Hide Bonus Offers
#2 50% Up To $250 Visit Site Bovada Sports
#3 125% Up To $2,500 Visit Site BetUS
#4 100% Up To $500 Visit Site Everygame
#5 100% Up To $1,000 Visit Site MyBookie

How to Know You’re Not Getting Cheated by Rigged Slot Machines

| June 3, 2022 1:06 pm PDT
slot machines with big letters saying rigged?

For those of us who have gambled any significant length of time, the question “Are slot machines rigged?” has entered our minds. Perhaps just on the periphery of our thoughts, but honestly, why isn’t this infernal machine paying off right NOW?!

Sorry, had a moment there. The question is not as easy to answer as you might imagine, even though it can be answered with a single word—which I’ll get to in a moment.

If I built a car that had a maximum speed of 23 mph, would you consider that a rigged car? Certainly everyone else on the road would have something to say about it as they sped by, honking their horns and using sign language that I’m pretty sure is frowned upon by AMSLAN.

Back to my question: Is that car rigged? Or is it just designed to perform differently than you or I might prefer it? Maybe we should take a look at what factors are in play when IGT or NetEnt or even Aristocrat design a slot machine.

Slot Machines, RNG, and You

Inside of a slot machine

For the first 100 years of their existence, slot machines were mechanical in construct and operation. During the past couple of decades, they have become increasingly electronic in nature.

This brings us to the current time. We’d be hard-pressed to find a mechanical slot machine still in use at a brick and mortar casino. And we wouldn’t find a single mechanical “one-armed bandit” at any online casino—for reasons that should be obvious.

This change inadvertently protects players from rigged games. Mechanical gambling devices need mechanics, and the carburetors (or whatever those old one-armed bandits had inside) could be, um, adjusted.

The digital age has done away with that. Sure, you still hear rumors of rigging on necessarily mechanical games, such as if roulette tables are rigged, but even those are rare.

In any case, pretty much all slot machines in use today have the results of hitting the SPIN button dictated to them by a randomly generated number. That number—which is produced, oddly enough, by a special proprietary algorithm (fancy geek language for a computer program)—is called a random number generator (RNG).

The exact method any particular RNG uses to arrive at random results is closely guarded by the various slot manufacturers, but they all are very good at producing random numbers.

One of the only ways someone might be able to rig a slot machine would be to gain control of the machine’s RNG—which would be similar to grabbing the fan belt on a running car engine. Oh, and kids? Don’t try that at home, m’kay?

Volatility — It’s Not Just for Romance Novels

Volatility road sign

Volatility has many different definitions, depending on the context.

In human social interaction, it can describe a tempestuous relationship. In chemistry, it’s a number indicating how readily a substance vaporizes. On Wall Street, it’s the ratio of price variations of a stock over time.

In the gambling world, it’s an indication of how often a game pays out and to what degree. That means that a slot machine high volatility slot machine would pay out less regularly, but in higher amounts.

Some people prefer to win often, even though they know they’re still slowly losing money.

Others prefer periods of losing wagers that suddenly culminate in large jackpots. This machine is considered a high volatility machine.

Casinos and knowledgeable gamblers alike divide the volatility of games into three basic sets—High, medium, and low. Few casinos publish volatility figures, but you can make an educated guess by balancing the highest payout amount with the number of combinations on the reels that result in payouts.

For instance, a five-reel slot that pays out on virtually anything on any of three pay lines would be considered a low or even very low volatility slot machine. Incidentally, the presence of micro-wins on the pay table (wins that are less than the wagered amount) virtually guarantees the machine is low volatility.

It’s possible to calculate RTP even for progressive slot machines like hot drops slots. Well, maybe I couldn’t calculate it, but then, I’m in awe of the facility with which my wife calculates a 15% tip at restaurants.

One last point of clarification. Slot volatility is sometimes referred to as slot variance, but the term “variance” is also used to describe an entirely different phenomenon.

So to ensure there is no room for misunderstanding in this blog, I will only use the term slot volatility.

Variance — It’s What Happens While You’re Making Other Plans

Actual variance in any slot game is the ratio at which a win diverges from the statistical prediction. For instance, say a slot machine will hit a particular winning combination once every 100 spins.

You—discerning player that you are—just watched as someone else played that machine for 97 spins before getting frustrated and moving to a different machine.

You smile at your own cleverness as you slide into the still-warm chair at the machine. You drop a dollar in and hit the play button. Nothing. You do it again. Still nothing. Okay, maybe you miscounted, so you try it again. And again.

Soon, you’ve pumped fifty bucks into the machine a still no payout. WTF?

Okay, let’s calm down. Just like flipping a coin won’t come up heads every other flip, a slot machine’s payouts will vary in frequency over a given time period. They may even vary greatly. Over the lifetime of the machine, sure, it’ll pay off once every 100 plays.

But for the hour or two you’re sitting there, observing and playing, it may pay off five times during the first hundred sins, and then not pay off at all for the next 300.

Return to Player Doesn’t Mean What You Think It Does

Return to player graphic

Casinos are happy to publish its the RTP (Return to Player) percentage of their games. An RTP of 99.75% is very encouraging, indeed. But does this mean you can drop a hundred bucks into a dollar slot machine and at the end of that hundred, have $99.75 remaining?

It is to laugh.

Of course, you won’t have $99.75 left. You could have $3,865 left, provided you hit some of the bigger jackpots on the machine, or you could have nothing, simply because the machine never paid off, or paid off so poorly that you questioned not only your own luck but that of the people five or six branch back on your family tree.

And it might have been because you won 99.75 but played it all back in. It used to be that every win resulted in coins or tokens clanging into a metallic bowl affixed to the lower front of the machine.

This made it very easy to measure your actual winnings once your initial $100 was gone. What was in the metallic bucket was your RTP (or at least, a reasonable facsimile thereof).


The actual “official” RTP for any gambling game (yes, blackjack has an RTP, as does roulette) is a number calculated over the expected lifetime of a game. It represents how much of the money wagered on the machine across the span of time between its installation on the gaming floor through to the time it is loaded on a truck and taken out to the desert and buried in a shallow grave.

Ya know, I think I may be watching too many Scorsese movies.

As you may already have surmised, RTP has nothing to do with volatility. A machine with very high volatility may have an RTP of 95%–but so may a machine of low volatility.

Remember that volatility the ratio of how often wins occur over time, while RTP is the ratio of the size of total wins to total losses.

Pay Tables: The Fine Print of the Gambling World

Pay table graphic

The pay table on a slot machine is like the fine print on that 20-page purchase agreement for that condo in Boca Raton you signed yesterday. Sure, that fine print is probably important, and you’ll get around to reading it real soon.

Back to our muttons. Look at the lowest payout amount in the pay table. This is most likely the most frequent amount the machine will be paying. Now, look at the highest amount it will pay. That is, of course, your goal.

Between those two numbers are a series of increasing numbers that roughly approximate the degree of difficulty at hitting that combination.

Here’s the thing: While the payouts for any combination reflect the odds of hitting that combo, the payout is always less than the true odds would dictate. The difference between the payout and the true odds is called the house edge (or house advantage), and it is how the lights stay on in Vegas.

Just like Apple doesn’t spend $1500 building the newest iWhatever it’s going to retail for $1500 to gullible, er, discerning consumers like, um, some people we know. If it helps, think of the house edge as profit margin.

You can’t call a profit marign “rigging” unless you’re willing to accuse your local grocer of rigging the price on that six-pack of diet Fanta (ewww) he sold to you for more than he paid for it.

Top Tip
Note that while the RNG algorithm is not accessible to the casino operators, the pay table usually is. But differences in pay tables for the same game on different sites or at different casinos simply reflects the house adjusting its edge.

It’s not like they’re hiding it from you—the numbers are there for all to see. Just like that footnote on page 17 of your time-share purchase agreement. To coin a phrase, read it or weep.

How to Ensure You’re Not Playing a Rigged Slot Machine

There are several ways you can protect yourself from any sort of gambling chicanery, including the possibility that your favorite slot machine is rigged.

 Here are four of the best ways to ensure an honest gambling experience—before you make that sign-up deposit.

Cop stopping someone in a car

License and Registration Please

Go all Dragnet on the casino. Check out its license. Determine what country governs its actions, and then look at the restrictions that country puts on casinos. You want to make sure you’re dealing with a secure casino online by a legitimate authority.

No legitimate online casino should have a problem producing this information, and a visit to the registering country’s website should confirm the casino’s claims.

Get the Pedigree of Their Slot Software

Virtually no online casinos develop or run their own slot machine software. In fact, if they do, that’s a pretty good indication that things ain’t all kosher in Denmark. The most reliable online casinos are those that license slot software from one of the major players in the slot machine manufacturing business.

Using games licensed from heavy hitter developers like Aristocrat, NetEnt, IGT, and Bally is pretty solid proof that your selected casino is on the square.

All these companies have a very vested interest in the legitimacy and honesty of the best slot casinos online they provide to both brick and mortar casinos and online casinos.

Do Some Independent Research on the Site

“If you have nothing good to say about somebody, come sit by me.” The internet was invented to make that a universal reality, and now we all can gossip about all things, all the time.

Whichever search engine you use, try typing in the name of your selected casino along with the words “rigged” “cheat” and “scam”.

Bear in mind that simply because “winbiglycasino.com” and “scam” generates a few hits, that doesn’t mean that winbiglycasino is a scam. Read the comments made on those search results. See why the commenter feels like they were scammed.

You may find substantive proof that there was, in fact, some scamming taking place. Or you may find that the commenter misunderstood winbiglycasino.com’s terms and conditions.

And don’t forget to check the various blacklisted online casinos to further refine your search.

Trust Your Instincts

If you’ve already satisfied the above four guidelines—and you’re still unsure—it’s time to trust your own judgment. If everything looks okay but you still have a nagging suspicion about the online casino—don’t sign up. Don’t make a deposit.

Instead, find an online casino that has all its papers in order, and which also makes you feel like a valued patron and not just another calf in the chute. This may be your first rodeo, but you don’t have to tell them that.

Okay, Now Answer the Question: Are Slot Machines Rigged?

Twilight Zone slot machine

To be succinct (if only for the novelty): No.

Just like pop-up bars, there may be pop-pup online casinos that are there today, gone tomorrow (along with your deposit, of course).

But if you’ve vetted all your most secure online casinos as I’ve suggested, and selected one or two that meet all of the requirement, you won’t be dealing with them—and you won’t have to worry about whether or not the casino’s slot machines are rigged.

Remember that although you’re very unlikely to play a rigged game at any of the vetted casinos we feature here on GS, you should bear in mind that you can still lose. Be sure to budget your bankroll, never bet more than you can afford to lose, and above all, stay away from slot machines that follow you up to your room.

Slots aren’t the only casino game some people think is rigged. Here’s a look at why Blackjack isn’t rigged, either.

5 Reasons Why Online Blackjack Isn't Rigged

Is online blackjack rigged? Before I answer that question, let me begin with a simple statement of fact: Nobody thinks the game is rigged when they’re winning. It is our impressive gambling acumen that makes us a winner, amirite? Luck is for chumps. So,...

Read More
J.W. Paine
J.W. Paine

J.W. Paine is one of the most experienced writers at GamblingSites.com. He's written for television and the printed media, and is a published novelist (as Tom Elliott).

Paine loves writing about Las Vegas nearly as much he loves living here. An experienced gambler, he's especially familiar with thoroughbred horseracing, poker, blackjack, and slots.

More Posts by J.W. Contact J.W.



Back to top