When you purchase the CHEERS! Beverage Program on Carnival Cruise Line, a mandatory service charge is added to the base price at the time of checkout. This means the standard gratuity for the bartenders and servers is technically "pre-paid" or included in the total cost you see on your final invoice. However, it is important to note that this 18% gratuity is applied to the total cost of the package, not per drink. If you are sailing from a US port, you may also see a temporary addition of local sales tax on drinks served while the ship is in territorial waters. While the standard tips are covered, many guests choose to provide an additional small cash tip for exceptional service, though this is entirely at your discretion. The package covers a wide range of alcoholic and non-alcoholic beverages up to a certain price point, ensuring that your "on-board" spending for individual drinks remains at zero as long as you stay within the daily limit.