I ran across a website a while back that said something that we all know, intuitively: "A roll of the dice is not fair." Literally!
According to the website, if you roll a die (that's the singular of dice) 10,000 times, the side with one dot will come up 1,654 times, and the side with six dots will come up 1,679 times. That's not a great difference, but it's enough of a difference to make the casino business immensely profitable. If you play long enough, the casino will win -- always. The odds are against you. It isn't fair.