One of the most common questions about online slot games and other casino titles relates to fairness—specifically, how results are determined and whether outcomes are truly random. The answer lies in the technology that drives the games, with Random Number Generators (RNGs) and related systems ensuring unpredictability and integrity.
Whether you’re spinning the reels using a welcome offer or accessing a promotion such as free spins no deposit, understanding how the underlying technology works offers useful insight into how game results are produced.
What is a Random Number Generator?
An RNG is the core component used in online slot games to produce outcomes that can’t be predicted. It’s a software algorithm that generates sequences of numbers continuously, even when no game’s being played. When you spin the reels, the RNG selects a number at that exact moment, and this number determines where the reels will stop.
In regulated markets, these RNGs are tested and certified by independent testing agencies. This process ensures that the outcomes generated by the software are not only random but also fair over the long term. The results aren’t influenced by previous spins, how much you bet, or whether you’re playing with real money or promotional features.
How is fairness maintained?
Online gaming providers operate under strict licensing conditions imposed by regulatory bodies such as the UK Gambling Commission. As part of these regulations, all RNG-based games must pass fairness audits before being made available to players. These audits involve mathematical analysis and simulation to confirm that outcomes align with the stated Return to Player (RTP) rates and that no bias is present in the results.
For players, this means every spin has the same chance of producing a win, regardless of previous outcomes or how long you’ve been playing. This is particularly relevant for promotional rounds, such as free spins, where there might be a perception that results differ. In reality, RNG technology treats all game rounds equally.
What about live casino games?
While RNGs are used in most digital slot and table games, some live casino games operate slightly differently. In a live dealer setting, such as live Roulette or Blackjack, outcomes are generated by real-time events. This could include a physical spin of a wheel or the dealing of cards. However, these games still rely on technology to ensure fairness and transparency.
Live games are streamed in real-time using high-definition video, and advanced camera systems capture every aspect of the gameplay. Software tracks outcomes, such as which number the ball lands on or which cards are drawn, and these results are relayed instantly to your screen. Although the mechanism isn’t algorithmic in the same way as RNG Slots, the fairness of the game is maintained through surveillance, auditing, and real-time monitoring.
Can you influence outcomes?
There’s a common misconception that player behaviour—such as switching games or increasing bet size—can influence outcomes. Because of how RNGs work, each spin or round is completely independent. There’s no memory in the system and no pattern that can be followed or predicted. Features such as autoplay or turbo mode simply speed up the process—they don’t affect the algorithm or change the odds.
Game features such as wilds, scatters, or free spin rounds are triggered based on random calculations at the time of the spin. If a promotional offer gives you access to free spins, those spins are processed in the same way as any regular spin. The game engine doesn’t distinguish between promotional and paid rounds when calculating outcomes.
Independent testing and certification
Most reputable game providers use third-party testing companies such as eCOGRA, iTech Labs or GLI to certify their games. These companies test the RNG software, verify the RTP percentages, and ensure compliance with regulatory requirements. Once a game’s passed, it’s awarded certification, which is often visible within the game interface or on the provider’s website.
These tests aren’t one-time events. Game software is regularly audited to ensure continued compliance and to identify any potential issues that might affect fairness or randomness.