Do Casinos Adjust their slot machines to win more?

Playing the slots on a bad day is not fun. We’ve all been there at least once or twice. If you’re going through it now, you might be thinking — has my luck left me, or is something else amiss here?

Don’t worry; you’re not the first to have these doubts.

One of the oldest urban legends among players says casinos interfere with their slot machines’ payouts and odds. But is that possible, and if so, how do they do it? You’re in the right place to find out.

This article will clarify the mystery behind the randomness of slots once and for all. Keep reading to learn all you need to know.

Mechanics of Slots

To answer the burning question of whether casinos adjust their slots, we must understand how these games work. So, let’s lay the foundation first.

Image of Slot Machine Reels

The slots we know and love evolved from an older, well-known game. Original slots were standalone machines with three mechanical reels, each bearing ten symbols. The reels were attached to a physical lever the player was supposed to pull to set them in motion. These reels would spin for a while thanks to kinetic energy and then come to a random stop.

Because the system was entirely mechanical, the winning odds of these games had to be set mechanically, too. The machines’ randomness was achieved through an invention called a random number generator (RNG). Casinos used to hire a separate workforce to install and adjust the RNGs that kept their slot machines random.

However, true randomness was impossible to achieve. RNG machines had a limited number of settings, and someone had to instruct the workers on what setting to use each time. Most often, the casino operator was the one to make that decision. So, technically, casinos were more than able to rig their slot machines if they wanted to.

Since then, slots have changed dramatically. The advancement of technology has had a direct impact on how these games work. Slots evolved into digital systems in the late 90s and early 2000s. They transitioned from 3-reel, 10-symbol machines into much more complex video screens with several reels and up to 256 symbols.

As opposed to mechanical ones, the moving images on modern slots are not attached to any physical levers. Instead, they’re controlled by a computer. You start the game by pressing a virtual button, and the computer determines the outcome at that very moment.

So, how does this system affect the odds and payouts of slot machines today? Can casinos adjust modern slots too? The following section provides the answers to these questions.

Image of Slot Machines in a Casino

Is It Possible to Rig a Modern Slot Machine?

The short answer to this question would be yes. Computer operating systems that control the odds of modern slot machines can be adjusted. Technically, someone skilled in the field can access them remotely or onsite and make whatever changes they desire. Nevertheless, just because it’s possible doesn’t mean it happens. Here’s why.

Most of the US has strict gaming laws. Every state where casino gaming is legal has a regulatory body responsible for licensing and monitoring the casinos within its borders. The same goes for online gambling operators— if they don’t fall under the jurisdiction of the state, these casinos are regulated and licensed by offshore gambling authorities. 

Either way, gambling licenses are not easy to obtain. The procedure requires gambling venues and sites to provide extensive evidence that their operations are honest and fair. Among those pieces of evidence, regulatory agencies often ask casinos for proof they’re obeying the required slot RTPs limits and publishing the payback percentage of their slot machines.

Image of RTP on Slot Machines

For those unfamiliar with the term, RTP stands for Return to Player. It’s a metric that expresses how much of a slot player’s money the casino returns to them over time. Let’s look at an example to make this clear. If a slot has an RTP of 95%, the casino pays back $95 for every $100 that players bet. The remaining $5 goes toward the casino’s house edge.

Limits on RTP give casinos little wiggle room. They risk paying high fines and losing their gambling licenses if they’re not compliant with the rules. While the former might not seem as harsh to some, the latter is a risk that casinos can’t afford to take. So, you can be sure that they don’t tamper with the odds.

What Makes Modern Slots Random?

Having read everything so far, you might wonder what or who controls slot machines’ odds and payout. What makes these games random? The answer to that is, once again, RNGs.

Image of RNG on Slot Machines

Like slot machines, RNGs also have evolved. They’re no longer the machines from the olden days mentioned earlier.

Today’s RNGs are computer programs designed to ensure that every spin of the slot machine’s reels is random. To do that, they use an algorithm that creates random sequences of numbers. The numbers are assigned to symbols you can see on the slot machine’s screen. The machine cycles through numbers at an incredibly rapid rate and stops at a random one. The program notifies the device, and it displays the outcome to the player.

There’s no way of telling how many and what combination of numbers corresponds to what symbols. The speed with which the RNGs go through the numbers, even when the machine is idle, makes it impossible to predict any patterns. The program also doesn’t record its previous stops — each is an independent event. You could go through 30 spins without a win and then land a win on each of the next ten.

The combination of these factors makes it impossible for many of the gambling community’s urban myths to be true. There’s no factual evidence for the existence of cold, hot, or loose slots. RNGs ensure these games always hit randomly.

Third-Party Audits

Casinos nowadays go a step further to show that all their operations are fair. They partner with various third-party organizations that perform internal and external audits. Internal audits comprise RNGs authenticity and functionality testing procedures. Specialized RNG auditor companies perform mathematical analyses and payout evaluations of all casino games and provide reports on their findings. These assessments take place regularly — on a monthly or yearly basis — depending on regulations.

External audits involve a procedure where an independent public accountant revises casinos’ financial statements. They ensure each casino’s financial activity is reflected in the statements provided. Casinos offer these reports for review to gambling authorities.


Do casinos tamper with slot machine odds and payouts?

Not really. Slot machines in casinos have a built-in house advantage because that’s how the casinos turn a profit. However, these gambling venues are legally prohibited from making the odds of these games unfair. Regulatory bodies impose limits on casino each game’s average return. So, tampering with slot machines’ randomness would put casinos at risk of losing their gambling licenses and getting in trouble with the law. 

How do casinos ensure their slots are random?

Casinos use special computer programs called random number generators to make their games random. The programs create arbitrary sequences of numbers, assign them to the symbols on the slot machine’s screen, cycle through them at a rate of thousands per second, and make unpredictable stops. These stops determine the outcome of the game.

Is there such a thing as loose or hot slots?

No. Thanks to the workings of RNGs, no slot machine’s payout patterns can be predicted. The only way a machine can be called loose or hot is if it has an exceptionally high RTP.

What is the highest in RTP online slots?

RTP percentages vary between the games. Some of the highest ones you can come across online reach 99%.

About the Author

Author Hi all! My name is Jayson Peter, and I am the Chief Editor here at Casino USA. I have always been a huge fan of casinos, but I noticed that there are not a lot of websites out there that discuss the gambling industry in enough detail, so that’s how the idea for was born. With my extensive knowledge of the industry and the help of my team, I am ready to give you an insight into the exciting world of casino gambling in the United States.