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Slots Paylines: How Do They Work?

slots paylines

Slot machines are one of the most popular casino games to play in the world, because of how easy they are to play and how attractive they are in terms of the sounds, lights and more. The atmosphere that slot machines create in a bricks and mortar casino can now be rivaled by the graphics and entertainment value of internet live casinos, causing a battle of the slots. But how do slots work? This is the million-dollar question! With a growth in technology and advancement in popularity of casinos both online and offline, there has been a huge evolution of many casino games. The most noticeable of which is the slot machines and their paylines.

Slot Machine Composition

No matter whether you’re playing an online video slot machine, or a traditional three reel slot, when you strip them back, their composition is more or less the same. Once you know the basics, you’re set to tackle any slot machine no matter where you are in the world.

How do slots work? All slot machines will have a balance, a display box, a paytable, reels, bet per line, number of paylines, maximum bet and play/spin button or lever. These are the core components of all slots. The true test of a great slot machine game is how all these elements combine to create the perfect slot game.

  • Balance — the amount of money in your account for use on that slot machine
  • Display box — a box which lets you see when and how much you win
  • Paytable — a table that will show how much you can win on a payline
  • Reels — part of a slot machine that shows the symbols, and spins
  • Bet per line — the amount of money that you want to wager per line for your next spin
  • Number of paylines — you can choose how many paylines you want to play (multiline slots only)
  • Maximum bet — bet per line x number of lines = maximum bet
  • Play/Spin — A lever or button that will spin the reels

Slot Machine Composition

How Do Slots Work?

Slot machine games are truly fascinating creations. Most slots feature 3+ spinning reels, each with a set number of symbols. Physical slots usually have at least 20 symbols per spinning reel, but when you add in digital technology, they can feature as many as 256 different symbols per reel. This means that there are millions of potential combinations of slot symbols that can come up on any given spin. The actual in-game mechanics of slots are governed by sophisticated computer programs known as RNGs. These random number generators instantly generate slots results for every single spin.

Think of RNGs as the computer equivalent of Lady Luck! But how do slots work? To be perfectly honest, it’s all in the RNGs. These computer algorithms are designed to mimic random outcomes as best as possible. With thousands of potential results generated per second, each of which is associated with different symbols, you can imagine just how complex the rules governing RNGs can be. As you are about to learn, slot paylines form an important part of how slots work. Sometimes you’ll be able to choose the number of paylines you wish to play (known as variable paylines), and at other times they are fixed.

All slots are characterised by volatility. The higher the volatility, the bigger the potential payday. But it’s never easy hitting mega winning combinations on slots. How do you win on slots is up to the size of your bets, the number of lines you play, and the RTP (return to player) percentage of the specific slot machine game. Every slot machine game has a house edge, and that house edge always favours the casino. Your job is to find a slot with a relatively low house edge and a high RTP. The house advantage is always lowest with games like blackjack. Slots are chance-based attractions, and have a higher house edge.
Can you now answer the question: How do slots work? If not, continue reading, we’re going to show you everything you need to know about slot paylines, and evolution of slot machine games through the ages. You may want to grab a beverage and a snack. We are going to take you behind-the-scenes in this slot machine tell all. Are you ready? Let’s spin up a storm!

What Is A Slot Payline?

A payline, also known as betting line or winning line, is a combination of symbols that results in a win, on a slot machine. Original slot machines only had one payline, and that would be won if three matching symbols created a horizontal line. When it comes to paylines, you can see how much your payline will win by looking at a paytable. Nowadays, paylines aren’t just horizontal, and can be in a huge number of shapes, from zigzag to trapezium.

Nowadays, the common number of betting lines is 25-30 paylines per slot, and it is often the first thought a game developer has when it comes to building a slot machine, as the different paylines lead to the prizes, bonuses, free spins and multipliers. Also, some slot machines allow you to choose how many paylines you want to play, also known as a free slot machine whereas others ensure you play all of them, known as fixed.

One thing to remember is that no matter what direction the reels spin, and no matter what number of paylines there is on a slot machine, a payline will always have to cross the same number of icons. For example, if you’re playing on a three reel slot machine, the payline will feature three symbols.

Knowing how to choose a payline is important when you sit at a slot machine. Variable slot machines will allow you to select a number of paylines which get activated when you start spinning. The slot paylines are numbered from 1 to the number of paylines on the machine, (with many being numbered 1-12) and you can choose how many you want. If you’re looking to have some fun then it’s usually best to keep the amount of paylines under 5, in order to keep your bankroll in check. However, those who play progressive jackpots tend to play as many paylines as they can afford.

What Is A Slot Payline?

World’s First Slot Machine Payline

Somewhere between 1885 and 1897, Californian car mechanic Charles Fey invented the first mechanical slot machine, which featured 4 symbols on 3 reels. This was known as the “Liberty Bell” and in order to win the highest payout (10 nickels), the player had to get three bells in a row. Many classic slots such as the Liberty Bell and others that followed featured just three reels and one payline.

What you might not know, is that Charles Fey invented the slot machine as a way to entertain his guests while they were waiting for their cars to be repaired. Now that’s good customer service.

Poker Gambling Machine

In 1891, Sittman + Pitt introduced the poker gambling machine, which is considered to be a precursor to the modern slot machine, but it is highly disputed between Sittman + Pitt and Charles Fey supporters which invention came first. Either way, neither machine came into circulation until 1899. The poker gambling machine was a game that looked similar in shape to a slot machine, but the payline was made up of winning poker hands. If the payline matched up, any winnings would be based upon what the establishment the machine was based in had to offer, such as free beer or cigarettes.

poker gambling machine

Electromechanical Slot Machines

In 1964, Bally Manufacturing produced the first electromechanical slot machine, known as the Money Honey. Money Honey took a major step in setting major differences between it and its predecessors, by featuring electronic parts rather than relying on springs, and added lights, sounds and the option to bet multiple coins.

Money Honey was also the first machine that could make automatic payouts of no more than 500 coins. It was at this point that some electromechanical slot machines began to slowly adopt more paylines, particularly with the introduction of five reel machines, as they began to adopt up to nine paylines.

Rise Of The Video Slots

In the 1970s, slot machines took a huge turn, with the growth of technology, and the first video slot, known as Fortune Coin was introduced by Walt Fraley. Although video slots began in the 1970s as a mimic to regular slot machines by only having 1 payline, this has now increased massively, alongside the number of themes and the technology involved in a video-slot machine.

Multi-Line Paylines

It was in the 1990s that multi-line slot machines became widely available and extensively popular. These machines have more than one payline, and reel slot machines commonly have three or five paylines. However, advanced video slot machines can now have anything from 9 — 243 different paylines. When more lines are involved there’s a higher chance of winning, as you’re covering a lot more ground.

The huge transformation of the mechanics behind a slot machine, have had a huge impact on the number of paylines that slot machines have, and now, multi-line paylines are generally the most popular forms of slot machines to play. This is due to the fact that you can maximise your chances of winning by betting on all of the paylines available, although this is not advisable if you want your bankroll to last.

Multi-line paylines

Payline Winning Chances

When it comes to betting on paylines, you can work out a strategy which can help you to take even more winnings. The amount of paylines on a slot machine can have a huge effect on your bankroll, winnings and enjoyment, depending on how many you want to play with. For example, if a slot machine has a 25 winning paylines, and you want to bet 1 pence on each payline, every spin will cost you 25 pence. However, if you bet on all of the paylines, you will dramatically increase your chances of winning. Although some slot machines have fixed pay lines, where you have to bet on all of the paylines, some are variable, meaning you can choose how many paylines you want to play, and how much you want to bet on each line. The less paylines you play, the less chances of winning you will have, but each spin will cost considerably less!

Payline Winning Chances


The evolution of the slot machine payline has been an interesting one, and now, if you’re not keeping a close eye on the paytable, you might even hear the chink of coins unexpectedly. It wasn’t until the 1990s when multi-paylines really had an impact, and now multi-paylines are commonplace. With a huge increase in the number of paylines, and technology evolving to introduce a higher number of reels and further ways to play on the slots, if you’re feeling lucky, you could be in with the chance to win a jackpot.