Find Out Exactly How Slot Machines Function

The Concept of Random Outcomes with Slot Machines

Slot machines are among the most popular attractions at land-based casinos and online casinos alike. The appeal of slot machine games lies in the fact that anyone can win at any time. All it takes is a real money wager and a click, and a massive jackpot prize could be yours to enjoy. Behind the scenes, slot machines are anything but simple. In fact, these computerized technological innovations feature some of the most advanced technology in the gaming arena. The one aspect of slot machine games that the unassuming observer does not see from the outside is the concept of a random number generator. But what exactly is an RNG? Simply put, a random number generator is a highly complex software program that randomizes all outcomes to ensure that every spin generates a result that is independent of the previous spin in every way. Simulating randomness in a man-made creation may appear to be an insuperable challenge, but the world's leading software providers and gaming developers have perfected this.

There are several important points that players need to understand before embarking upon a slots session at a casino. The first of them is that your payout is always less than your odds of winning in a slot game, and the second point is that every time you spin the reels a random outcome will result. This is really no different to the outcome in a blackjack game, a roulette game, a video poker game, a craps shoot or a game of keno. The fact of the matter is that online slots games, like all other casino games are designed to give the casino an edge in the long-term, but in the short-term incredible things can happen for players. If you look at things like RTP (return to player), you will always notice that the percentage is less than 100% on the vast majority of casino games. Why is this the case? Because, any number greater than 100% would guarantee that casinos would lose money and would shutter operations and cease to exist. Therefore, your objective as a slot machine player is to seek games with RTP figures that are as close to 100% as possible.


Pattern and Trend Analysis

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Fortunately, the leading online casinos offer slots games with payout percentages in the region of 92% – 96% on average. This is substantially higher than the RTP figures for land-based casinos which have to factor in many additional cost elements into the equation. Owing to high fixed costs of operations, high variable costs, and other costs associated with running a land-based facility, the RTP with land-based slot machine games is substantially less than it is at online casinos. Even so, the random number generators are always in effect regardless of where you play slot machine games. Many players tend to believe in all manner of myths, superstitions, old wives tales and the like. The fact of the matter is that there is no slot machine game that runs hot or cold – everything is randomly generated. Many folks believe that this if a slot machine game has not paid out recently, it is due to pay out ASAP. This is simply nonsensical: there is no logic behind the assertion that any machine is due for a payout since everything is randomly determined.

The concept of randomness is something that casino players find very difficult to understand, since the appeal of a casino is deeply rooted in a feeling of good fortune that players have while they are playing. In other words we believe that today is our lucky day, or that perhaps tomorrow will be our lucky day. There is nothing wrong with this thinking, except for the fact that slot machines are governed by algorithms that ensure fairness, credibility and randomness of all outcomes. If you believe that casinos are able to flout the RNG component of slot machine games, think again. Every online casino that operates within the strict regulatory code of gambling authorities has no option but to comply with independent testing standards (TST), random number generator fairness and the rules of authorities like the Malta Gaming Authority (MGA), Gibraltar, the UK Gambling Commission, the New Jersey Department of Gaming Enforcement and other regulatory authorities around the world.

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If we consider the Nevada Gaming Regulation as a case in point, it is clear that the random component of casino gaming is an intractable element of all operations. The randomness of a slot machine game ensures that the previous outcome has absolutely zero impact on the future outcome, and the amount of coins that you deposit has absolutely no correlation with the symbols that line up on the spinning reels. There is however a correlation between the number of coins that you play and the size of the jackpot that you receive – but as for the actual symbols that result from the random number generator, there is no connection. And just for the record, there is no rule or truth to the assertion that slot machines have to make up a certain payout quota within a certain period of time. In other words if the machine hasn't paid out X amount of dollars by the end of the month, it will not suddenly rush to make payouts just before the month is about to close out to meet that quota. This is all rooted in the concept of randomness of outcomes.

Understanding slot machine gaming

In order to understand how a slot machine would be beneficial for the purposes of profitability in a casino, let us consider a simple coin toss. With every flip of a coin, you have a 50% chance of being correct. In the long-term, over thousands upon thousands of coin tosses you will likely break even. This is why 50-50 games like that are not offered in casinos. The way casinos make money is by offering a lower payout percentage than the actual true odds of the outcome occurring. In other words if you bet on tails and you lost, you would lose your full wager, however if you bet on heads and you won, the casino would give you say 80% to 90% return on winning bets. The remaining percentage stays with the house, and this is how they make money in the long term. This is known as the casino edge, and it is often expressed as a percentage. In the above examples, it was mentioned that slot machine RTP figures range from 92% to 96%. This is the casino edge and this is how they ensure their profitability over the long-term. In other words, for every $1 that you wager, you will win back $0.92 or $0.96 in the long-term – the rest will be won by the casino. And so it is with slot machine games too. Before one dismisses casinos as moneymaking entities, one has to accept that they run a tremendous risk over the short-term and the RTP figure is simply a safeguard for the risks that online casinos and land-based casinos take on when offering high-paying slot machine jackpots to players.

You may be wondering how a random number generator actually functions in a practical way. Fortunately, it's a lot less complicated than the tech gurus would like us to believe. Each slot machine has a certain number of spinning reels and a certain number of symbols. There are also a certain number of paylines, sometimes they are fixed and sometimes they are not. For each reel, the random number generator will select a random number which is associated with the symbol. The number of symbols in each slot game is vast, and can be seen in things like the paytable of the game that you are playing. By the time you have deposited coins in the slot at a land-based casino, or virtually done so at an online casino, the random number generator has already determined the outcomes. What you see playing out in front of you is merely for entertainment purposes only. That's why many casinos offer quick-result functionality where you can simply click the spin button and the results are generated immediately. You don't need to go through the rigmarole of watching the reels spin and individual reels coming to a stop one after the other. It should be pointed out that standard non-progressive slot games will typically feature between 35 and 50 stopping points per spinning reel. If we move onto electromechanical slot machine games with invisible reels, you could have as many as 256 stops. The actual mathematics of slot machine games vis-a-vis random number generators gets highly complicated, so consider the following table as an indication of symbols, selected numbers and possible outcomes.



Jackpot Amount



Double Diamond

2500 coins

1 in 46,656

Par sheets obtained by Canadian researchers (PDF)

Blazing 7's

5000 coins

1 in 93, 312

Bally's par sheet (PDF)

Phantom of the Opera

5000 coins

1 in 114,131
1 in 155,345

Par sheets obtained by Canadian researchers (PDF)

Red White & Blue

2400 coins

1 in 262,144

Wizard of Odds

Double Strike

5000 coins

1 in 500,000

Wizard of Odds (estimate)

Money Storm

10,000 to 50,000

1 in 2,188,411

Par sheets obtained by Canadian researchers (PDF)

Lucky Larry's Lobstermania

10,000 to 50,000

1 in 8,107,500


$8 to $33 million

1 in 49,836,032

John Robison in Casino City Times


Note that there are often different versions of machines with the same name, so the numbers above might not apply to every flavor of the named machine. What you should take from this is that as the jackpot goes up, so does the difficulty in actually hitting it.

By the way, the odds of getting combinations of symbols on successive reels diminish with each additional reel that you're playing in a slot machine game. In other words if you're playing a 3 reel slot machine game, you are more likely to win by lining up the requisite number of symbols than you are if you're playing a 5 reel video slot machine game. Many players get overly excited when they hit the first Jackpot symbol on the first reel, hoping for another Jackpot symbol on the second, third, fourth or fifth reel. However the likelihood of doing so diminishes with each additional reel that is being played. In other words, spinning reels in slot machine games are weighted, and for the most part there is no logical assumption that all the reels in any game that you play have an equal weighting.

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RNGs are highly complex mechanisms that work even when you're not at your computer or at the slot machine game in person. That's because they are continually selecting random combinations of numbers from thousands of possible combinations. So in between your spins, different combinations of outcomes are being calculated by the random number generator in the game that you're playing. The more you delay, the more the RNG will be calculating. Fortunately, every single outcome is random and it is not designed to favour any player over any other player. It's also one of the most reassuring aspects of slot machine gaming since you know for a fact that nobody is sitting there trying to manipulate the system against you. It is as random as random can be and that's why you always stand a chance of winning, even on your very first spin!

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Licensing and regulation

Genesis Global Limited is incorporated under the laws of Malta (C65325) at registered address 28, GB Buildings, Level 3, Watar Street, Ta’ Xbiex, XBX 1301, Malta. Genesis Global Limited is licensed and regulated by the Malta Gaming Authority with licence number MGA/B2C/314/2015 issued on the 5th August 2016 and also by the British Gambling Commission with account 45235. Gambling can be harmful; our Responsible Gaming page helps you to stay in control.




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