• Appendices
• Slots Analysis
• Miscellaneous

• Slot Machine House Edge Calculator
• Real Slot Machines For Sale
• Slot Machine House Edge Definition
• Slot Machines For Home Entertainment

Slot machines have a house edge that varies based on the PAR sheet for the game. (That’s the logic behind the game which determines the probability of getting various combinations of symbols and the payouts for those combinations.) You can find slot machines with a house as high as 35% or as low as 5%, but you never know what the number is.

• If a slot has a house edge of 6%, which is extremely high, it could be because maybe the game manufacturer wants to offer bigger more profitable winnings instead of more frequent ones. But in this case, it's also important to consider the other factors such.
• On a slot machine, getting three cherries on a pay line might pay 100 for 1. But since you don’t know the probability of getting any of the symbols, it’s. The house edge (the amount the casino expects to win on every hand on average over time) is 0.46% on the 9/6 game. (It’s just 99.54% subtracted from 100%.).

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.

Before going further, let me make clear that this page addresses the way slot machines work in most parts of the United States and the world. However, some parts of this page do not apply everywhere. For example, I state that slot machines have a memory-less property, where the odds of every spin are the same. In some places, like the UK, some machines in bars, called 'fruit machines,' have a mechanism that guarantees a certain profit over the short run, which causes the game to go through loose and tight cycles. These games do not have the usual independence property of the major slot makers.

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

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. As a reminder, this page is based on slot machines commonly found in the United States. Some machines, like 'fruit machines' found in the United Kingdom work differently.

• 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

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 Cleopatra analysis of the popular IGT game.
• Deconstructing Lionfish analysis of the slot game found on many Game Maker machines.
• Deconstructing Megabucks.
• Deconstructing the Atkins Diet slot machine.
• Deconstructing Lucky Larry's Lobstermania.
• Deconstructing Hexbreaker.
• Deconstructing Blazing Sevens.
• 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

Everyone who has ever been in a casino has probably heard the term “house edge”. It is what serious, professional gamblers always pay close attention to, while recreational players tend to ignore it as some kind of pretentious Vegas lingo. In reality, the house edge indicates how profitable a game is and how much players should expect to win or lose while playing it. So, what is the house edge of slots and what does it mean to players?

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What Is the House Edge?

The house edge is one of the most important things in gambling literature and can also be referred to as a casino advantage or theoretical advantage. It exists in every game of chance – roulette, blackjack, lotteries, poker, and it is the mathematical advantage the house has over players. You have probably heard the expression – the house always wins. It is true and the evidence for this is the house edge.

This advantage is achieved by the rules of the games and the difference between the true odds and the so-called casino odds, i.e. the payouts. Typically, casinos pay slightly less than the real odds for a certain type of bet. A simple example is the straight bet in the French/European roulette – if we place a chip on 21 red, we face odds against winning of 36 to 1 since there is only one way to win against 36 ways to lose. However, the bet pays 35 to 1 rather than 36 to 1, which gives the casino house edge of 2.70%.

What Determines the House Edge in Slots

The same logic is applied to slots but it is impossible to calculate the exact percentage of the casino advantage since we do not have one crucial piece of information – the odds for each winning combination. Even though we can see the payouts for 3, 4, and 5-symbol combinations, we have no idea how likely each combo is to land on the reels. In other words, we cannot see how many winning and losing combinations there are in slot games.

Slot Machine House Edge Calculator

What casinos usually reveal about the games they offer is the theoretical advantage they have based on these odds. To better understand the house edge, let’s take the example from above. If we play roulette at a house edge of 2.70% (which is the percentage for all standard single-zero roulette games), we can expect to lose $2.70 on a $100 total wager on average.

How Volatility Affects the House Edge

The higher the percentage of the house edge, the more players are likely to lose over time – at least in theory. In reality, there is a level of randomness, of deviation from the perfect results, achieved by calculations. Even though the mathematical advantage indicates that we should lose $2.70 of every $100 bet, we will probably end up the game session with a very different outcome – we might have lost $50 or made a profit of $15 after wagering $100. Any other scenario is just as likely, however.

What the house edge indicates is the theoretical average of thousands and even millions of trials. The real-life games rely strongly on chance, however – an idea described by science as entropy. This level of chaos and unpredictability can be calculated and in gambling, it is referred to as variance or volatility. The variance shows how much real results can vary from the statistical average, while volatility measures the same thing only within a specific time. Overall, slots with high volatility give players the chance of winning big – at the same time, they could make you lose huge amounts of money within an hour or two.

The House Edge in Land-Based and Online Casinos

In terms of average returns and house edge, slots offer some of the worst odds in the casino. House edge is calculated by the percentage of return the machine offers to patrons, meaning that if the return is 85%, then the house edge is 15%. As we have explained above, the exact percentages are based on the payouts for each symbol combination, and the odds of the game, which remain undisclosed and a trade secret when it comes to slots. Standards in Vegas may vary significantly but the rates are, in most cases, advertised somewhere in the casino or even in front of it. The most common house edge you will find in Vegas varies from 5% to 17%, which is a lot.

Real Slot Machines For Sale

That being said, there are casinos claiming to offer slots with only a 1% house edge. However, such a high return is usually reserved for specific machines. If, by any chance, you happen to notice advertisements claiming such favorable odds, do not hesitate to enter and inquire the slots manager about the offer, how you can utilize it and for which machines it actually applies (because it usually applies to one or several machines around the house, but not all). This is some useful information you can get so you stand a better chance at winning.

Things are a bit different when it comes to online slots, though. The majority of online casinos clearly display the house edge – or the average return to player (RTP), on their websites and within the rules of the games. Although many of the slots offer house edge around 7%, the most popular titles usually promise much better returns and a house edge percentages between 2% and 5%.

Machines with the Highest Chance of Winning

It is nearly impossible to obtain inside information about the best machines where you stand the highest chance of winning. First and foremost, players should be warned that playing slots may a terrible idea considering the random nature of this game compared to skill-based games such as blackjack or poker. Moreover, there are no winning strategies and no way to secure profits over the long term when playing slots.

Nevertheless, slots offer great entertainment for millions of people and are currently, the most popular type of casino game. Despite their overall bad odds, they could bring some really attractive payouts to those who can spot the games with the highest returns and the lowest casino advantage. Some machines offer a smaller house edge and are more worth playing than others. It is difficult to identify them if the house edge (or the RTP) is not indicated on them, although there are several signs players may want to pay attention to.

The Size of the Casino

One of the things players should pay attention to is the size of the casino. Often, in big, elite casinos, the machines are rather stingy and carry a huge house edge. The reason is that most people who walk into those casinos have a larger bankroll and would not care that much if they lost a few hundred bucks on slots. Also, these casinos have an extended clientèle so they do not need to make attempts to provide everything in the house according to their clients’ needs.

Smaller casinos, on the other hand, cannot afford to lose patrons, so there, you will usually have a bigger chance of winning. You should not be under the illusion that you will always be winning in smaller casinos. You may enjoy some more personal treatment in these establishments but overall, if you have a high bankroll, you would definitely have a better time in one of the more elite casinos.

The Positioning of the Games

There are also myths surrounding the slots positioning on the gaming floor. Some people claim that certain machines on the sides tend to be looser, while others insist that those games are actually placed near the center in most cases so they can attract more attention. The truth is that unless you are slots manager in the particular venue, you cannot really say which machines are loose and where the good ones are placed – or if even there is a loose machine or not.

Even if there is something suggesting that at a certain point in time there was a slot in the center of the casino that was giving out 1% more than the other machines, casino managers tend to move them around so it is probably not going to be the same machine when you go to the casino, anyway. In case there is some truth to this idea, the differences in the house edge of the slots are so small that they are almost unnoticeable and you will only be able to detect them if you try really hard.

Choosing the Right Denomination

Choosing the proper slot game would not be enough in most cases. It is important to pick the proper coin denomination – or in other words, the bets you are making. Generally speaking, the more you bet, the smaller the house edge is, which is why most guides would advise you to bet the maximum coins. Instead of going for the mere quarters, go for the big bucks.

Casinos and game developers typically reduce the house edge for high-denomination games simply because most players tend to prefer the more affordable penny slots. Usually, machines where the minimum coin size is $1 return more than slots where you can play for as little as $0.05 per spin. This does not apply to all games, though.

However, even though it is usually true that the more you bet, the smaller house edge you face, it is also true that you are betting more. So, by definition, you would be losing more in the long term unless you are really lucky. The reason for this is very simple – even the slots with the best odds and payback percentages are still negative expectation games. So, even if you are on a long winning streak, eventually the house edge will pitch in – even if this is after a hundred spins. It is one thing to lose a quarter in a spin, but it is another thing altogether to lose something like $50. You need to keep these things in mind when you decide to play and always adjust the size of your bets in accordance with your bankroll.

Do Your Own Research

Slot Machine House Edge Definition

It is always a great idea to do research into the games we wish to play before starting to play them. We can compile vital information about each slot – how much it pays back on average, what volatility it has, what bonus features it has, etc. This is much easier to do when it comes to online slots – most casinos on the Internet allow their patrons to test the games in demo mode without betting real money. The rules of the games are also displayed in full, so you can instantly see the house edge, the betting limits, and the free spins or bonus features you can take advantage of.

Doing proper research into land-based casinos and the games they offer, on the other hand, could be a challenge. One of the best tactics is to simply ask the casino staff for information – they would be able to reveal any inside info or trade secrets but they would be willing to provide the RTP and house edge percentages of the slots. But asking the slots manager for information about the machines is often useless if you ask all the wrong questions.

A good example of a wrong and pointless question would be asking if a machine is hot or cold. To indulge you, the casino employee would probably pick a few slots at random, claiming that some of them are cold, while others hot. And do not be surprised if the staff enjoy watching you waste your money based on that information. They have not lied to you, however – this piece of information is simply irrelevant. The concept of hot and cold slots is not based on any sound logic or reason and it is just a myth.

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Slots Myths
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Slot Machines For Home Entertainment