The jackpot is triggered by a specific combination of symbols on the reels. When you pull the lever or push the button, the random number generator generates a mixture of symbols. If the given combination matches the jackpot combination, you win big time.

Predicting a slot machine's payout is not possible, as modern slot machines use random number generators to determine the outcome of each spin. These random number generators ensure that each spin is independent of the previous one, making it impossible to predict the outcome with certainty.