Modern casino slot machines are controlled by computer software, and the win %s are pre-programmed into the software.
Casino slot machines have Random Number Generators that are continuously generating combinations, even when the machine is not being played.
Running side by side with the RNG of the casino slot machine is the pay out rate %.
The pay out percentage controls how much the slot machine will pay, for e.g. the pay percentage might be 90%, which means the slot machine will payout 90% of all the bets played, … the casino will then get to keep 10 percent.
This is not to say that every time you bet ten credits you will receive nine in return – where’s the fun and fascination in that? Instead, the casino slot machine game will not pay out for a bit, and then suddenly jump on a hot streak and you might draw the big jackpot.
The profit %s will very likely vary between the different games and a couple of the very acclaimed casinos, like Golden Online Casino, which hands out a payout of up to 95 percent!
Thus, in essence, the slot machine game takes all the money played into it and pays it out to a couple of privileged winners. The casino only gets to keep a generally low per cent of all the plays put out.
The casino slot software controls any part of the machine, from the flickering lights to the rolling of the reels.
When you hit spin on the slot machine, a combination is formed by the RNG which is linked to the pictures on the reel.