loader search icon

Complete guide to understanding RNG and casino games

Published by Stelly | December 19, 2023

The success of online gambling lies in the fact that players trust their games to offer fair outcomes. A fair outcome means that neither the house nor the player can predict ahead of time who will win, which makes each spin of the reels or choice to draw another card a true gamble.

However, as you can imagine, this means that each roulette wheel spin or game of video poker needs to offer players an outcome that is 100% random. But how can online casinos guarantee a random outcome while balancing other gambling realities like RTP (return to player) percentages and the house edge we know is true of any casino game?

In this guide to Random Number Generators (RNG), we will delve into what it takes to deliver truly random gambling results and how this small but crucial piece of technology allows online casinos to be both fair and profitable at the same time.

What is a Random Number Generator?

A Random Number Generator in land-based casinos is a microchip that processes an excessive number of calculations per game using seed numbers and other unknown variables to deliver a near-instant outcome. The casino game, such as a slot machine, then decodes the outcome, which can either be a winning reel combination or a losing one.

What is RNG?
A guide to explaining how RNG (Random Number Generator) works.

In a land-based casino setting, this is known as a True Random Number Generator or a Hardware Random Number Generator (HRNG). It is called this as it uses a physical rather than a digital process to create the entropy needed to produce truly random results in the real world.

In an online casino, there is no need for a physical chip. Instead, a Pseudo Random Number Generator (PRNG) determines each of these outcomes.

A PRNG is a powerful piece of code that sits on the secure gaming server hosted by the casino software provider, not the casino and delivers a result each time you spin a slot reel or play another poker hand.

The software is entirely agnostic of whether the result it has just delivered is a win or a loss; it simply provides a coded outcome to the casino interface and moves on to the subsequent request. It does not track the wins and losses of individual players in order to determine who should win or lose next. Your success at gambling online is pure chance.

How do casino games apply RNG technology?

The casino game and the on-screen action you experience, such as Walking Wilds, cascading reels, and even free spins, are all part of the theatre of online gambling.

The stark reality of online casino games is that a secure gaming server receives a notification of a new game, a random result is returned, and a win or loss is recorded on the server.

A blank screen simply returning notifications saying “win” or “lose” every few seconds would be boring, which is why casinos design elaborate interactions using a variety of themes, settings, and even pop culture IPs, which are so popular with online slot players.

This instant response from the RNG software allows casinos to offer quality-of-life features like super fast slot spins and trusted results even when your software crashes, as the results of your game are recorded on the server within moments of you hitting the play button.

Can you trust the results of casino RNG?

Anything a well-intentioned person can make, an unscrupulous person can break in an attempt to gain an advantage over its users. This fact is one of the reasons that we always promote gambling at a licensed casino with trusted partnerships and a reputation for treating its players fairly.

In fact, being able to trust RNG is central to a thriving online gambling industry:

  • A secure RNG is needed to produce purely random results.
  • Random results are at the core of offering players fair results
  • Fair results ensure that the industry can grow with integrity

One of the first steps in ensuring that the casino RNG results you receive can be trusted is to play a casino that partners with globally recognised game developers. Since the results of each game you play sit on their servers, and they need to pass them to the casino, you can play with a high degree of comfort when the providers are companies like Pragmatic Play or NetEnt.

The next step is to ensure that the casino allows regular audits from reputable third parties, such as Technical Systems Testing (TST), Gaming Labs International (GLI), iTech Labs, and eCommerce Online Gaming Regulation and Assurance (eCOGRA). These bodies' entire business, and therefore their reputation, revolves around reviewing online gambling sites' business practices and gameplay results.

Balancing RTP and House Edge

A reasonable question that comes to mind when considering the stance that RNG delivers purely random outcomes is how this works in tandem with casino RTP and the fact that online casinos are known to have a house edge of around 4%.

There are several factors that influence the outcomes provided by RNG, with the most important for this conversation being the seed numbers. A pivotal part of the results generated by a PRNG is a series of encrypted seed values, which themselves are generated randomly.

These seed values allow for patterns in outcomes seen in hindsight, such as an RTP value of 96% or higher in slots, but cannot be determined in advance to ensure fair results.

Read more about this in our House Edge Guide.

There is also the design and format of the casino game itself, where the elements on the table and payouts for various actions directly impact the house edge. This reality is most easily seen in a roulette table, where the house advantage changes dramatically based on whether it is a single zero (2.7%) or double zero (5.26%) table.

While the results delivered by the RNG are purely random, they work within the framework of the game's odds and the seed values associated with that game to ensure results that align with promised RTP percentages and the advertised house advantage.

Do Live Dealer Games use RNG?

A common question when it comes to online gambling is where the recently burgeoning live dealer segment falls. While playing at an online casino, you live-stream a real croupier handling real-world casino elements like decks of cards or a roulette wheel. Does this cause a conflict with the casino's promise of genuinely random outcomes?

In this case the provider of the live dealer games is the one who is held to account for the results of each interaction. This accountability means they will implement the same PRNG outcomes as you were playing in a land-based casino. These results will, therefore, align with the outcomes offered by the casino in their terms and conditions.

Once again, this reliance on the live dealer provider to deliver fair and honest results is an important reason to avoid casinos that do not have partnerships with industry leaders like Evolution Gaming, who are the gold standard for live dealer gambling worldwide.

Gambling Strategies and RNG

Many sites claim to offer guaranteed strategies and formulas for beating the casino. However, as we have just discussed, the RNG mechanics behind every casino game do not allow this to be true.

In most instances, gambling strategies are aimed at outearning the odds of a game rather than allowing you to guarantee that each hand you play will result in a winning outcome.

Achieving this goal would mean hacking an encrypted gaming server and manipulating each outcome to a winning result. This is an impossible task because of the incredible security measures to protect these servers and the thousands of results delivered each minute.

Many so-called “guaranteed winning formulas” offer a high-level overview of a theoretical winning strategy using very simple math. However, once you begin to unpack phrases like “all you have to do is double each losing bet”, you will find that the bankroll needed to effectively outplay the odds, the house edge, and the RTP settings is simply untenable.

Our advice is to find a video slot, live dealer experience or table game you understand the rules of and enjoy playing and simply have fun.

Allow the RNG to do its job; if it is your turn to win big, it will happen. Until then, enjoy the effort and skill that has gone into creating an entertaining online gaming experience, and let the chips fall where they may.

Featured Guides

CasinoWow.com Cookies

We use 🍪 cookies to improve your user experience. By continuing to use this site, you are agreeing to our use of cookies as described in our Cookie Policy.



Be the first to get exclusive bonuses and WOW casino promotions! Get access to our new online casinos, top stories and special iGaming events for FREE.

Share this page across social platforms!