A fixed jackpot usually has a set prize, while a progressive jackpot can increase as qualifying plays contribute to the prize pool. Some games also have specific conditions that determine when a jackpot can be won, so the headline prize doesn’t tell you everything about how the game works. I think reading the paytable and instructions is a sensible first step, especially if a game has bonus rounds or special symbols. The size of a jackpot can catch people’s attention, but the rules, odds, and overall gameplay are just as important when comparing different options.