I don't think there are countries who allow minors to play in gambling, because as far as i know, such countries do even have sanctions once they found out. And to think that gambling needs money to make it happen, so how can these kids afford it if they don't have source of income in the first place. And since these kids have immature minds, they should be staying in school to learn more and grow. And parents are big part of it to guide them not to fall for gambling.