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Are Free Spin Bonuses on Vegas-Style Slots Predetermined?

Money Galaxy Dragon's Return by Konami
Written by Joshua

Previously on the site I wrote about bonuses on non-RNG games and whether they’re predetermined. On a forum recently I saw a discussion around Vegas-Style (also known as Class III) slots and whether specifically the free spins bonuses on these games are predetermined.

STATUS: The expectation is most aren’t. But they can be, at least a few are suspected to be. So the status is mixed.

Both predetermined and RNG-driven bonuses are allowed under most rules and regulations for game design. It’s one of many, many regulations that exist. For instance, here’s one for Nevada around the use of bonus reels that differ from base game reels:

In the case of a video reel game where reel element weightings are changed due to free or bonus spins the gaming device must explicitly state in the help or award screens that different reels are used during the free or bonus spins, and do at least one of the following:

1. Alter the appearance of the reels (i.e. change the appearance of the symbol or change the background color of the reel strip); or

2. Explicitly state on the game screen that “bonus reels are in play”.

Nevada Gaming Regulations

This allows manufacturers to offer different odds for bonus spins; bonus spins could be more (or less) lucrative in the free spins, but it helps them balance out the weighting of bonus spins to make sure the overall expected math works.

Given the ability to do this, and the fact that Vegas-style slots already use an RNG, it’s believed that most free spins bonuses on Vegas-style slots use the RNG. But that doesn’t mean they all do, or have to.

There’s some bonuses that are either partially or fully predetermined. Some older Quick Hit machines, with the 20 options to pick from, don’t show you the other choices when you match three. So those could be at least partially predetermined.

On the other hand, those that let you pick which bonus option you want, like Scarab, Golden Egypt, and other volatility choice bonuses are letting you choose an outcome that’s not determined yet. Similarly, a game like Wheel of Fortune, where the wheel spin outcome is decided the moment you hit spin. So the bonus couldn’t be predetermined because there’s user input that factors in.

As you can see, it’s a complicated question, and since manufacturers don’t display the information in the machine, it’s not a clear answer either. But in case you’re worried that a predetermined bonus is somehow less lucky to pay big, the math for either choice will see to it that the proper distribution of bonuses are awarded regardless of approach, and those handpays are lurking in there somewhere.

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.

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