In sweepstakes-style slots, each spin should be unpredictable, even if the last few results looked unusual. For players, the question is not just ‘is it random?’ but ‘how is that verified?’
A certified random number generator (RNG) is tested by an independent lab to check for bias and repeat patterns. Certification focuses on both the random numbers and how a game uses them.
In Short: A certification report is designed to be repeatable, not based on one short play session. It looks for patterns that only show up over very large samples.
How RNGs Pick a Result on Every Spin
An RNG is software that generates numbers constantly, even before anyone presses Spin.