Myths vs. Reality Slot Payback

Do Casinos Change Payback Based on Day, Time or Specific Situations?

Payback Percentage screen
Written by Joshua

One of the most difficult casino urban legends that goes around is that the casino is tracking what you’re playing and adjusting the odds on a machine, or they raise/lower paybacks based on time of day or during special occasions.

Status: Very, very unlikely; in most cases definitely not, anyway.

Slot Machine Basics

Starting with Vegas-style (Class III) slots, the design of the games has always made changing paybacks difficult. Older slot machines would have their paybacks set based on a specific chip placed inside the machine. If a slot was getting changed to a different payback, a different chip would need to be installed; same if the machine was getting reset into something else.

A study conducted in 2009 of a few IGT games by University of Waterloo researchers examined the way slot machines were designed and how they achieved their given payback percentages.

The move to more software-driven approaches moved the payback selection to a software choice within the game’s configuration. The payback choices are built in to the game, and the casino chooses a payback level that fits with their goals for how much they want to earn off a given denomination’s games.

Some think that a software driven approach means casinos are always tinkering. However, Kevin Sweet, VP of Slot Operations and Marketing at Cosmopolitan, says the systems that would help casinos manage that have never worked well:

As for machines being changed… The holy grail of slot technology 10 years ago was the deployment of “server based gaming”, where we’d be able to update games on the fly. That was more of a pipe dream and never really materialized. The most common example of why this was going to be so great for casinos was that on Friday and Saturday we’d be able to remove the penny denomination from our games, forcing our guests to bet more because we’re so busy. But the truth is, it never worked and we’re never that busy. No one is doing that. Basically, once a machine is set up, that’s how it stays.

Kevin Sweet, VP of Slot Machines and Marketing at Cosmopolitan Las Vegas, sharing his views at Vegas Fanatics

Many states have regulations that when a machine is changed, it needs to be reported as a new game. Some have rules about how long a game must be idle before and after. Many casinos have machines adjusted by multiple staff working together so that there’s an audit trail and not one person responsible whenever a machine is adjusted. And anyone who has seen a slot machine reboot after a change knows it is not something that bounces back right away; a whole verification process takes place before a single bet can be made on the machine. In fact, the average slot machine in Nevada takes at least a half hour to update and reset, so most casinos are making changes rarely, mostly when rolling out new games or moving machines around periodically.

A casino operator can generally improve their fortunes more rapidly by simply swapping out poorly performing games vs. tinkering with the payback. And remember those paybacks are achieved across millions of spins over time, not a night or a weekend; a casino could lower payback by one percent and not see a penny in benefit because they had a higher than average number of jackpots – that’s the random number generator in action. But they could see their fortunes improve by taking a machine that’s been idle awhile and dropping in a new game that more people want to play.

Outside of Vegas-Style Slots

What about machines where the outcome is determined outside the game? Theoretically, a casino could choose to, say, have Bingo games with lower payouts and less winners, or a state-run program that reduces the payback percentage with the video lottery terminals.

In the case of Bingo games on Native American casinos where there isn’t reporting of paybacks, that’s certainly one outcome. But most casinos aren’t going to go crazy lowering paybacks because if you feel like you can’t ever win, you’ll eventually stop going. Casinos count on some positive experiences in gambling to ensure return visits. Plus with the amount of competition out there increasing, people will play where they feel they’ve got a better chance, and so casinos have to work within that framework too.

For state-operated VLTs like in New York, laws set the minimum payback threshold (in New York it’s a surprisingly high 90 percent minimum, even on penny machines). Plus the machines are tied to a system that has a set number of outcomes that need to be worked through to achieve the payback. As such, switching it wouldn’t be instant, and likely would take some time, and the amount to be gained not very significant given the high floor on paybacks.

In conclusion, it’s very unlikely casinos are constantly tinkering with paybacks. There may be decisions to go a certain direction over time, but there’s no overnight raising or lowering of paybacks across a casino floor in a weekend.

About the author


My name is Joshua, and I’m a slot enthusiast who works in tech as a marketer by day, and dabbles in casinos periodically during off-times. Know Your Slots will reflect my interests in understanding the various ways you can play slots, travel, casino promotions and how you can get the most out of your casino visits.


  • I have been playing on a machine several times and lighting it up, then I’d notice a slot attendant walk up and put their card in a machine that has no issue or need for them to inject the card, and go from hitting every other spin or within 5 spins getting a 3x payback or even a 110 percent return, to losing 150-300 dollars on 300 max bets without getting another 100%return.

    I even called this little weasel looking punk at soboba in California out on it, and from then on I never hit another jackpot. (Was my goto spot from 2013 to 2016? Started paying attention and figuring out stuff in 2015) and to further implicate such behavior I noticed the last few times I went after the incident, they were hovering around me and doing the card thing every block I went to. Soboba in my opinion defintly controls their slots

    • No slot manufacturer has developed a slot that can have its payback changed just by inserting a card. The card reader isn’t even a core feature of the slots – they’re added on based on the casino’s need or request. I learned recently there are more than 200 companies that make player tracking software, and a casino can choose to install any of the 200 – but none can control the slot’s outcome. Slots can even function without a card reader. As such, it’s perception bias/coincidence this was happening to you.

      Over time, all games have a house edge that will take away money. It’s just how the math works. Short term wins and losses are just variance that slowly get smoothed away by more and mroe spins.

        • If you’re talking about regulated online slots, like those real money casinos offered in specific states and generally linked to the physical casinos of that state, it would be the same – in fact you can even see the payback percentage in the pay table of many online slots in the state-regulated sites. Those more murky, grey area offshore casinos based in countries with much more lenient regulations… it’s a lot less certain.

Leave a Comment