What is RNG at an online casino?
Last updated:
RNG stands for Random Number Generator. In online gambling it refers to the algorithm that determines the outcome of every game, from slot spins to card deals to roulette wheel results. It ensures each outcome is unpredictable and independent from previous results.
How it works
Casino software uses a Pseudo-Random Number Generator that applies a mathematical formula to a constantly changing seed value, producing a stream of numbers thousands of times per second. Each number corresponds to a specific game outcome. The moment you click spin or deal, the current number is captured and converted into the result you see on screen.
Certification and trust
Licensed online casinos use RNGs that have been independently audited by testing labs like eCOGRA, iTech Labs, or GLI. These labs verify that the statistical distribution of outcomes matches the game’s published specifications. Regulators require ongoing certification, so licensed games are continuously monitored for integrity.
Ben Barber got into the gambling industry through the poker rooms of London in the early 2000s. After building up a solid grounding in casino, sports betting and poker, he made the move to Malta where he spent close to a decade writing for some of the biggest affiliate networks in the region. A few years ago he relocated to Bali, which shifted his focus toward website strategy and affiliate marketing. The casino side never really left, though. He still writes reviews, how-to guides and in-depth pieces on everything from slots and live dealer tables to crypto casinos and sweepstakes sites. His approach is fact-first: help players understand how online gambling actually works before they deposit a cent.