Today we're ranking these games in terms of “ House Edge,” which means how The casinos look at these games as “applied mathematics. Take a look at the best and worst picks for online casino games, which differ wildly at their house edge percentages. Every single casino game provides a long term advantage to the house, and this is how they make money. The advantage that's effectively built into every casino game is known as the house edge. This edge means . Online Casino Reviews.