> I'm not sure how things like betting on horse races works, though.
You need to be 18 in most of the states where it's legal, 21 in a handful and 19 in Alabama. I've never seen anyone carding at a racetrack, but then most of the people at a racetrack are 40+
And it doesn't, but it can be slightly harder for a 16-17 year old to get a fake ID without alerting their parents.