This depends on the pokie you are playing. For pokies with progressive jackpots, you might need to place the max bet to qualify for the full jackpot. However, for fixed jackpot slots, you do not need to place any specific bet. The jackpot will be something like 10 000x your bet. So, if you place the minimum bet, you will still win the 10 000x jackpot, but you will get less than if you had a larger bet.