Progressive slots are slot machines that accumulate towards an additional jackpot over and above any amount that you may actually win on the machine. A small percentage of each players bets go towards this jackpot. Hundreds of online gambling sites offer the same progressive slots, and the progressive slot wager portions from all of these sites are centrally pooled to make up the grand jackpot, which can be won by playing at any of these sites. At land-based casinos the same principal applies, the difference being that a number of physical slot machines are linked together to form a progressive slot machine network, paying out a progressive slot jackpot beyond the payouts that each machine makes to players on their own.

There are 3 types of progressive slot machines in real-world casinos. Independent progressive slot machines are not linked to other machines, but a portion of each bet is still taken and put towards a super jackpot that the individual machine will pay out. In-house progressive slot machines are a number of machines linked in the same casino. Wide-area progressive slot machines are large numbers of machines from different casinos all linked together.

The drawback that a slots player must be aware of is that because a percentage of each bet is taken and added towards the progressive jackpot, the actual payout that each individual machine will make per winning bet is a little lower, as the actual bet amount at the individual machine is lower, due to the portion that has been removed. For this reason, it is wise not to make progressive slot machines your main form of slots play. Rather play them selectively with a certain portion of your bankroll. Thus you can still be in with a chance of the big progressive jackpots, but most of your slot play pays out at the full bet rate.