A casino jackpot is a large sum of money that’s won on a slot machine. The odds of winning are inversely proportional to the jackpot’s size: a smaller jackpot has higher odds, while a larger jackpot has lower odds.

Unless you’re playing a progressive jackpot machine, the odds of winning are slim. These machines are connected to a central jackpot system, and a small percentage of every bet is deducted to the jackpot fund. These jackpots can be large, but they also come with a high house edge.

The largest jackpot ever won at a casino was $39.7 million, on a Megabucks machine in Las Vegas in 2003. However, most jackpots don’t reach these levels and are often smaller than expected.

When you hit a jackpot, the machine will make an audible noise and flash a bright light to let everyone in the gambling hall know that someone has won big. It will also display the amount won, which is designed to entice people to play.

Generally, you’ll need to verify your win, inform managers, fill out a W-2G form, and handle a lot of other paperwork before you see any of the money. Depending on the size of the jackpot, this process can take hours, and you won’t be allowed to spend a penny until you show a government-issued ID. If you’re a nonresident alien, the IRS will get a cut of your jackpot. It’s also worth noting that casinos are required by law to keep your identity confidential.