With so many features, dazzling lights and moving parts, it’s no wonder more and more players want to know how to play slots. Sure, you can spin and go. But how much do you really know about the software beneath your favourite slot?

In this slots guide, you’ll learn the basic slots rules, including how they pay out and how the most popular slot features work.

A quick slots explainer

If you’ve never played a slot in your life and you’ve got 2 minutes to spare, here’s all you really need to know about how to play slots online.

What are slot machines?

A slot machine is a gambling game which uses reels and symbols. They get their name because early slots in live casinos were played by placing a coin in the slot. Players inserted their coin or token, pulled a lever and spun the reels. If the symbols on the middle line matched, they won a prize.

The earliest slots used only 3 or 4 slot symbols and each one had a different value. Modern video slots now use 10 or more symbols, which makes them both visually exciting and gives a larger range of payouts too.

Slot Machine Features

For all the snazzy graphics and gameplay, slots players care most about the payout potential and the ingenious path to cash prizes.

Online slots have a maximum multiplier per symbol, and because you can hit more than 1 payline win on the same spin, a maximum total win per game too. This number is often set by the casino, so they can manage their liabilities.

With thousands of slots to choose from at PlayOJO, you’ll find a very wide range of payouts. Older classic slots often have relatively low maximum wins. Rainbow Riches has a maximum win per payline of just 500x, but it remains one of the most popular slots of all time, so that modest prize clearly does it no harm at all!

The standard for new slots these days is the 5,000x top payout you see with games like Wolf Gold and Book of Dead. At the top of end, the highest payout games like Starburst can have a 50,000x max win, and there are jackpot slots with millions of pounds up for grabs.

If you want to know how to win slots prizes and what’s up for grabs, the paytable is the place to go. Some paytables show you the prizes in coins, while others use a cash figure based on the coin value you’ve chosen. This paytable from the legendary Gonzo’s Quest slot shows us how many coins you’ll win if you match 3 or more symbols on a payline.

Paytable from Gonzo’s Quest

But knowing what you can win if you hit 5 cherries is just one piece of the puzzle. Even though a slot has a 5,000x symbol win and a £250,000 maximum payout, the way prizes are awarded has more to do with software settings called RTP, volatility and hit frequency. To understand how a slot decides who wins, how often and how much, you have to go under the hood.

Online slots rules

For all their rules and features, online slots are one of the easiest casino games to play. Many modern slots have been simplified so much that you only need to pick your stake per spin and play.

Take Dynamite Riches for example. Pick your stake, match 3 symbols on a win line and get paid. Sounds easy! But choosing your stake isn’t always that easy, and it makes a real difference to how any wins are calculated.

Dynamite Riches Slot

How to bet

Before you can hit spin, you may need to choose a handful of important settings.

  • How many paylines to play?
  • How many coins per line?
  • What coin value?

Together, they all have a bearing on your total bet size and what your stake per line is. This figure is then used to calculate any wins.

Here’s a classic scenario in the Wolf Gold slot. This is a slot with 20 fixed paylines, but you do get the chance to toggle the total bet amount as well as the coins and coin value.

Wolf Gold Slot

Changing the number of paylines you want to play will obviously have a major impact on how often you win, and how far your bankroll will stretch. Betting more coins per line, or increasing the value of higher value coins, won’t usually change the odds of winning. They are merely a way to set your stake so you play at a level you can play safely.


It’s worth taking a moment to cover this useful feature, as it can save your fingers endless tapping if you play slots a lot.

A single slot spin – assuming you don’t win or hit a feature – will take less than a second. If you’re playing a highly volatile slot with a low hit rate, you might go many spins without any action, and that can feel physically repetitive (though I’m not going to claim playing slots is in any way exercise!).

If you want to know how to play online slots without the effort of continually tapping spin, the answer is autoplay. Simply set up the number of spins you want to play, sit back and enjoy the show. You can create rules which interrupt autoplay, such as win or loss limits, as well as if bonuses are triggered. It’s my view that autoplay should only be used in conjunction with responsible play, so you are always aware of how much time and money you are spending.

How to win

Now we’re talking. Virtually every slot uses the same set of rules which determine how a win is awarded. They usually go like this:

  • Hit 3 or more matching symbols
  • On the same payline
  • From left to right
  • Starting from the 1st reel

Those first 2 points are easy. Get 3 or more of the same symbol on a win line. Some slots have 5, 3 or even just 1 win line, while others have 10, 20, 100 or over 100,000! Luckily, the game will do the hard work for you and highlight a line win.

Here’s a typical 20-line slot from Yggdrasil which explains the various possible win line combinations. Notice that pay lines always start from the left reel. To win, you’ll need the same symbol on at least reels 1, 2 and 3 with no gaps between.

20-line slot from Yggdrasil

There are exceptions to these rules. Some slots pay both ways, so you can make winning combinations from right to left.

Some slots don’t use paylines at all. In ‘cluster pays’ games like Golden Ticket 2, you need 5 or more of the same symbol in a cluster, meaning the symbols must be connected vertically or horizontally. In MegaWays slots, winning combos must still start from the 1st reel, but the symbols can be on any row.

There are other ways to win when you play slots. We’ll cover the basics in a moment, and there’s more detail about slots features in our other slots guides. The most common way to win is hitting 3 scatter symbols to trigger a Free Spins bonus or some other type of bonus feature. But ultimately, most of these features still rely on matching symbols on win lines.

Slot features

If you look hard enough, you might find an online slot with nothing but paytable wins. But these days, slots all have 2 or more bonus features which give the game extra depth, create the chance of bigger wins, and sometimes even add an element of interactive play.

Although this is by no means a complete list, here are the main slot features you’ll come across, and how they work.


These aren’t really a bonus or game feature, but along with the number of reels and rows, paylines are the most important feature of any slot.

At PlayOJO, we have thousands slots with fixed or variable paylines. The average online slot machine has between 10 and 20 paylines, but the race to add more reels and paylines has sparked some very cool innovations.

Here we have a classic slot design in Irish Gold, with its 5 paylines, alongside the modern standard, the 20-line Rainbow Riches. If you play more lines, you get more chances to win but you pay more too, so your bet per line should be lower.

I’ve already mentioned MegaWays slots, whose special reel mechanics that produce over 100,000 possible win line combinations. These games generate a random number of symbols on each reel from 2 and 7, and symbols need only appear on adjacent reels.

Cluster slots are the new frontier in slots that look and play like mobile game apps. Many games don’t even display the number of lines, as the possible combinations run into the millions.

But more paylines doesn’t guarantee more fun, and some of the most popular slots have simple game mechanics and feature sets. Starburst is the world’s no.1 slot and it has just 10 paylines, as does Fishin’ Frenzy. Maybe it’s what you do with your paylines that counts!


Everyone knows what a wild card does in card games, and it’s the same deal with slots. Virtually all slots have a wild symbol which, as the rules always say:

“Wild substitutes for all other symbols except the scatter”

In English, this means a wild symbol can pretend to be any other symbol, and they come in super handy when you’re trying to make winning combinations. The only time they can’t be used is with special scatter symbols that trigger bonus games.

In the last few years, we’ve seen some awesome mutations of the classic wild symbol, from stacked wilds to sticky wilds that stay in place for future spins, expanding wilds which fill the entire reel, and many more.

Scatters & Free Spins

If you’re designing a modern online slot machine, wild are an essential feature but Free Spins aren’t far behind. Developers had to come up with a way for players to access bonus games, and the scatter was born.

A scatter is a symbol used to trigger a bonus, feature or mini game. Usually, you’ll need to land 3 or more scatter symbols anywhere on the reels. The standard approach is to award 10 Free Spins if you hit 3 scatters. Some games award more Free Spins for each additional scatter.

Once you’ve triggered your Free Spins game, the slot will autoplay your spins and count up the total winnings during the round. Slots often save their best graphics for these Free Spins rounds, and they’re also a chance for developers to introduce more special features.

The more exciting and rarer the Free Spins bonus, the more time players will spend trying to trigger it. Go figure!

Progressive jackpots

When you play a slot with a progressive jackpot, a small percentage – often as little as 1% – contributes to a pot which keep growing until someone wins it. It’s then reset to a ‘seed’ amount funded by the casino.

Casinos have been using player-funded progressive jackpots for decades across many types of gambling, but slots are the perfect vehicle. Internet gambling is a truly borderless form of entertainment and players from all over the country, and even the world, can create massive jackpots in days, let alone months.

There is no one way to win a jackpot, and it’s best to check the games rules before you play. Most involve some sort of random award, and some require you to play a minimum number of coins to be eligible.

By their nature, progressive jackpots dial up the volatility, taking a little from everyone to pay out one huge prize.

This is how records are broken and millionaires are made, but you should also be aware that the trade-off of playing for millions is a slightly worse payout model throughout the rest of the game. Understanding this relationship is an important lesson in learning how to win playing slots.

We have moved very quickly from slots with their own jackpots to collections of slots that feed into the same jackpot, and even a developer’s complete slot portfolio where all of their games share the same jackpot.

You might not get the best slots RTPs, but the draw of progressive jackpot slots is obvious.


A multiplier is a simple but exciting way to create the possibility of far bigger wins, usually during a bonus game. Multipliers of 2x or more can randomly appear on reels, and if they form part of a winning combination, the paytable win is multiplied.

Games like Thunderstruck II were among the first to use multipliers to spice up their bonus features. Here you can see random multipliers of up to 6x, and multipliers that go up with consecutive wins.

Thunderstruck II Slot Multiplier

Reel modifiers

This is a category of bonus features that involves the changing of existing symbols on the reels to create wins. Mystery symbols populate the reels with random symbols, while symbol swops can reduce the number of different possible symbols, increasing the chances of a win.

Other modifiers involve adding wilds or multipliers to reels, or supersizing symbols to cover more of the reels.

Cascading reels AKA avalanche

If you’ve ever played Candy Crush, you’ll know how much fun a chain reaction feature can be. In slots terms, any symbols involved in a winning combo will disappear, leaving the symbols above to drop down. If the new configuration creates a win, the chain keeps going and the wins rack up, all from the 1 spin.

Check out games like Bonanza, Rise of Olympus, all MegaWays slots and most cluster games such as Jack in the Pot to see this feature in action.


That’s your lot for the ultimate guide to slots. What we haven’t covered so far, isn’t worth knowing! Now you know how to choose from thousands of slots, and how to play slot machines in order to have the most fun and give yourself the best chance of success.


Why are slots popular?

Slots may have been around since the turn of the 20th century and they became a staple in UK pubs for decades. But thanks to advances in technology, they’re now in a totally different league. You only have to play games like Guns n’ Roses to see how far slots have come.Slots are the most popular form of online gambling and in Vegas, more people play slots than any other table game. To the uninitiated, they look repetitive, and their sounds can drive you mad. But millions of gamblers across the world love to play slots for a number of reasons. There’s an incredible amount of choice, modern slots have impressive graphics and design, and you can play for small stakes for the chance to win bigger prizes than you’ll find in other casino games.

How do you play slots for beginners?

We covered the basic rules of slots in just 5 steps earlier, but let’s boil it down even further shall we! Fire up a slot, make sure you’ve got some cash in your account and SPIN! Couldn’t be easier. If you’re just starting out, penny slots are a good way to learn.

How do you win on slot machines?

There are 2 answers to this question. First, the literal interpretation. Match 3 or more symbols on a winline. Now for the reason most people ask this question. How do win at slots? Well, with a built-in house edge of 3-5%, you’re unlikely to beat the game in the long run. There is no slot machine strategy that can deliver a consistent profit. But with a bit of luck, anyone can run good in the short term and walk away a winner. Just don’t bank on doing it again!

How do online slots work?

Online slots are powered by computer software which produces a range of possible wins and losses using a random number generator. Slots each have a stated payout percentage that they are designed to deliver over a very large number of spins.

Can you tell if a slot is about to pay out?

Slots are random by design and it’s impossible to predict when they’ll pay out. Even if you know a slot has recently paid out a large sum to another player (or even to you), that doesn’t mean it will stop paying out for a while, because a slot’s payout rates are calculated over millions of spins.

How can I increase my chances of winning on slot machines?

That’s the million-dollar question, but there’s no million-dollar answer. By and large, online slots are pure luck, so there’s no in-game strategy you can use to tip the odds in your favour (however firmly or fast you hit the buttons on your pub fruit machine). But by choosing games with higher hit rates and lower volatility, and making sure you get the best deal when you play, you can put yourself in a position to play longer, bet sensibly and increase your chances of experiencing a win. There are lots of myths around how to change your odds of winning on old-style pub fruit machines (and I’ve never found one that was true!). But there are no silver bullets to improve your odds when you play slots online.

Daniel Grant

Daniel Grant

Dan Grant has been writing about gambling for 15 years, and been fascinated by beating the odds for even longer. Now he’s on a mission to help others bet smarter and avoid the mistakes he made. When he’s not obsessing over bankroll strategy or counting cards badly, he’s hosting The OJO Show podcast.