How Slots Work

Ever wanted to know how you can have the best chance at slot machines? Well, in this guide, we dispel some myths and give you the facts on how you can trigger slot wins as well as how to improve your potential. So, if you’re ready to spin like a pro, here’s our guide to slot secrets, payouts, jackpots and more.

How Slots Work

You can’t answer the question of how to play slot machines without knowing how they work. Now, we’re not going to delve into the technology that powers the latest and greatest online slots. However, we do need to talk about the basics of playing. Once you understand what you’re up against, you’ll have a better chance of making the right moves that could lead to a win. You can find out more about how to play slots in our dedicated article.

What are slot machines?

Slot machines are games that involve two main elements: reels and symbols. In the old days, a lever would trigger a set of mechanical reels. Today, the most popular games are virtual affairs offered by online betting and gaming sites like Paddy Power.

How mechanical slot machines work

In the days of mechanical slots, players would pull a lever that put a set of reels in motion. Each of these reels would spin independently and come to a stop after a second or two. On each reel, there would be a selection of symbols. If you lined up a certain number of symbols, you’d win a prize.

How online slot machines work

In today’s world, levers and mechanical reels have been swapped for animations. Thanks to random number generator (RNG) software, online slots can produce fair results just like their offline counterparts. The only difference is that the spins are animated. Other than that, matching symbols will trigger a payout.

Real money slot games

Without the ability to play for real money, there wouldn’t be any casino slot winners. Yes, in today’s world, there are ways to play demo games for free. However, if you use these slots, you can’t win real cash. Therefore, if you want to bank something tangible, you have to play for money.

As a general rule, the size of your prize will hinge on two factors: the amount you stake and the combination you hit. Matching five symbols is always worth more than matching four or three. However, every online slot has its own payout dynamics. Beyond that, prizes are often multiples of your stake. For example, you could match three cherries and the slot will reward you with a 3x payout. Therefore, if your bet size is one coin, you’d win three coins.

Slot game bonus features

To make modern slots more entertaining, developers include a variety of bonus features. These will vary from game to game but they’ll often fall within the following categories:

  1. Free Spins: As their name suggests, free spin bonuses give you a set number of gratis turns. Free spins can often be accompanied by something known as multipliers. These added extras will basically multiply whatever prize you win by a certain number.
  2. Mystery Pick’em Bonuses: This slot bonus allows you to unlock mystery prizes. This could involve opening a locked chest, rolling dice, moving along a pathway, or shooting at random targets.
  3. Gamble Bonus: The final type of slots bonus you’ll find online are gamble games. Whether it’s higher/lower, red/black or some other prediction, you can increase the value of your prize by making a correct pick.

Slot scatter symbol meaning

To unlock the aforementioned bonuses, you’ll need to match a certain number of special symbols. These are often known as scatters and they operate independently from a game’s main symbols. As you’d expect, the look of a scatter will be attached to the theme of the slot. However, if you want to win at slots, it pays to match scatters as they trigger bonuses that can often offer higher returns than fixed wins.

Slots paylines meaning

In addition to reels, paylines help you make winning combinations. In simple terms, a payline runs from left to right across the reels. To make a winning combination, you need to match symbols across a payline. For example, there may be a single payline running through the middle of the reels. To unlock a prize, you’d need to match symbols along this line.

To give you more payout potential, modern slots feature multiple paylines. These can crisscross the reels, which means you can make winning combinations in a variety of directions. Moreover, with multiple paylines in play, you can make more than one winning combination per spin. In fact, when you’re thinking about how to try to beat a slot machine, you should consider the number of paylines. In general, the more paylines there are, the more likely you are to hit a winning combo.

What Are the Chances Of Hitting a Real Money Win at Online Slots?

The chances of hitting a slots win will vary from game to game. However, you can size up certain variables to better understand your chances of making a return on your investment.

Are slot machines programmed or random?

Every online slot produces random results. However, there’s a certain amount of programming that goes into it. Put simply, every spin produces a random result within a certain framework. This framework is known as the return to player (RTP). RTP is the number that determines how often you’ll win, in theory, over a significant number of spins. In this context, significant can mean 10,000+ or 100,000+ spins.

Now, it’s important to understand that this is your theoretical return rate. In the short term, the results may not reflect the projected rate. However, over time, your results should move somewhere close to the score calculated.

Once a developer has set the RTP of a slots machine, results will be randomised within that framework. So, in simple terms, all slots are random. However, they also have a set return rate, which means there’s some degree of certainty (i.e. your theoretical return rate) among the uncertainty.

What is a slot RNG (random number generator)?

RNGs are computer programs that use complex algorithms to produce random results. To get random results, all online slots are based on something known as a random number generator (RNG).  Put simply, each time you spin, some mathematical wizardry happens behind the scenes. This wizardry translates into a long string of random numbers which, in turn, generate a sequence of symbols on the screen.

How to play slot machines using an RNG

Finding winning slots isn’t easy. In fact, because of RNG technology, it’s impossible to predict which symbols are going to spin into view or when a jackpot will strike. However, that doesn’t mean you can’t win at slots with RNGs. Even though you can’t predict outcomes, you can choose the best playing conditions. In practice, this means assessing a game’s RTP score – i.e. the higher the percentage, the better the potential payout rate should be. This isn’t the only factor in the equation. However, it’s a great starting point for anyone wanting to win at slots.

Do random results mean equal results?

No. As we’ve said, slots are random within specific parameters. This means each result is random but there is a certain degree of control over the results. To put it another way, there is a predetermined overall return rate and each random spin has to fit this condition. Therefore, you may go through patches where you win every other spin and times when it takes dozens of spins to bank a prize. This is part of the excitement of the game.

How to calculate the probability of winning at slot machines

The easy way to calculate the probability of winning at casino slot machines is to look at the RTP score. These scores are expressed as percentages and will give you an idea of how much of a return you can expect, in theory, over a large sample size.

For example, the Blue Wizard slot game here at Paddy Power Games has an RTP of 96.51%. This basically means that you should expect to get 96 units back for every 100 you stake. Of course, this isn’t set in stone, and you could potentially win well. However, that’s the baseline return rate you should expect over a large number of spins.

What is slots volatility?

Slots volatility is the term used to describe the amount of risk in a game. In simple terms, it describes how often you may go without winning/losing. Slot volatility is measured in numbers and can be low, medium or high. In general, low volatility slots pay out smaller wins more often while prizes in high volatility games typically take longer to hit but are larger when they do.

How does probability impact volatility?

In reality, probability and volatility don’t always have a bearing on each other. For example, a slot may have a high RTP and high volatility score. In practice, this means there’s a strong chance you will go through long periods without winning. However, when you do win, the prizes could be significant.

The RTP should be seen as a goal and the volatility is the path you take to get to it. Sometimes the path will be littered with smaller prizes. Sometimes there will be long gaps before a big prize drops. Either way, you should, in theory, always end up at the same destination.

Winning at Different Types of Slot Games

Are all slots created equal? In reality, the answer is no. Let us explain...

Do Some Slot Machines Pay Out More Often than Others?

Yes. A slot’s payout potential is determined by its RTP and volatility score. The lower the volatility, the more often you’re likely to receive a prize. However, this prize is likely to be slightly smaller, on average, than prizes that drop when a high volatility game pays out. 

Whenever you’re trying to win at slots, you should only ever spend what you can afford. To give you an idea of how to play slot machines with different betting options, here’s a quick overview:

Chances of winning at higher denomination slots

Some slots allow you to improve your chances of winning by betting more. This could be through an internal dynamic that gives high rollers access to larger payouts.

Chances of winning at penny slots

The chances of winning at penny slots should be just as good as at any other game. The beauty of these spinners is that the return rates are fantastic when you do win because you can win hundreds and sometimes thousands by betting a few pence.

Chances of winning at progressive jackpot slots

In general, progressive jackpot slots have lower RTPs than video slots or three-reel classics. The reason for this is that the payouts can be a lot bigger when they do drop.

For example, the average fixed jackpot for a video slot might be 10,000 coins. With a progressive jackpot game, the top prize is always increasing until someone wins. Therefore, you could turn a few coins into a payout worth millions. For that reason, the RTP is lower on these slots but the potential wins are much better.

Are high limit slots better?

Not necessarily. When you’re thinking about how to beat slot machines on casino sites, the main thing you need to consider is your bankroll. Yes, betting more could lead to big wins on slot machines. However, if you spend all of your money and can’t play, the potential payouts count for nothing. Therefore, you should always stick to limits you can afford.  

Slot Machines Return to Player and Payback

In any game with random outcomes, probability determines how likely you are to win or lose. For example, when you flip a coin, it can either land on heads or tails. Therefore, the probability of either is 50/50.

When you play slots, it’s a similar story. However, with dozens of reels, symbols and paylines, the maths is a lot more complex. Fortunately, you can get an idea of a game’s probability by noting its RTP score. This score is expressed as a percentage and will tell you how probable wins are over a long period of time.

Using probability and RTP to calculate volatility

To get an understanding of volatility of slot games, you need to consider probability and RTP. Basically, by knowing how likely a slot is to pay and what the overall potential is, you can get an insight into how volatile it may be. However, what’s also important to note is that volatility doesn’t always reflect RTP scores. As we’ve said, you can find a low-RTP and high-volatility slot game, and vice versa.

What is RTP (return to player)?

Expressed as a percentage, RTP is the amount you can expect to get back per 100 units wagered over a significant number of trials. Again, this score is a mathematical calculation. This means it’s a theoretical total and not a rule set in stone. Basically, an RTP score tells you how much to expect, not exactly how much you’ll get.

RTP vs. variance

In mathematics, variance is defined as the average of the squared difference of the mean. In other words, it measures how results fluctuate around an expected result. So, if we know a slot’s RTP is 98%, we might see return rates in the short-term range from 90% to 99%. These fluctuations are natural and part of the reason slots are entertaining.

If you plot each result on a graph over time, you’ll find that they eventually converge on the projected RTP. These short-term movements are the variance inherent in a game. Another way to describe variance in the slots world is volatility. As a player, you should expect variance to play a role in every game. That’s what makes things exciting. Moreover, it’s what makes winning at slots so unexpected and exciting.

How does RTP impact the chances of winning?

If you’re looking at your betting career as a whole, RTP is hugely important. As we’ve said, this is the amount you can expect to get back for every 100 units you wager over time. Therefore, the higher the RTP of a game you choose, the better your chances of winning at slots will be.

However, it’s also important to note that anything can happen in the short term. Even if a slot has a low RTP score, you could win multiple times and, moreover, it is entirely possible to bank large sums of money. So, while you should take into account a slot’s RTP, you shouldn’t get too fixated on it.  

The impact of house edge in winning at slot games

In the slots world, house edge is basically another way of saying RTP. If a slot has an RTP of 97%, the house edge is 3%. Therefore, it’s in your best interest to play slots with the highest RTP and, therefore, the lowest house edge.

Possible outcomes in slots

If we’re being blunt, there are only two possible outcomes in slot games: you win or you lose. However, within this black and white system, there is some grey. For example, there are big wins on slots and there are small wins. Moreover, there are free spins and bonus rounds, which can also be considered wins.

Then, of course, there are big losses and small losses. Moreover, you could unlock a bonus round but not win anything. This could be considered a loss. So, while it’s true to say that playing slots is all about wins and losses, there’s a lot that goes into it.

Slot machine probability

The probability of winning when you play slots is fairly low compared to something like a coin flip. When you toss a coin, the probability of winning vs. losing is 50/50. In a slot game with multiple symbols and possibilities, the chances of striking the right combination are lower.

However, this is why decisions matter. By choosing the right games i.e. those with the most reels, paylines, bonuses and best RTP, you have the opportunity to move things more in your favour. Indeed, with some slots having RTPs as high as 98%, you can pick high probability games and have a better overall chance of picking up some prizes. 

How many reel combinations are there in slot games?

When you’re assessing slot odds, you should always take into account the number of reels and paylines in play. As a general guide, modern online slots feature three, five and, sometimes, six reels. There are even games with more than six reels. However, the most common setups feature three or five.

Within these games, you’ll also find multiple paylines. The more paylines a game has, the more ways you have to make winning combinations. Therefore, as a quick rule of thumb on how to beat a slot machine, it’s a good idea to play those games with the most reels and paylines. Of course, you also need to consider a game’s RTP and volatility. 

Do similar slot games have the same payback?

No. In fact, the reason online slots are so popular is that every game is different. Even if two slots have similar themes and in-game dynamics, their RTP and volatility scores can be different. Yes, there are some industry standards with regards to payout potential, etc. For example, RTP for video slots typically ranges from 94% to 98%. However, it’s rare that two slots have exactly the same payouts and payout potential.

Slot Machine Odds

All this talk of slot odds is great, but what does it all mean in practice? Without knowing how and why odds exist, you'll never be able to develop a winning slots strategy.

The Odds of Winning on a Slot Machine

The odds of winning on a slot machine will be determined by its RTP. Every game is different, which means it’s your job to find the best odds slot machines. Now, if you’ve followed our advice up until this point, you’ll know that anything can happen on a single spin. Even if a slot’s payout odds are low, you could still hit a mega jackpot. However, when you play slot machines with the best odds, you’re basically giving yourself a better chance to win in the long run. That should be your goal whenever you play – in addition, of course, to choosing online slots that you enjoy playing.

How are slots odds determined?

The odds of winning on a slot machine are determined by its RTP, volatility score and prize board. Although it’s not easy to calculate exactly how likely or unlikely you are to win on any given spin, you can get a general sense of whether or not the odds are better in one game over another. For example, a slot with an RTP of 98%, volatility of 20 and a jackpot of 100,000 coins should have better overall odds than one with a 90% RTP, 50 volatility and a 10,000-coin jackpot.

What are weighted slots?

Weighted slots are games where a certain symbol/symbols are more likely to hit than others. In general, low-value symbols will be weighted to appear more frequently than high-value ones. This means you’re more likely to hit smaller wins. However, the counter is that, when high-value symbols appear, they’re capable of triggering mega slot wins.

Do different slot games have different odds?

Yes. Each online slot is different. Even if two games have the same RTP, they may have a different volatility score and payouts. These subtle differences mean the odds will vary from game to game.

Which slot machines have the best odds?

Video slots tend to have the best odds. Because these games feature five reels, multiple paylines and fixed jackpots, their RTP scores are often close to 98%. However, that doesn’t mean three-reel classic slots can’t be profitable.

Similarly, progressive jackpot slots may have slightly lower RTPs than video slots but the potential payouts are larger. Therefore, when you’re thinking about how to get the biggest slot machine wins, you need to weigh up all the variables and not focus solely on the odds.

Can you increase the odds of winning at slot games?

Technically, the answer is no. The potential overall return rate of a slot is fixed. Although there are some exceptions in games where certain choices you make can improve your RTP, it’s generally the case that everything is set in stone, because these games need to be fair. However, this doesn’t mean you can’t improve your chances of winning at slots. Basically, it all comes down to the choices you make outside of the game.

For example, selecting slots with the best RTP scores and lowest variance should help you pick up more wins per spin. Similarly, by betting an amount you can afford, you give yourself a better chance of staying active for longer. This, in turn, gives you more chance of realising the full potential of a game. So, while you can’t increase the odds of winning at slot games in direct terms, you can enhance your prospects with some smart pre-game decisions.

How Do You Pick a Winning Slot Machine?

Picking a winning slot machine is all about the details. By assessing a game’s statistics and payouts, you can get a better idea of its potential and, therefore, of how likely you are to win over time. Of course, nothing is certain in this game. However, if you can weigh things in your favour, you stand a better chance of picking up some prizes.

How to use a game’s payback percentage to pick the best slots

The best way to use RTP scores to your advantage is to go for the highest percentage possible. All slots should tell you what their RTP is. Your job is to find games with the best RTP. As we’ve said, this isn’t the only variable you need to consider. So, don’t assume that a game with a higher RTP than another is necessarily better. However, as a starting point for learning how to play slots, you should look for the highest RTP games first.

How does volatility help you find winning slot games?

In tandem with RTPs, you can use volatility scores to help ascertain how likely you are to win on any given spin. Again, this isn’t an exact science. However, low volatility slots are designed to release smaller payouts more frequently, while high volatility games tend to dispense large payouts less often. By assessing RTPs and volatility scores together, you can build up an idea of how likely slot wins are in a particular game.

Can you win consistently at slots?

No. It’s a harsh truth but an important one to remember. Even if you choose the best slots in terms of odds, variance and payouts, anything can happen when you spin. Yes, there are things you can do that may improve your chances of winning. However, all online slot games are random, which means you can never be certain you’re going to win or go on a winning streak.

What is the loosest slot machine?

For some players, the loosest slot machine is the one that hasn’t paid out any money for a while. Now, there is some logic to this as games always have to pay out some money. However, that doesn’t mean you can look for slots that haven’t released any prizes for a while and guarantee a win.

Do slots pay more at night?

No. Even though some might argue that slots are more likely to pay at night because more people are playing, that’s simply not true. Slots operate on their own time, which means you can play whenever you like and expect the odds to be the same.

How to Find a Winning Strategy for Slot Games

As we come to the end of this guide on how to improve your slots strategy, let’s recap what we’ve learned so far. In short, the way to improve your potential is to make the right choices outside of a game. Indeed, once you hit the spin button, you’re surrendering all control to the casino gods. Therefore, it’s the moves you make before you spin that count. With that being the case, here are the steps you should take before you shoot for the biggest slot wins possible:

·         Step 1: Compare the paybacks of several slot machines.

·         Step 2: Increase your winning odds by choosing high payback slot games. You can do this by looking at a game’s RTP.

·         Step 3: Find the slot's volatility and choose games according to your preferences. Low volatility games will pay smaller prizes more often, while high volatility spinners will do the opposite.

·         Step 4: Play the demo versions of the games before placing your first bet. This will help you get a feel for how a game flows.

·         Step 5: Find slot games that offer free spins. Bonuses are a great way to increase your potential payouts.

·         Step 6: Place your bet and play for real money.

Slots Tips

Are online slots really random?

Yes. Even though each game has a predetermined return rate, the outcome of each spin is random as well as provably fair, if you play on reputable casinos. Of course, it’s not correct to say that slots are truly random because there’s an element of certainty i.e. the RTP is fixed. However, within the parameters determined by the RTP, everything is random and you won’t be able to predict when or how you’re going to win.

Can you tell when a slot machine prize will hit?

No. Although some people claim they can get a sense of when a game is going to pay out by tracking when the last win occurred, this is basically impossible. As we’ve said, each spin produces a random result within certain parameters. Even if you know a game’s RTP and volatility score, you can never predict when a prize will be unlocked or how much it’s going to be worth.

Is there a winning strategy for slots?

You never know when or how wins are going to strike, the only thing you can do is play consistently within your budget and hope that luck is on your side. Of course, you can choose games with better RTPs and, in theory, give yourself a better chance of making a profit. However, if you really want to improve your potential, you should play at an affordable level and try to be fairly consistent.

How can I find a slot’s payback percentage?

The best way to find a slot’s payback percentage is to open the settings/payout menu. If it’s not listed there, you can often get this information by reading reviews of this slot.

What is the average slot machine payout?

Online, the average slot machine payout rate is between 95% and 98%. Offline, the RTPs are much lower and will often be around 90%-92%. In terms of the average jackpots, these will vary depending on the game you’re playing. Progressive jackpot slots will often have six or seven figure payouts, while video slots usually offer five and six figure prizes.

What is the maximum amount you can bet on slots?

The maximum bet on slots will vary but it’s rare to find games with limits higher than 500 coins per spin.

What is the minimum amount you can bet on slots?

The minimum amount you can bet on a slot is 0.01. Although each slot will have its own betting limits, there are games that allow you to wager 0.01 credit on a single payline. Therefore, your total stake will be 0.01. Of course, if you add more paylines, your overall bet will increase. However, as a minimum, it’s possible to play certain slots for as little as 0.01 coin.

Is betting the max the best slot strategy?

Slot machine winners aren’t defined by the amount they stake. Indeed, if you look at some of the biggest slot wins in history, the winners only wagered a small amount. Therefore, you shouldn’t assume that betting big will improve your chances of winning. However, when it comes to multiplier wins, these are affected by your stake. The most important tip we can give you on how to play slot machines is to spend what you can afford. As long as you stick to your limits and bet responsibly, you’ll have fun and, if you’re lucky, wins will come your way.

Do I have to download software to play online slots?

No. All the best online slots are available online and via mobile without any downloads required. There are ways to download and play, particularly in the mobile arena. For example, you can access Paddy Power’s top slots by downloading our iOS or Android apps. However, this isn’t necessary. If you want instant access, you can use our optimised software to play for big slot wins whenever and wherever you like, via your computer, tablet or mobile browser.

Can casinos change payouts on slot machines?

In some cases, they can. Although developers tend to set the parameters for a game, there are times when a certain amount of personalisation is possible. However, it’s important to note that casinos can only tinker with payout percentages and the like. In other words, they will have to work within certain parameters.

In fact, as well as software developers setting the tone for a game, gaming regulators also have a say in the matter. Although there are no laws regarding minimum and maximum slot RTPs, there are generally accepted standards. Therefore, if an operator was offering payouts that seemed totally unfair, it would likely prompt a regulatory review.

Can you win at slots with little money?

It is possible. In fact, this is the main reason why people play slots. Because you can win many times your stake from a single spin, these games are great for beginners. Of course, we can’t say for sure that you can wager a little and win a lot. However, some of the biggest slot machine wins in history have come from small bets.

If you want to put this to the test and see what winning slots are all about, create your personal account at Paddy Power!



All slots have different payout ratios, which means jackpots hit at different rates. In general, you can say that the chances of hitting a slot jackpot are thousands-to-one.


For the largest slot wins, you need to play progressive jackpot games. The main reason these games offer the biggest slot payouts is that every bet you make contributes to a communal prize pool. As more people play, more money is added to the pot until someone wins. This dynamic means that jackpots can reach epic proportions in a matter of weeks.