When does the Random Number Generator on a slot machine stop? When you hit bet? Or, spin?

[SteveBourieOLD]

We received the following question:

This question is for Steve Bourne. On a dollar slot 2x3x4x5x my dad hit the top symbols( 3x4x5x). He hit the one credit button then the spin button. Does the random # generator lock in when you hit the 1 credit button or when you hit the spin button. Had an argument at a casino. I think it’s the spin button. The other guy says no. He says as soon as ya hit that 1 credit the pay or no pay is decided. I told my dad be glad you hit $2,400 on the 1credit spin because had you hit max or the credit button 2x the timing difference would made a different outcome. The machine was progressive and max $2 bet pays the $78,000+ progressive. Thanks William!!

[SteveBourieOLD]

We received the following question:

This question is for Steve Bourne. On a dollar slot 2x3x4x5x my dad hit the top symbols( 3x4x5x). He hit the one credit button then the spin button. Does the random # generator lock in when you hit the 1 credit button or when you hit the spin button. Had an argument at a casino. I think it’s the spin button. The other guy says no. He says as soon as ya hit that 1 credit the pay or no pay is decided. I told my dad be glad you hit $2,400 on the 1credit spin because had you hit max or the credit button 2x the timing difference would made a different outcome. The machine was progressive and max $2 bet pays the $78,000+ progressive. Thanks William!!

Here is my initial answer:

It is my understanding that the RNG will continue to operate until you push the spin button, or max bet button, and then it chooses a combination. I will, however, check with a fellow gaming writer to confirm it.

[SteveBourieOLD]

And here is the follow-up answer:

Below, in bold print, is the answer from my fellow gaming writer, John Grochowski. It seems that the most likely outcome is that button pushed to start the reels spinning is what determines when the RNG stops. It could be different, based on the manufacturer, but most of them program it this way.

So, since your dad pushed the one bet button first, that did not stop the RNG. When he pushed the spin button that is when the RNG stopped. Therefore, the result would have been different if he had bet max coins (unless he happened to stop the RNG at the exact same micosecond the get the same result. .A very unlikely event!).


I think your response is fine. I think I'd add that different manufacturers can approach the issue in different ways. The common way is for the the RNG to set its number when you hit the button that will start the reels spinning, regardless of whether it's a max bet, spin reels or repeat bet button. But slots can be programmed so that the RNG fixes its result after the first indication that you're actually going to play -- when you hit the bet 1 button, the max bet button or the repeat bet button.

Either way, the result is as random as humans can program it to be, and it makes no difference in the payback percentage.

There is a potential difference on some video slots that give you the option both to select a number of paylines to play and a number of coins to bet per line. On some games, you have an option to change those right up until you hit a spin reels button. On such games, you're not committed to actually playing that spin until you hit the spin reels button, so the RNG keeps running until you hit the button that starts reels spinning.

That's a different situation than a 3-reel slot where if you hit bet one, the reels don't start spinning, but your bet is registered. You can either hit spin reels at that point or you can hit bet one again to add to your bet, but one you've hit bet one the first time, there's no going back. You're committed to playing that spin, and some manufacturers may choose to have the RNG set your result at that point.