You have to be at least 18 years old to go to a casino in most countries. Some places require you to be 21 before entering a casino. Age restrictions are in place to prevent minors from participating in gambling activities. It is essential to carry a valid form of identification to prove your age at the casino entrance. Casinos may deny entry if you do not meet the minimum age requirement. Always check the legal age for gambling in the specific location you plan to visit.