Modern casino one armed bandits are controlled by a computer, and the win percentages are preprogrammed into the software.
Casino Slots have RNGs which are continually generating combos, even when the slot machine is not being played.
Running collectively with the random # generator of the casino slot machine game is the pay out rate per cent.
The payout % controls how much the slot machine game will payout, for eg the payout percent might be ninety percent, meaning the slot machine will pay out ninety per cent of all the wagers played, … the casino will then get to keep 10 percent.
This is not to say that each time you bet 10 credits you will receive 9 in return – where is the fun … excitement in that? Instead, the casino slot machine game will not pay out for a while, and then suddenly go on a hot streak and you might hit a big top prize.
The profit percentages will definitely vary between the differing games and a couple of the most established casinos, e.g. Golden Online Casino, which offers a payout of up to 95 %!
So, in essence, the slot machine game takes all the $$$$$ played into it and pays it out to a few fortunate winners. The casino only gets to keep a generally low percentage of all the bets placed.
The casino slot software controls any part of the machine, from the flashing lights to the circulating of the reels.
When you hit spin on the slot machine game, a combination is set up by the RNG which is linked to the pictures on the reel.