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Are Slot Machine Bonuses Predetermined?

Dancing Drums by Shuffle Master and WMS progressive pick
Written by Joshua

One of the more common questions about slot machines that comes up is if a bonus is predetermined or not. If it’s predetermined, any picking or spinning is just visual eye candy for an outcome that’s already been decided, and some aren’t the biggest fans of it.

Status: Some are, some aren’t.

Since that’s a very unhelpful answer, let’s take a look of traits that can help you determine if a slot is predetermined or using the RNG to decide the outcomes in real time. And before we do, let’s rule one trait out that has nothing to do with the nature of the bonus you’re playing.

When Slots Reboot

One thing you may notice if your slot machine resets, or if there’s a power interruption or other issue that may force your bonus to recover and restart is that you’ll get the same choices and spin results up to the point of the interruption. Some see that as a sign of it being a predetermined bonus. In fact, by design, slots keep track of a bonus’s progress so it can restore to the exact point of a failure if a machine get reset.

One reason for this is pretty simple: If players knew they could start a bonus over and get better results by causing a machine to reset via a power issue or some other means, it would be a way to manipulate a machine. Beyond this, some slot manufacturers have a way to replay the bonus, so for handpays or other scenarios of importance they can show off what happened for marketing purposes. As you can imagine, not a lot of information needs to be recorded – the game can replay the same RNGs for random bonuses as it could a predetermined one.

With that out of the way, let’s discuss the signs of a pre-determined bonus versus a random (RNG-driven) one.

When a Bonus is Predetermined

First off, we need to immediately rule out virtually all machines that aren’t Vegas-style (Class III) slots from this exercise, because the bonuses will be predetermined.

  • Bingo (Class II) Machines: The bingo game determines all payouts, including bonuses, so once the outcome is determined from the game, everything else is just window dressing.
  • Historic Horse Racing Machines: Similarly, since the outcome of the payout is determined by the horse race that is selected and played out, the bonus is already determined since the final payout is already decided.
  • VLT/VGMs: The first time I ever went to a New York Lottery-driven casino (Empire City Casino in New York) was also the first time I met Brian Christopher. We both noticed that Quick Hit had the standard picking bonus to determine your free spins, but failed to show the other options. That was when we realized that, because of the nature of the VGM games pulling the outcome from outside the machine, the bonus was predetermined. That said, there are some VLT/VGM machines that work with random number generators (RNGs) that are considered VLTs; those would be exempt from this category and potentially have predetermined bonuses.

Manufacturers choose not to share the details too often about whether it’s definitely a pre-determined pick or not, but here’s one other way you can likely know a bonus is pre-determined, many game designers have said:

  • Picking bonuses that don’t show the other outcomes: This is common in the 88 Fortunes-type machines where you pick a progressive, for instance. The general rule of thumb is if you don’t see the other options, it’s definitely predetermined.

When It’s Likely Not Predetermined

A few areas where bonuses likely play out with the RNG running just like a real bonus:

  • Games where the unpicked options reveal: The counterpart to the above, if you see the other options, it’s likely not predetermined. I have seen some examples of games where you can clearly tell things are weighted progressives, but play out like they’re not, such as Everi’s “Smokin’ Hot Stuff Wicked Wheel.” It shows three of everything as pickable but based off the slot channel gameplay shared it is a weighted progressive pick like all of them.
  • Free Spins Bonuses: Generally speaking free spin bonuses on RNG-driven machines will play out using the RNG; you will generally see something like “Bonus Reels in Play” on the machine to confirm this. This allows the manufacturer to use bonus reels to determine if a bonus should have different types of outcomes to be possible, like a more frequent progressive or better line hits, for instance.

    Since some jurisdictions require a visual difference when you have bonus reels, this is why you many time see different backgrounds, reel symbol differences (like the words Free Games on old Quick Hit machines during a bonus) and other visual signs that something’s happened.

    Generally the next spin is determined in free spins when the last spin is fully resolved. So speeding the game along does change the timing (and outcome) of the next spin.
  • Bonus Volatility Choice Machines: RNG-driven games that let you choose the bonus type, such as bonus volatility, or credits vs. spins like on Konami games, likely don’t know either outcome until you make your choice (and in the case of spins, until each spin resolves). Since you can always switch from spins to credits on Konami, for instance, the RNG wouldn’t be hit for an outcome until you confirm you want a credit prize. So that bonus wouldn’t be predetermined, as it is triggered by user choice.
  • Spinning the Wheel: On games like Wheel of Fortune, the wheel spin amount is decided when you hit the button.

Does it Matter?

Some people feel predetermined bonuses are somehow unfair. The reality is that RNG-based games use math and the paytables to determine what a game will pay over time, including in a bonus. A predetermined bonus will pay a certain amount over time. As a player we can’t know what changing our timing will truly do on an RNG machine.

As such, knowing whether it’s predetermined or not really makes it a mental exercise, another superstition for slot players to get excited about. In the long run, presuming you have two machines with identical payback and one is an RNG-driven bonus and one predetermined, you’ll get the same payback in the long term.

What’s your favorite bonus game? Share in the comments!

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.


  • Do you tubers make their money on slots or on their videos. Do they ever lose you never see a losing video which gives viewers false hopes when they go to a casino expecting to win on the same slot play scenario

    • No YouTuber makes money playing slots – slots are designed to make money for the casino over time. Some channels with a large enough audience can cover their expenses and beyond through non-slot revenues such as video ads, merch and so on, but many don’t recoup the money they are spending.

      As far as winning vs. losing, videos with mostly losses don’t get as many views – players don’t like watching other people lose either. So they give what people want. Viewers’ false hopes is an understandable issue, but as players we need to watch out for ourselves and that means being realistic about what is possible on a casino trip.

  • I would say that even if the remaining unpicked items are revealed “after the fact” (after the bonus has been awarded) during the jackpot feature, that the bonus itself could have be predetermined. Anyone with computer programming aptitude would be able to write this function of “insert remaining list items [unpicked items] into empty slots/spaces” into the programming code fairly easily. This is also demonstrated by the fact that there are Everi Hot Stuff Wicked Wheel machines that are Class II/bingo machines, which do reveal unpicked items during jackpot features AND functions on “pre-determined” slot pulls.

    • Hi JV! A couple of important points: Class II/Bingo machines aren’t slots, so the rules governing them would be treated differently. However, you managed to name an example of even a Class III Vegas-style slot which bucks the trend and reveals a predetermined bonus. I wrote about that here previously. And there are at least a couple of other machines, also by Everi, that does this. These appear to be by far the exception, and I don’t know that Everi’s even doing this anymore. But it is a fair thing to note that the reveal/not reveal aspect is not universal. And while technically it’s not a huge leap to do this, most manufacturers opt not to do this.

      • Hey Joshua just got back from a Carnival cruise and played some slots , with that being said I’m not at all techie lol my boys are I’m 65 yrs old and completely over my head tv remotes are evil to me lol my question is I was playing a slot and was alternating bet 88- 8.80 from lowest to highest I would play the lowest when the bags of money where at there lowest amount showing and then when the bags grew to larger amounts I would play the higher amount and would hit the higher bonuses it work out I took 200.00 to 1750.00 hitting bonus after bonus. Had a to leave to eat and came back after and couldn’t get it to hit a bonus does it get out of reythem are was that just the luck of the draw

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