How Do Slot Machines Work

Slot machines play a large part in the offline and online gaming industry, generating billions of pounds in tax revenues each year, and providing millions of employees with jobs. They also continue to draw fans both old and new from around the world.

However, the slots that you see today are remarkably different in both their appearance and their technological makeup from the one-arm bandits and fruit machines that were first produced back in the late 1800s.

If, like many players, you’ve ever found yourself wondering, “how do slot machines work?”, we’d love to help you understand more.

In this article, we take a brief look at the history of slots, how they work, when and where they were introduced, and how they have gone on to play a major role in modern-day gaming.

Original Mechanical Reels

The very first fruit machines and one-arm bandits were invented at the turn of the 19th century.

The one that was first to use mechanical reels was called the Liberty Bell, and it was created by a car mechanic from San Francisco called Charles Fey in 1895.

Like the fruit machines that started appearing in pubs and social clubs in the 1960s, Fey’s Liberty Bell used a set of familiar symbols. In this case, the gold bells paid the most, while hearts, diamonds, spades, and horseshoes could produce smaller cash prizes.

Later mechanical slots extended the range of pay symbols to include fruits, bars, and sevens.

With original slots, there were three metal hoops (a.k.a. reels) inside each machine, each of which contained ten symbols. All the player had to do was pull the lever at the side of the machine to spin the reels. When the reels stopped spinning, a prize would be awarded if three matching symbols appeared across the centre.

You can still play mechanical slots today in many popular land-based casinos, particularly in the US where they’re more commonly referred to as one-armed bandits.

Modern Day Slots

The Liberty Bell led to many more mechanical slots appearing throughout the US and Europe, which subsequently led to the pub fruit machines that quickly became just as popular in the UK in the 1970s and 1980s.

In 1965, Bally’s Money Honey became the world’s first fully electromechanical slot game. It was operated via a level although the reels were operated electronically rather than mechanically. However, the first, real modern-day slot wasn’t launched until 1976.

Fortune Coin was developed in California and it used a 19-inch Sony TV screen for its display. Players first got to set eyes on it in the Las Vegas Hilton Hotel. After some minor alterations were made to the prototype, it was accepted into casinos on the Las Vegas Strip.

The company which developed the Fortune Coin video slot was bought out by what is commonly considered to be one of the world’s most famous online slots developers, IGT, in 1978.

In the mid-90s, WMS launched a video slot called Reel ‘Em, and what made it extra-special was its bonus game. No previous slot had ever featured a bonus game that played out on a different screen.

In the same decade, video slots really took off in bricks-and-mortar casinos where they occupied almost three-quarters of the floor space and contributed approximately 70% to each casino’s profits.

Online Slots

When people started taking advantage of the newly-invented internet in the 1990s, online casinos swiftly followed, and with them came online slots and casino games.

To start with, online slots looked very much like their physical counterparts with similar symbols and the same number of reels.

Thanks to a growing number of software developers, however, we’ve since seen 3-reel slots followed by 5 and 6-reel slot games, progressive jackpot slots, and 3D slots. Newer additions include extra bonus features such as free spins and pick-and-click rounds, and differing game mechanics such as Tumbling Reels, Megaways, Cluster Pays, and Multiway-Xtra.

Sophisticated Random Number Generator (RNG) software is used in every slot game. This software creates random sequences every millisecond to ensure that every player receives a truly fair and random outcome. Each slot also has a pre-determined RTP (Theoretical Return to Player) which affects how likely the player is to receive their stakes back over an extended period of time.

Instead of having to pull a manual lever, players can click their mouse button or tap their mobile device’s screen to spin the reels. Any winnings are automatically credited to the player’s casino account balance.

At Gala Spins, you can choose from hundreds of slots, including classic slots that aim to replicate old-school three-reelers, progressive jackpot slots, and 3D slot games.