Age is age but maturity is what really matters. This is where parents come into play. They can determine how they want to raise their child and wether their child is mature enough for a thing. You could have a kid that's mature, and knows the fine line between a game and real life. And vice versa, you could have an adult that simply doesn't understand the difference between a game and real life (which sadly there are). And the whole "violent games make kids violent" thing, I still don't believe it. It can give kids bad thoughts and ideas but like my last statement, that's where parents come in. Games such as guitar hero, Fifa, all those games, they don't inspire you to become a rock star or soccer player, they might make you think of it, but not to the point where you would go out and do it. It's more of a simulator in a sense.