Casino Slot Machines How They Work

They make slot machines and traditional casino games more appealing. Here are some of the skill-based slot games that have been making their rounds in casinos: Danger Arena / Pharaoh’s Secret Temple. All casino games, including slots, offered by licensed online casinos, also work on the same principle as class 3 slot machines. When it comes to class II slot machines, these can be mostly found on Indian gaming reservations and illegal gambling establishments as well as unlicensed online casinos, where state regulations don't apply. Slot machines use a random number generator. Early slot machines were mechanical (think coin slots), but they still used a random number generator, in the same sense that a roulette wheel, a deck of cards, or a pair of dice are also random number generators. Slot Machines - How to Win and How They Work with American Casino Guide Author Steve Bourie Slot machine video from casino expert Steve Bourie that teaches you the insider secrets to winning at slot machines and how a slot machine really works.

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The first time I saw people use member cards for slot games, I didn’t know what they were. I asked the man sitting next to me and he explained a few details about the rewards club. But he wasn’t using a card himself.

When I asked him why, he said he once had a card but stopped winning when he played with the card. He thought the casino was monitoring his playing and adjusting the slot game results.

This rumor has circulated both online and offline for many years. It’s normal for people to hear something repeatedly and wonder if there is truth to it. But I’ve never found any proof that casinos can change the way slot games play by flipping a switch.

What makes it difficult to combat this idea and other rumors about slot machines is the many different markets where you find them. Slot machine games are regulated by each country. Complying with different regulations may mean that a slot maker must change how its games work.

The clearest example I can give is how slot games are decided in the United States. Class II slot games decide the outcome on the basis of one random number then configure the display to match that result. Class III games use several random numbers to control the reels.

How Modern Slot Machine Games Work

There aren’t many physical slot games left. They’re all electronic now, and the electronic machines use random number generator chips to decide results.

But there is more involved than just generating a random number. The “slots” in the slot games are spaces on reels. The computers now simulate these reels.

When you push “Spin” and the reels go round and round, it’s just a computer showing you pictures based on the numbers it generated. It’s a lot like an astrophysicist running a simulation of the stars moving around the galaxy.

Former and current slot machine manufacturing employees answer questions about game design on several websites including Quora. This answer was posted in September 2014, and it explains how the simulated reels are managed by software.

The programs to simulate the reels and assign the random numbers are etched into ROMs, Read-Only Memory chips. These ROMs must be physically changed by a technician to change how the game payout percentages work.

Legitimate Online Casino Operators Lease Games From Service Providers

There are over 2,000 online casinos. It’s impossible to be sure about how they all manage their slot games. But what is known about the most popular casinos is that they don’t run their slot games from their own servers.

Instead the online casinos lease game services from secure data centers. These gaming platforms are run by companies like Blue Ocean and EveryMatrix. Some of the game design companies also run their own servers, leasing resources to online casinos.

Although it would be simple for online gaming companies to switch things up, they would risk losing independent certifications if they allowed the games to be rigged.

There’s no need for casinos to adjust the percentages. They can order the percentage breakouts for house edge and return to player that they want to offer. This way, they maintain competitiveness and support long-term profitability.

Many Games Publish the Theoretical Return to Player

Some slot games include the theoretical return to player in their help screens.

These reported percentages must change when the games are reprogrammed or the casino risks being charged with fraud.

If the players see that RTP has been adjusted downward, they can play elsewhere. If players only suspect that the RTP has been adjusted without proper notification, they might still leave.

Casinos need players. The best strategy to grow their customer base is to keep game rewards high enough to make the risk worthwhile.

Some Governments Regulate Return to Player Percentages

Licensed gaming casinos must comply with local laws governing their businesses. Some countries provide more regulation than others.

In the United States, commercial land-based casinos are regulated by their states. However, Native American casinos are mostly regulated by the tribal governments that own them. Each jurisdiction has the authority to set minimal RTP percentages to ensure the casinos don’t make too much money.

The 1988 Indian Gaming Regulatory Act creates the legal framework used by tribes to protect their traditional gaming activities from state regulatory laws. The act also defines the three classes of gaming and how they are to be regulated.

Class II games are regulated by the tribes but only in states that allow any kind of gaming. Only Class III games are subject solely to state regulation.

True slot machine games are Class III games. Native American casinos offer Class II bingo games that are made to look like slot games. The game cabinets must display the casino bingo games that are used to determine wins.

Class II slot machines may have reels and bonus games but they’re not really slot machine games as defined by federal law.

How Do You Determine the Odds That a Slot Game Pays?

Casinos may or may not be required to declare the return to player for their slot games. Some casinos place a plate or sticker on their slot games with a notice. Other casinos leave it to the game help screens (thus, the manufacturers) to inform players.

The games’ odds may be reported as a theoretical RTP percentage, but they could also be reported as a ratio, similar to the way lottery games declare chances of winning a prize. Either way, these games don’t have to tell you how often to expect to win a prize of any amount.

Some players merely judge the looseness of slot games by how much money they win or how often they win as they play the games.

Casino Slot Machines How They Work

Some players judge the looseness of slot games by how popular they appear to be. This observational strategy assumes that the crowd knows more than the individual.

Local patrons who play regularly often settle upon favored games they believe are lucky. In other words, you have no way of knowing for sure how loose a slot game is.

One of my friends tells me he only plays slot games with low jackpots. His reasoning is that players need to lose less money for someone to win $10,000 than for someone to win $20,000.

Slot Machines May Have Programmed Payout Limits

In another post on Quora from 2016, someone claimed to have industry experience in the Caribbean.

In his post, he said that a machine won’t pay more than it has accumulated after the first month of operation. That first month establishes the limit based on the profit the machine made.

The system is designed to be random within a range of percentages. The software decides when and how much to pay but won’t go over the monthly limit.

It should be obvious that this limit could be reset.

The Games Are Designed to Be as Random as Possible


People who design and repair slot machine games express much trust in the random number generator chips these games use. The RNGs, as they are called, use the latest available algorithms at the time they are manufactured.

Math has not yet progressed to the point where truly random numbers can be generated. Mechanical devices require input from an outside source to be truly random.

The way slot game designers handle this limitation is they design the chips to generate thousands of random numbers every second. The random numbers each take a turn at being available for use by the game.

When a human player presses the “Spin” button, or sets a game on “Autoplay,” their action is the final ingredient in the algorithm. That is what makes these games random.

Because of the percentage payouts and internal limits they use, slot machine games don’t have to be reprogrammed to improve casino profits. Everything is designed to run with as little intervention as possible.

And that is better for the casino because the more they can intervene in a game’s function, the more likely they’ll face regulation over that intervention.

Casino game techs often say that replacing chips in slot machines must follow a special procedure (in the United States). They are closely monitored and every part must be accounted for. So, it’s less expensive for casinos if they don’t tweak the games.

Conclusion

An honest casino doesn’t need to control who wins at a slot game. They already control who can play a slot game. They can ask anyone to leave for any reason.

Naturally, casinos don’t do that. Instead. they purchase gaming systems that are designed to create an entertaining experience for patrons while legally retaining a profitable percentage of wagers.

Casino Slot Machines How They Work

No matter how much one’s frustration tempts a player into wondering about Big Brother Casino tweaking the game, it’s more profitable for the casino to let nature take its course.

On This Page

Introduction

When it comes to gambling, the easier a game is to understand the worse the odds usually are. This is certainly the case with slot machines. Playing them is as easy as pressing a button. However, between the high house edge and fast rate of play, there is no quicker way to lose your money in a casino.

How They Work

Whether you're playing a 3-reel single-line game or a 5-reel 25-line game, the outcome of every bet is ultimately determined by random numbers. The game will choose one random number for each reel, map that number onto a position on the reel, stop the reel in the appointed place, and score whatever the outcome is. In other words, the outcome is predestined the moment you press the button; the rest is just for show. There are no hot and cold cycles; your odds are the same for every spin on a given machine.

Slot machines are just about the only game in the casino where the odds are not quantifiable. In other words, the player doesn't know how the game was designed, so it is difficult to look at an actual game to use as an example. So, to help explain how they work, I created the Atkins Diet slot machine (link). It is a simple, five-reel game with a free spin bonus round, much like IGT's Cleopatra game.

For information on how it works and all the odds, please visit my Atkins Diet par sheet.

For a more complicated example, featuring sticky wilds in the bonus, please try my Vamos a Las Vegas slot machine.

For information on how it works and all the odds, please visit my Vamos a Las Vegas par sheet (PDF).

Odds

The following table shows the casino win for Clark County Nevada (where Las Vegas is) for all slots for calendar year 2012. They define 'slot' as any electronic game, including video poker and video keno. I've found video keno to be about equally as tight as reeled slots, but video poker has a much higher return. So, the return for reeled slots should be higher than these figures.

Clark County Slot Win 2012

DenominationCasino Win (pct)
$0.0110.77%
$0.055.96%
$0.255.74%
$1.005.64%
$5.005.51%
$25.003.97%
$100.004.73%
Megabucks12.89%
Multi-denomination5.32%
Total6.58%
Machines

Can Casinos Adjust Slot Machines

Source: Nevada Gaming Control Board, Gaming Revenue Report for December 2012 (PDF, see page 6).

Most players play penny video slots. Based on past research, I find the house edge on those to usually be set from 6% to 15%. In general, the nicer the casino, the tighter the slots.

Advice

While there is no skill to playing slots, there is some skill in selecting which machine to play and ways you can maximize your return. What follows is my advice, if you must play slots at all.

  • Always use a player card. Slots may be a lousy bet, but the casinos treat slot players very well. A $1 slot player will probably get comped better than a $100 blackjack player. Of course, don't play for the reason of getting comps. You'll give them a lot more than they'll give you.
  • The simpler the game, the better the odds. The fancy games with big signs and video screens tend to not pay as well as the simple games. However, slot players always tell me the fancy games are more fun.
  • The higher the denomination, the better the odds. For that reason, it is better to play one coin per line on a 5-cent game than five coins per line on a 1-cent game.
  • Don't forget to cash out and take your ticket when you leave. It is easy to forget after hitting a jackpot.
  • Try to play slowly and as little as possible to get your fix.
  • In some games there is a skill feature, like Top Dollar. In such games, advice is usually offered, which you should take.

Myths and Facts

Just about everything that players believe about slots is untrue. Here are the most common myths and facts.

  • Myth: Slot machines are programmed to go through a cycle of payoffs. Although the cycle can span thousands of spins, once it reaches the end the outcomes will repeat themselves in exactly the same order as the last cycle.

    Fact: This is not true at all. Every spin is random and independent of all past spins.

  • Myth: Slot machines are programmed to pay off a particular percentage of money bet. Thus, after a jackpot is hit the machine will tighten up to get back in balance. On the other hand, when a jackpot has not been hit for a long time it is overdue and more likely to hit.

    Fact: As just mentioned, each spin is independent of all past spins. That means that for a given machine game, the odds are always the same. It makes no difference when the last jackpot was hit or how much the game paid out in the last hour, day, week, or any period of time.

  • Myth: Machines pay more if a player card is not used.

    Fact: The mechanism that determines the outcome of each play does not consider whether a card is used or not. The odds are the same with or without one.

  • Myth: Using a player card enables the casino to report my winnings to the IRS.

    Fact: That makes no difference. If you win $1,200 or more they will report it either way. If you have a net losing year, which you probably will, at least the casino will have evidence of it. Such annual win/loss statements may be used as evidence to declare offsetting loses to jackpot wins.

  • Myth: The slot department can tighten my game with the press of a button remotely. Thus, you better be nice to the staff and tip them well, or they will use a remote control to have the machine take you down in a hurry.

    Fact: There is now some truth to the myth that the odds of a machine can be changed remotely. Such 'server-based slots' are still experimental and in a minority. Even with server-based slots, there are regulations in place to protect the player from the perceived abuses that could accompany them. For example, in Nevada a machine can not be altered remotely unless it has been idle for at least four minutes. Even then, the game will display a notice that it is being serviced during such changes. (source) Meanwhile, for the vast majority of slots, somebody would physically need to open the machine and change a computer chip, known as an EPROM chip, to make any changes.

  • Myth: The machines by the doors and heavy traffic flow areas tend to be loose while those hidden in quiet corners tend to be tight.

    Fact: I've studied the relationship between slot placement and return and found no correlation. Every slot director I've asked about this laughs it off as just another player myth.

  • Myth: Slots tend to be looser during slow hours on slow days of the week. However, when the casino is busy they tighten them up.

    Fact: Nobody would take the trouble to do this, even if he could. The fact of the matter is the casinos are trying to find a good balance between winning some money while letting the player leave happy. That is best achieved by slots loose enough to give the player a sufficiently long 'time on device,' as they call it in the industry, with a reasonable chance of winning so he will return to the same casino next time. If the slots are too tight, the players will sense it and be unlikely to return.

    The kind of place you're likely to find tight slots are those with a captive audience, like the Las Vegas airport. So, if the slot manager feels that 92% is the right return for a penny game, for example, he is likely to set every penny game all that way, and keep them that way for years.

Play

Atkins Diet


Analysis

Vamos a Las Vegas


Analysis (PDF).

Australian Reels — One Line


Analysis (PDF)

Australian Reels — Five Line


Analysis

21 Bell


Analysis

Fruit Machine


Analysis

Reviews

  • Dazzle Me (NetEnt)
  • Mr. Vegas (Betsoft)
  • Sparks (NetEnt)

Internal Links

  • Appendix 1 shows the details and analysis of almost 4000 actual spins on a Reno slot machine.
  • Appendix 2 shows an example of the virtual reels behind a hypothetical slot machine and how the average return is calculated.
  • Appendix 3A: 2003 Las Vegas slot machine rankings.
  • Appendix 3B: 2002 Jean/Primm slot machine rankings.
  • Appendix 3C: 2002 Tunica slot machine rankings.
  • Appendix 3D: 2002 Henderson/Lake Mead slot machine rankings.
  • Appendix 3E: 2002 Quarter and dollar returns for Las Vegas slots
  • Appendix 4 shows how the return is calculated for my Wizard's Fruit Slot Machine.
  • Appendix 5 analysis of the 21 Bell Slot Machine.
  • Appendix 6 Analysis of Red, White, & Blue Slot Machine.
  • Lock and Roll analysis of the skill-based slot machine found in North Carolina.
  • Deconstructing Jackpot Party analysis of the video slot machine.
  • Deconstructing Lion's Share analysis of the classic MGM progressive game.
  • Deconstructing Megabucks.
  • Deconstructing the Atkins Diet slot machine.
  • Analysis of Lucky Larry's Lobstermania.
  • Deconstructing Hexbreaker.
  • Deconstructing Blazing Sevens.
  • Deconstructing Lionfish.
  • Deconstructing Hot Roll.
  • Mystery progressives on Ainsworth slots.
  • Mystery progressives on WMS slots.
  • Baltimore Sun article, in which I am quoted.
  • 100% Rebate on Slot Losses Promotions: When to quit playing when all losses are refunded.

External Links

  • For a simplified explanation of slots, please see my companion site Wizard of Vegas
  • German translation of this page is available at richtigspielen.com
  • Another decent overview of how slots work and some practical advice for playing them is How Slot Machines Work at VegasClick.com.
  • PAR Sheets, probabilities, and slot machine play: Implications for problem and non-problem gambling by Kevin A. Harrigan and Mike Dixon, University of Waterloo, Waterloo, Ontario, Canada. This is an outstanding academic paper that details how some popular slot machines were designed.
  • PAR Sheets, probabilities, and slot machine play: Implications for problem and non-problem gambling - Academic paper based on the par sheets for some modern slot machines

Best Slot Machines At Casinos


Can Casinos Control Slot Machines

Written by:Michael Shackleford