Modern casino slot games are controlled by computer chips and software, and the win %s are pre-programmed into the gaming software.
Casino slot games have Random Number Generators that are eternally generating combos, even when the slot machine game is not currently being played.
Running synchronously with the random # generator of the casino slot machine is the payout %.
The pay out percentage controls just how much the slot machine game will payout, for e.g. the payout percent might be ninety per cent, which means the slot machine will pay out ninety percent of all the bets played, … the casino only gets to keep 10 per cent.
This is not to say that each and every time you bet 10 credits you will receive 9 in return – where is the fun and exhilaration in that? Instead, the casino one arm bandit just will not payout for a little while, and then suddenly fire up a hot streak and you might draw the big jackpot.
The pay off percentages will most likely vary between the different games and several of the extremely acclaimed casinos, for instance Golden Online Casino, which hands out a pay out rate of up to 95 %!
So, in essence, the slot machine 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 indistinct per cent of all the wagers placed.
The casino one armed bandit software controls any part of the machine, from the blinking lights to the spinning of the reels.
When you hit spin on the one-armed bandit, a combination is developed by the RNG which corresponds to the pictures on the reel.