In Illinois, individuals must be at least 21 years old to gamble at casinos, but some forms of gambling are allowed at 18, such as the lottery and horse racing. The legal gambling age for participating in charitable gaming activities is also 18 in Illinois. It is important to verify the age requirements for specific gambling activities in the state to ensure compliance with the law. Gambling underage can result in legal consequences and penalties. Always confirm the age restrictions and regulations before engaging in any form of gambling in Illinois.