It’s unlikely to happen, but given slot machines are powered by power, there’s always the risk that a power outage can effect the machines. While many casinos have generators that kick in if such a scenario happens, they can fail, or the occasional situation can take place where the generator can’t kick in in time.
So, what happens? Players will be happy to know that games are designed to recover from a power outage to ensure the games in progress are maintained. If you’ve ever seen a slot machine that crashes reboot, it’s a similar process.
Each game is designed to retain information that helps it understand where it is in a given cycle, whether it’s idle with credits, in the middle of a spin, or inside a bonus. If a power outage occurs, the game will come back exactly where it left off.
What does that look like in practice? If it’s simply credits in a machine, once power is restored the machine will boot up with the credit balance accurately reflected. If power is going to be out for a long window, casinos may not make a player wait, but will instead take down a customer’s information so they can return the money to them once the machine has been verified.
If a jackpot was pending before the power outage, it’ll still be pending after.
If a spin was in progress, the game will complete the spin. Remember, a spin is determined at the time you hit spin, not at the time the reels stop spinning. So the game already knows what the outcome will be.
Finally, if a bonus was in progress, the game will have recorded what had happened to that point and will restore the game to that point. If it’s a non-predetermined bonus, like free spins, it will still replay what’s happened before resuming the bonus; this avoids someone intentionally tampering with the power on a machine to try to get a better outcome. Any remaining spins would then play out like normal.
As such, a power outage works out to be more of a nuisance than anything else, but rest assured the machines should bring you right back to where you were before the power interruption.