A progressive jackpot is a prize pool that grows with play. A small share of each qualifying stake, the jackpot contribution, is added to the pot until one player wins it, after which it resets to its seed value.
Progressives come in two main kinds. A local jackpot is fed by one game or one casino. A networked jackpot is shared across many casinos, which is how the largest pots are built; Games Global's Mega Moolah is a well-known example. Some progressives are must-drop, guaranteed to pay before a set time or amount.
The trade-off is in the RTP. Part of what the game returns goes into the pot, so the base game usually returns less than a comparable non-jackpot slot, and most players never receive the jackpot share. Games often publish the base RTP and the jackpot contribution separately.
Winning is random. A large pot is not "due" to drop. See our progressive jackpots feature page.