You can be in a casino at 18 in some countries but not all, as the legal age varies by location. It’s crucial to verify the specific age restrictions in the region you plan to visit. While some places allow individuals 18 and over to enter a casino, others may require you to be 21 or older. Always check the rules and regulations of the casino you intend to visit beforehand to avoid any issues. Remember to carry valid identification to prove your age if needed.