Slots - RNG Timing

You are playing a three-coin slot machine. You only are playing two coins at the time. The jackpot is hit. If you had been playing one coin, or if you had been playing three coins, would it still have gone off at that point?

Ronald from Maryland, USA

If you had put in one or three coins the outcome would likely have been entirely different. The machine is constantly drawing random numbers and the numbers that were drawn at the moment you spin the reels determine the outcome. So, if you had played fewer or more coins you would have spun the reels at a different moment and thus the outcome would have been different.

Hey Shack I hadn't been to the site in awhile and I just wanted to compliment you on the new sleek look. I know you initially wanted to stay away from the banners but they do help pay the bills eh?

Congratulations also on the new gig with Casino Player, I enjoy it the site and your occasional posts on bj21. As someone who works in the industry, admittedly not slots, I was under the impression that the more recent slots have the RNG stop the moment the first coin drops, so it really doesn't matter if you play 1,2, or 3 coins -- the symbols will line up the same. Have I been misinformed? According to your previous answer I apparently have. Keep up the good work and I'll stay in touch, thanks and best wishes.

Dave Simon from USA

Thanks for the kind words Dave. You're right that it was the money that finally made me accept the banners. It is my understanding that when the player presses the button to spin the reels the random numbers are drawn at that instant, which determine where the reels stop, and ultimately what you win. The number of coins bet does not matter.

How many numbers does the RNG (Random Number Generator) pick for each spin in a slot machine? Is it three numbers (1 for each reel) or is it 1 number that's mapped to a unique combination of symbols for all 3 reels?

Vincent from Chicago, Illinois

The machine picks one number for each reel.

This is a great website!. FYI - A guy missed the Megabucks jackpot (7.9M) yesterday because he had just two coins in. To the best of your knowledge, when does the RNG stop and determine your outcome? If it stops on the first coin, then he blew it. If it is on the last coin, he could have had an entirely different outcome. My guess that the stop time is set by the individual manufacturer, and there is no regulation telling him when to do so. Just wondering if you knew different.

Andy from Bloomfield, USA

Thanks for the compliment. The outcome of the game is determined when the player initiates the spin. The game is constantly drawing random numbers, even when not played. The random numbers chosen at the moment the button is pressed to spin the reels determine where the reels stop, which determines what the player wins. So, if the player bet three coins he would have pressed the button at a different moment, causing a different outcome.

Have you noticed when you look sideways past the right reel on IGT games there are 4-5 counters inside the machine labeled "coins in, coins out, jackpots" or similar wording? I was just wondering what your experience with the counters was. Is there any way to get helpful information from those? Thanks for your time.

Chris from Madison, USA

No, that information won’t help you at all. Your odds are always the same on every spin, regardless of the counters.

I have heard it is illegal for a slot machine to deliberately have too many near misses. Can you tell me what you know about this?


To answer your question I asked a well connected gaming consultant and he said Nevada regulations state that one stop on a reel can not be weighted more than six times more than either stop next to it. So if a jackpot symbol were weighted by 1 and both bordering blanks were weighted by 6 then there would be 12 near misses for every one time the reel stopped on the jackpot symbol. This would be the maximum allowed near miss effect. My own results detailed in my slot machine appendix 1 back up this theory well. The red double seven was the highest paying symbol and I saw the blanks above and below it about 5 to 6 times as often:

Double Strike Actual Results

Symbol Reel 1 Reel 2 Reel 3
Blank 250 248 291
Double red 7 52 51 55
Blank 259 292 262

The same source said that New Jersey and Mississippi likely have adopted the Nevada regulations.

This is not a game theory question, but I figured since you answer dating questions you might handle this. I had a dream recently where I sat down at an open slot machine. I was getting my player’s card out of my pocket when a guy came up from behind me and put money in the machine. I told him it was my machine and hit the cash out button and gave him his ticket. He said he had his eye on the machine and since he had his money in first it was his machine. I turned to call a slot attendant and while I was doing that he put his money in again, pushed the button and hit a jackpot. In my dream we then had an argument over who gets the money, the person who clearly had the machine and intended to play it or the person who unsolicited put the money in the machine. I realize this is a bizarre situation but who do you think would win the argument?

Bill from Columbia, MD

My understanding is that the person who is pressing the buttons gets the money. I asked Brian, who helped with the last question, about this. Here is what he wrote, which I agree with.

In the scenario described, the person who put in the money and pressed the buttons would receive the jackpot.

What I find interesting about this question is the paradox that in all likelihood, the jackpot never would have occurred without this chance encounter.

As you know, the random number generator in the slot machine is continuously working even when the machine is not in play. So even though one patron feels cheated, their run-in ultimately led to pressing the spin button at that exact millisecond when the RNG was on the winning combination. So, if one patron had acquiesced, there is never a jackpot to fight over.

I have used your site to knock down myths and betting systems with many friends and your proofs always win the day. On the Pink Panther (and some others) there is a bonus round that presents a screen with pictures from which to pick. Behind some are coin amounts and others have a symbol that ends the bonus round. Once you are presented with the bonus board the placement of the symbols cannot be changed, can they?

Jack from Rockaway, NJ

Thanks for helping in the fight against betting systems. First let me say that I have never worked for a major slot machine company and don’t have direct knowledge of this. However, I know many people in the industry and those I trust pretty much are in agreement on this topic.

That said, it is my understanding that in all forms of electronic games, including video slots, video poker, and video keno, the outcome is usually determined the moment you make your decision. Meanwhile the possible outcomes are constantly being shuffled, thousands of times a second. I can’t speak for every slot machine but I believe that with the major U.S. slot makers the outcome is not predestined but depends on the exact microsecond you press the button to make your play.

First, love the site, very informative! Background: When using a Random Number Generator (RNG) to determine certain payouts for a finite set, such as 1 million lottery scratch off cards, the RNG can be programmed to drop non-pay or add pay selections so as to keep a more even distribution of winners throughout the finite set of cards created. The goal is to maintain a more even distribution in the cards along with the payout percentage as required. Is this, or can this programming be done in Nevada? The law of averages would indicate no need for this, but is it not theoretically possible for a signed 97% slot machine to payout 95% one year and 99% the next year unless some control on the RNG was made?

Jonathan from Ft. Lauderdale

Thanks for the kind words. Scratch cards and pull tabs can indeed be printed in batches. These batches will have a specified number for each win, and the return of the overall batch will be exactly as the maker intended. In some jurisdictions, where only pull tabs are legal, the outcome can be displayed to the player on a video monitor, in the form of a slot or video poker machine. However, in Nevada, that is not how slots work. Each play is completely independent of the past. A machine programmed to average a 97% return, could indeed pay under 95% or over 99% over a year, especially if not heavily played.