I know that slots can be set to pay-off frequency percentage. When I worked at a casino a slot-mechanic showed me this (I was of course wasn’t’ suppose to know this). It is all done by computer and I think it was set by %.
So who sets that % ?
Fruit Machine Sites
A casino does not have access, by law, to the chips set. There is no such thing as a tight or loose machine. The payoff are based on a random number generator that runs every second of every day of every week of every year. It runs even if no one is playing the machine. The wins…and…therefore…the looses are purely random. I have hit $1000.00 on dollar poker machines three or four times in ten minutes. I have gone hours and hit nothing.