Every progressive is funded by a small slice of each qualifying stake, set in the game rules. When the jackpot is won, it drops back to a seed amount paid by the operator or the game maker, and the climb starts again. The slice set aside for the pot comes out of what the game would otherwise pay in regular wins, so the everyday prizes on a jackpot slot tend to be smaller than on a similar game without one.
Jackpots are won in one of two ways. Some need a specific combination, such as five jackpot symbols on a line at the maximum stake. Others are triggered at random after any spin, often through a jackpot wheel or a bonus game that picks one of several tiers. Random triggers usually give a larger stake a better chance of starting the jackpot game, a rule the game information states plainly in most titles.
Progressive jackpots differ by how widely they are shared. A standalone progressive grows from the stakes on a single game, a local one is shared by several games in one casino, and a network jackpot collects from the same games across many casinos at once. The wider the pool, the larger and rarer the top prize. The jackpot display usually names its type, and the game rules say which casinos or titles feed it.