prize are 1 in 12, but the odds of winning the top prize are only 1 in 649,400. 

No matter what machine you decide to play, the odds always favour the house. This means that over time, it’s more likely than not that you will walk away with less money than when you started.


While machines can be programmed to pay out at higher or lower odds, a typical average house advantage for slot machines is 8%, meaning the average return the player is 92 percent. That makes slot machines less favourable than tables games such as fortune pai gow poker, blackjack and roulette, in terms of return to player.


Game House advantage, with optimal play
Baccarat 1.06%
Blackjack 0.5%
Craps 0.8%
Fortune pai gow poker 0.5 to 2.5%
Poker 2 to 3.5%
Lottery 50%
Roulette 5.3%
Slot machines 8% (average)


Playing longer doesn’t improve your odds of walking away a winner.

Persistence doesn’t pay off. Each play on a slot machine is independent, unpredictable and unrelated to what happened on the previous play. A machine is never “due for a win” and they don’t “go cold” after a win either.


Soon after you leave a machine it wins a jackpot—that doesn’t mean you would have won if you kept playing.

Future wins on a machine are completely unrelated to what happened when you were playing. Because random number generators determine the outcome of each play, the results of each play are totally independent from what happened before. Outcomes depend on what random number is generated in the exact instant a player presses play or pulls the lever. 


Machines that are furthest from the aisle do not pay out more because they’re played less often.

How often a machine is played has nothing to do with how likely it is to pay out on the next play. Payouts are determined by the pre-set odds of the machine and the unpredictable results of the random number generator inside. 

You cannot improve your chances of winning at most slot machines.

Most slots are games of chance, based on the random number generator. For some machines, bonus games offer you a chance to influence the outcome by interacting with an arcade-style video game. While skill may be a factor, the random number generator usually determines whether you even get to play the bonus game and the amounts available to be won—so chance is still a major part of the deal.