In about half of USA casinos, drinks are free for those actively gaming, in the other half there will be some nominal charge. Either way, you should tip a minimumR$1 and preferablyR$2 for each drink, whether it's alcoholic or not. And then feel free to go higher for great service and customer care.
Tipping at a casino is a personal decision, but it's generally customary to tip around 1-2% of the jackpot to the attendants who assist in the payout.
