Winning a progressive jackpot on a slot machine usually requires betting the maximum amount, as many machines only qualify players for the top prize if they meet this bet. If a player wagers less than the maximum, they may still win smaller prizes, but they typically won’t be eligible for the progressive jackpot. Some slot games, however, have different rules, allowing smaller contributions or side bets to access the jackpot, though these are less common. Always checking the machine's rules is crucial, as they vary by game and casino.