How Do Casino Slot Machines Work

How Do Casino Slot Machines Work

Slots are the most extensive game category in any modern online casino, and it is available to many customers; there are slot machines with different numbers of reels, paylines, and even cluster payouts. All slots have a particular structure and characteristics that provide stability and a certain probability of giving winnings. If you know how do casino slot machines work in the USA, it will be easier to find games that are worthy of your attention and test them out.

The Main Facts About How Do Casino Slot Machines Work

Modern video slots are successors of world-known one-armed bandits, which are still available these days in many land-based casinos, including Reno and Las Vegas. However, instead of the mechanical elements that launch the reels, modern one-armed bandits use electronic processing units stored on a developer’s server. There is a wide variety of slot machine categories, and all of them are different because of the unique stylistics implemented by gambling studios.

Slots diversity
Slot categories at the online casino

At the same time, the differences that can directly affect your chances to get a payout, are a few: these are RTP and volatility.

RTP and Volatility

If you play slot machines regularly, you can notice that the probability of combinations coming up varies significantly in different slots; volatility and RTP affect this criterion. RTP tells what part of the money spent in this slot by all gamblers the slot machine will get back in the long run. For example, playing the slot with the RTP of 97%, you will likely get $97 out of $100 spent, but remember that it is not guaranteed, as it applies to all players. RTP can vary from 89 to 99% depending on the characteristics of the selected slot; the examples of slots with the highest RTP are listed below.

Slot NameRTPDeveloper
Ragnarok98%Genesis Gaming
Rainbow Riches Home Sweet Home97.75%Barcrest
Rainbow Riches Fortune Favors97.75%Barcrest
Devil's Delight97.6%NetEnt

Check the payout percentage in the slot description or in the Information section; don’t forget that you can also use the provider’s website to find this data.

The higher RTP, the more funds you can likely get back while playing in the long run.

Volatility is another important criterion that affects the winning probability when spinning slot reels; it can be medium, low, or high, as well as medium-high or low-medium. Low volatility means you can count on frequent wins, but their size will be pretty small; high volatility means rare but significant winnings. Average volatility allows you to win regularly, and the winning size is quite good. Newbies usually choose slots with low volatility, which allows them to get a positive feeling from winnings more often, while high rollers prefer high-volatile titles hoping for the big win.

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Random Number Generator

All licensed slots have one thing in common: they use a random number generator to operate. RNG determines the sequence of game symbols that come up on the reels after you have made a spin; this result is absolutely random and does not depend on previous spin outcomes. One game with the same random number generator provides the same result, which indicates gameplay fairness and transparency.

Neither players nor the casino can affect RNG operation; independent gambling organizations check this criterion if the casino is legitimate.

So, your results while playing slots depend only on your luck: one day, you can enjoy a winning streak, while the other, there are no successful spins at all. This makes slot machines the game of luck, but how do they work in practice? There are several principles:

  • RNG determines a random sequence of numbers.
  • The math module builds a matrix of values indicating the position of each symbol on the reels.
  • The graphics processor reproduces mathematical calculations using symbols located on the reels.

Modern RNGs are characterized by high performance, generating thousands of random combinations per second, so in fact, the outcome is determined instantly after you have pushed the start button; spinning of reels is simply a tribute to traditional land-based slot machines.

Slot Payouts in the USA

Each slot machine has an informational section and a payout table: you can use them to get basic information regarding the gameplay features. Additionally, you can play in demo mode to check how casino slot machines work and what are your chances of getting a payout without risking your funds.

Odds Explained

The slot informational section also tells about what options are available in this slot machine, for example, bonus rounds, free spins, risk games, and so on. There is also a description of game controls you can use to set up the slot before starting its reels. If the title has several modes of spinning the reels, you can also learn about them from the section with brief game information.

Payout Tables

Each authentic title produced by Play’n GO, Pragmatic Play, Push Gaming, Red Rake, Red Tiger, Tom Horn Gaming, or other well-known providers has a payout table, which we recommend reading before starting the reels. It contains detailed information about what combinations bring the winnings and how you can form them.

The Coins of Egypt slot
The paytable in the Coins of Egypt slot machine

The payout table shows all combinations you can collect to get a payout; moreover, there are all symbols value indicated.

How Do Casino Jackpot Slot Machines Work

Among the most popular casino games are jackpot slots, which can be progressive or fixed. Slot machines with a fixed jackpot usually provide a relatively small amount of winnings; if someone hits the bank, it restores to the initial level.

The progressive jackpot constantly grows due to new bets made by players: a certain part of each bet goes to the prize pool, so the amount of winnings can reach six and even seven figures. If someone hits the progressive jackpot, it will take some time to increase to a solid size again.

Gambling Legislation

When choosing a gambling site, you should pay attention to its reliability and legitimacy. As for safety, a valid license should indicate the gambling venue is secured; many regulators worldwide issue these gambling documents, and several US bodies are among them, for example, the Gaming Regulatory Authority of New Jersey or the Nevada Gaming Commission. They check how casino slot machines work in the USA and other countries, do they use RNG, and so on; for this reason, it is better to choose the gambling venue that collaborates with the major providers.

Features of Mobile Slot Machines in the USA

Mobile slots work on the same principles as their desktop counterparts: you set the bet size and launch the slot, then RNG determines the sequence of symbols on the lines.

Free Spins in Slots and Other Bonuses

To attract players and diversify the gameplay, providers add various features and techniques, including free spins; to activate this round, you need to collect a certain number of bonus symbols on the screen. You can extend the bonus round in some games by collecting a bonus combination on the reels again; there are also slot machines in which you can purchase a bonus to start the game with free spins immediately.

Risk games allow you to double in winnings; in this round, you should guess the card color or suit or choose a card higher than the dealer’s card.

You can also obtain various bonuses in prize rounds provided in many modern slots; there may be several stages with different gifts and opportunities for getting additional winnings.

Betting Strategies

Having understood how slots work, we can conclude that betting strategies do not work in slot machines; the reason is simple: you can’t guess or predict the results of the RNG operation. All you can do is increase your winning chances: practice regularly and use bankroll management to keep your money for a long time.

Online Slot Scams

You should play for real money only on gambling sites you can trust. There are many fraudulent gambling sites on the web: they host scripted slots, do not pay winnings, or use titles from unknown developers without licenses. Check the casino security in advance, and if there are any hints it is a scam, avoid registering there.


To do this, you need to register and make a deposit using one of the provided payment methods.

When choosing a slot, please pay attention to its volatility, RTP, and the developer who has produced it.

Regular practice, adhering to your bankroll and bet limits, and the right choice of slot machines with the highest RTP can help reduce the risk of losing.

The list of the most popular slots includes Eternal Love, Lost Mystery Chests, Game of Thrones, Starburst, Coins of Egypt, and others.

Demo mode is designed for practice so you can test the slot before playing for real money.

Publication Author
Ashton Stewart
Author of articles
Ashton was born and raised in the USA. In 2012 he entered The University & Jepson Herbaria, University of California, Berkeley, and graduated in 2017. There he got acquainted with gambling and realized that there was not enough information about reliable websites on the Internet.
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