Changing the payout structure on a slot machine during a cruise is a myth and not to be believed. It simply is not that easy to do as they must follow the ICCI rules which are based on Las Vegas and U.K. gambling laws. In Las Vegas the house advantage can be as high as 17% by law, but does not necessarily have to be that high.
That means if you put in $100 you can expect to get back $83 at the least. Some machines are programmed to pay out higher. You need to find these machines.
The best odds in the casino are on the craps table. Bet on the pass or don't pass line and the casino odds are 1.41%. Also, the blackjack table provides good odds for the player if you play perfect blackjack strategy. And rolling the dice or selecting cards cannot be programmed! STAY AWAY FROM SLOTS!!!!!!!!