The question of knowing my son has come up a lot. (As I have posted this in the lounge as well). Unfortunately IMHO this is not the problem.
I know my son very well. He is articulate, a good reader, enjoys playing with his friends, not a sports fan (/cry), wants to be a pilot one day (well at least this month

), plays with Lego, is only just discovering girls, is head strong, does well at math but needs to work on his hand writing, wants to do the things Dad does, we go camping and 4 wheel driving together, etc., etc.
My problem here (and this could be used as part of the pro - R18 rating argument) is that I can not trust the ratings on the games.
My son's maturity is what I would consider on par for his age. He is starting to "grasp" adult concepts, but because he still thinks like a kids, he misunderstands the meaning or implication that an adult would "get" right off the bat.
Like many of you I played, was was then touted, violent video games and I too believe they have done me no "harm"
I played contact sport, I come from a broken home and I grew up in a schooling system that could be considered "survival of the fittest" due to the fights we got into as Darwin was rebuilding from cyclone Tracy and with every new school built the "who was toughest" pecking order needed to be worked out ... the hard way
All these things added to who I am and in and many ways made me strong enough to deal with challenges later in life.
My son is growing up in a world where "standing up for yourself" is considered anti-social behaviour. If I was picked on in the school yard I had two choices, let it happen or stand up to the bully. If he is picked on he has to tell a teacher, fill out an incident report, attend a meeting session with the bully, seek counselling, etc., etc.
Now I am not advocating bashings in the school yard, but this political correctness crap does not prepare our children for the "real world".
In my son's world, there is no respect for authority any more. There is no "clear" meaning of justice or social order, there is no clear understanding of what it means to be a "Man"! (I am referring to societies views here, not what I try to instil in my boy ... which clash at times

)
So I am a lone voice of guidance vs a world of political correctness gone mad IMHO.
I try to teach my boy to stand up for himself, defend those that are being harassed, use honour and common-sense as a guide, treat women with respect, judge a person by their deeds not their ethnicity or social standing, etc.
But I feel that I am fighting an up hill battle against social views out of wack with reality and pop culture that sends out very different messages then when I was his age.
Yes I played violent video games, but the graphics, sounds, language and concepts of those games are worlds away from what is available today.
The rating systems have no consistency. One game gets an M rating because a character uses foul language or a "boob" is shown, while another gets an M rating because a character decapitates another character in fully gory detail and mounts it to his car bonnet, or because a character can pay for sex with a hooker and then kill her!
While I have a fairly good idea what each game "contains", it is not uncommon for me to play a game that throws in a surprise that makes me go "Holy crap, I hope my son never sees that!"
I don't (and I am sure 99% of parents don't) have to time to play every game through to every possible ending to see if it is ok for my child. Couple that with my lack of faith in our rating systems and you start to see the moral dilemma I face every time my son wants to play a new game.
Now there are other factors my son will face playing games that I never did as a kid ... online play. The amount of "crap" or dangerous talk on these game servers is frightening. So even if the game is ok, I am still concerned about online play due to who he might have to listen to.
I am very concerned that my guidance can be lost in a world that no longer holds justice, truth and decency as values, has a pop culture that try's to "one up" the last product by making it more violent and more vulgar and teaches our kids that authority, loyalty and "being a man" are less important than being part of the social herd.