How do online slot machines work?

Online slot machines have become a tremendously popular form of entertainment in the digital age. Especially following the Coronavirus pandemic where land casinos were widely impacted and forced to close.

Just like physical slot machines, online slots offer vibrant graphics, exciting themes, and potential big wins to everyone. No wonder why they attract millions of players worldwide on a regular basis.

However, have you ever stopped to wonder how these online slot machines actually work?

Well, in this article, we will delve into the mechanics behind these captivating games, so keep reading!

Cleopatra Online Slot Machine

Random Number Generator (RNG)

The first and arguably most important thing you should know about how online slots work is the RNG. This is a technology that lies at the heart of every online slot machine and does exactly what it says: generate random numbers.

The RNG of every online slot generates random numbers for every spin. By doing so, it ensures that the outcomes of each spin are truly random, thus replicating the unpredictability and fairness of a physical slot machine.

This sophisticated algorithm generates the necessary sequence of numbers at an incredibly rapid pace and determine where the symbols land on the screen. So, immediately after you hit the “spin” button, it selects a number that corresponds to a specific outcome, either a winning or losing combination.

Paylines and Symbols

As you may already know, all online slot machines feature different symbols and paylines that determine the potential winning combinations.

Prior to initiating the spin, players typically have the option to customize the number of active paylines and determine their preferred bet amount per line. Once the reels come to a halt, the symbols align on the screen, and the game software evaluates the result using the predetermined paytable.

If the symbols form a winning combination on an active payline, the player receives a payout according to the game’s rules. f not, they can always try again!

Return to Player (RTP)

RTP is the percentage that represents the average amount of money a slot machine will pay back to players over time. This is another crucial concept you need to understand to know how online slots work.

For example, if a slot machine has an RTP of 98%, it means that, on average, players can expect to win back $98 for every $100 they wager.

Nonetheless, you need to keep in mind that RTP is calculated over millions of spins. Meaning that individual sessions can deviate significantly from this average.

In-land slot machines also have an RTP percentage. However, if you aren’t knowledgeable enough about that specific slot (or don’t have internet access to Google it), you won’t know if your chances of winning are good or not.

On the other hand, online slots usually tell you right away what its RTP is, making them far more convenient.

House Edge

Given the fact that it’s all random, you may be thinking that the online casino could lose money with their slots, right? Well, not quite.

All online casino games are designed to provide the house with a built-in edge that diminishes the chances of potential payouts and ensures that the casino makes more money than it pays out in the long term.

Of course, some players will be lucky and win a decent amount of money from an online slot machine. But for that person to win, there had to be many other previous players that lost, that way giving the casino the possibility to hand out the prize while still making a profit.

While the house edge ensures the casino’s profitability, it does not guarantee that players cannot win or enjoy successful gaming sessions, so keep that in mind!

Regulation and Auditing

Many players may feel skeptical about playing on online slot machines thinking they’re the perfect place to scam people, but that actually couldn’t be more wrong.

All reputable online casinos are subject to stringent regulations and auditing processes to ensure fairness and integrity, making them a safe place for both casual bettors and gambling enthusiasts.

For example, the New Jersey Division of Gaming Enforcement is the agency in charge of assessing the software used by online slot machines from NJ online casinos. This is something they regularly do in order to verify every online slot’s randomness and compliance with industry standards.


Online slot machines have evolved from simple mechanical devices to sophisticated digital games. And while their online version may seem extremely complex, they’re actually pretty similar to physical machines in terms of functionality and performance.

They both ensure fairness through an RNG, have an already set RTP, and benefit the house in the long term. The only difference from one and other is the fact that you can access one from the comfort of your home, and the other one requires you to visit a crowded casino, that if you’re lucky enough to have one near you.