On most international cruise lines in 2026, the minimum age to gamble in the ship’s casino is 18 years old. This is a significant distinction from the minimum drinking age on many U.S.-based lines, which is often 21. Major carriers like Royal Caribbean, Norwegian Cruise Line, and Carnival typically allow 18-year-olds to play slots, blackjack, and poker once the ship is in international waters (usually 12 miles from the coast). However, there are notable exceptions: if a cruise is sailing in Alaska, the minimum gambling age is often raised to 21 to comply with state laws. Additionally, for cruises departing from certain international ports where the local gambling age is higher, the ship may adjust its rules accordingly. It is also worth noting that while 18-year-olds can often gamble, they are usually still prohibited from ordering alcoholic beverages in the casino if the ship follows a "21 and over" drinking policy. Always check the "Guest Conduct Policy" for your specific itinerary, as some luxury or family-focused lines may have stricter age requirements for their gaming lounges.