In the US, the legal age to gamble varies by state, but typically you must be 18 or 21 years old. Different types of gambling, such as casinos, lotteries, and online betting, may have different age requirements. It is crucial to check the specific laws in your state before participating in any form of gambling. Underage gambling is illegal and can result in fines or other penalties. Always gamble responsibly and within the legal age limits to avoid any consequences.