The first progressive jackpots appeared in the 1980's when first microchips were built into slot machines. Linked progressive slots appeared in 1986.

Progressive jackpot is the highest possible payoff in any game. Most of the time it can be found at slots and video poker, but there are now jackpots in blackjack and other games. The amount of the jackpot increases with each bet placed in the machine. The prize grows until someone wins it and if the jackpot is on the linked machines the moment it is won it becomes unavailable for the others.

In progressive slots, more than a half of the money put in is paid out as wins, while less than a half is kept by the casino and the left part is added to the jackpot. If you are playing a machine with $5 bet, from the each bet $3.50 is a payback, $1.25 is kept by the casino while 25 cents go to the jackpot.

This way, the casino pays back approximately 75%, but this is just an example, as in reality a good casino pays back 70%-87% and online casinos pay back 89%-99%.

There can be no limits for a progressive jackpot as it can go on growing until someone wins it.