How do slot machines work?

Like to let off some steam in online casinos from time to time? Then, with every spin, you might wonder how the whole mechanism actually works. The truth is that slot machines still run on a similar principle as they once did, but their appearance has changed significantly in the more than 100 years of their existence.

Slot machines have come a long way

The first slots from the late 19th century were purely mechanical, with players turning the drums and reels using a manual lever. In 1894, Charles Frey came up with the important invention of automatic payout and also with the five basic playing symbols, which were diamonds, spades, hearts, horseshoes and the liberty bell.

At the beginning of the 20th century, players faced a challenging period riddled with restrictions, and the first electromechanical slot machine was created as late as in 1964. The reels of this slot had an electric drive and the lever could be dropped.

The popular video slots came along in 1976 and first appeared in Las Vegas. However, the online casinos we know today began to develop from 1994, when developers began creating sophisticated machines controlled by microprocessors. These have a lot of advanced features, from calculating the average bet volume to tracking odds.

Basic principles and division of slot machines

Playing on slot machines is relatively simple, which is why this type of gambling is so popular. Today, their reels work electronically and are controlled by software that stops spinning at a certain moment at the player's prompt. Since most of them are played for money, they are subject to strict regulations and can only be placed in licensed gaming rooms and casinos.

Slot machines can be divided into mechanical, digital and video slots. You will no longer encounter mechanical machines, at most in museums or retro arcades, but digital slots are still very popular and you can find them in casinos all over the world. The best thing about video lotteries is that they are connected to the entire network of machines and are played for the jackpot. A separate category are those in online casinos that you can play on your computer or smartphone.

RNG as the heart of the slot machine

The software device in slot machines can be referred to Random Number Generator or RNG. So whether you play slots, roulette or blackjack, this mechanism monitors all moves. And because it is based on random results, it no longer applies that players most often used to win when the machine was full of loose change and needed to empty out.

Nowadays, everyone plays according to the same rules and the probability of winning is not affected by previous results, the current jackpot or the frequency of bets. Stories of overtly benevolent machines overflowing with money are but a false tale. Just watch out for scammers and always check the credibility of the establishment.

You can read more about RNG in our article: What is RNG?

Payout Ratio or RTP

The calculation of the probability of winning is denoted by the RTP or Return to Player. This return or payout share is given by a theoretical value that is based on mathematical probability. This means that the larger the amount you spin, the closer you should get to the given value.

So RTP is the ratio of money that is returned to the players, so it is usually given as a percentage - we focused on the subject of RTP in more detail in this article.

Just be careful that it is based on the bet, not the turnover. But you don't have to worry about complex mathematics, current slots usually have this information listed in the game plans. But there are those math whizzes who want to check whether the numbers really correspond to reality.

Volatility of slot machines

But volatility, which you may know from the world of finance, also comes into play. And in the world of gambling, it has a similar meaning. The higher the volatility, the more you can win, but you also wait longer for your return. In contrast, slots with low volatility do not offer such high winnings, but you will score points on them more often. It therefore depends solely on you, if you prefer an adrenaline rush, or if you are willing to settle for lower amounts without the risk.

Symbols and winning combinations

All seasoned players know the traditional symbols that are based on card symbols. These include hearts, spades and diamonds. Bells, which have a long history, are also widely used. On one of the first slot machines from 1894, its author, Charles Frey, used images of green bells that marked the main win. Since the 20th century, lucky sevens, fruit trees, gum and other symbols have also been used - you can read more about symbols in the article Symbols on slot machines – why to get acquainted?

In addition to the standard symbols, there are also wild or scatter symbols. The so-called Wild symbol can be found on most slot machines in brick-and-mortar casinos and online, and it is there to replace other symbols and enliven the entire game. The only symbol it cannot replace is the scatter symbol, because it also brings various useful functions – for example, it triggers bonus games and helps create new winning combinations.

Bonus games and features

In addition to all this, wild symbols can have various modifications. Some are expanding, others are sliding, which means that they also reach other positions on the winning field or are applied in the next round. And another popular bonus is, of course, free spins, where you get to spin for free. You will also enjoy the multiplication functions or the purchase of symbols, all of which make the game more exciting. This article discusses how you can get bonuses and make the most of them.

Modern trends and innovations in slot machines

Online casinos, which you can access in a few seconds directly from your mobile phone, are a common phenomenon these days. However, current technologies go even further and offer experiences similar to visiting Las Vegas even while playing in a digital environment. The key to this is virtual reality, which makes you feel like you are playing real slots. According to experts, this is exactly the direction casinos will continue to take in the future. And hand in hand with that go virtual currencies and other new age developments.

As you can see, the era of slot machines is far from over. The gambling phenomenon that can adapt to any conditions is constantly changing and evolving. So you can try new games and trends at any moment, and you certainly have something to look forward to in the future.