Customers gamble by playing slot machines or other games of chance (e.g., craps, roulette, baccarat) and some skill (e.g., blackjack, poker). Games usually have mathematically-determined odds that ensure the house retains a long term advantage over the players. This advantage is called the house edge. In games such as poker where players play against each other, the house takes a commission called the rake. Casinos often give out free items, known as comps to people who are gambling.

Payout is the percentage won by players.

Playing with house money refers to the situation where a winning player is placing bets with money that has been won from the casino.