The other way to win in the casinos is to play games against other people and not the casino. For example in the poker room, the casino might still take 5% off the table, but if you are more than 5% better than the other players then you will take their money and end up ahead on average

The casino couldn’t care less who wins (someone always does) as they still take 5% but if you are a good player playing against drunken people that lost their money on roulette, blackjack and other losing propositions then you can walk away with their money (- the casino’s fee).

In this case, the skill comes in learning the game and trying not to be the pats