The use of a Random Number Generator ensures that the machine will always have a random outcome. And although it’s true that casinos can adjust the returns by tweaking settings, this will never result in setting up ways to interfere with the RNG. If a casino holds an official license from a strict regulatory body (like the UK Gambling Commission, Malta and Gibraltar) this means that their RNG has been inspected for any shady practices. This, in addition with a third party audit certificate is a sure sign that what you’re playing is definitely not rigged.