instead of limiting exposure, why not educate them about it? I mean, educating them about gambling and the risks and what it can do to people, is one of the best ways to let them know that gambling can be dangerous and there can be grave consequences when it is abused.  I have been mentioning it a lot on this forum whenever a topic like this pops up that "gambling awareness" should be added as a curriculum in schools or at least a subject about addiction in general.