18 is probably the "somewhat average" line we draw from a legal sense when we decide people are able to make and be responsible for their own decisions. Some pl

18 is probably the "somewhat average" line we draw from a legal sense when we decide people are able to make and be responsible for their own decisions. Some places and for some reasons it's 16, or 21. It's not a perfect method by any means, but it protects for the most part the most vulnerable of our population.