Should an 11 year old play rated M games with blood and gore

Well, in most areas a person must be 17 to buy an M rated game. However, this is not the age needed to play the game it all depends on the child's maturity. If you think that the child can play the game without becoming obsessed with it, then they are ready. If they appear to be obsessive over the game then be sure to take it away from them.