I was reading http://penny-arcade.com/2012/12/28/playing-roles and they raise a very valid point right at the end of the post about what players know about what is possible in a game. We learn by playing our roleplaying games if I do action x, they will get result y (all rolling non withstanding). A new player doesn't have this sense. On one hand this can be good as they will try things that the group has deemed "bad options" and surprise everyone when they work. On the other had they will try "bad options" and find out why no one uses them. Their sense of the physics of the system and the world are incomplete. The difficult question that faces every RPG out there is how to let the new players know they physics. This becomes more of an issue for smaller RPG writing outfits as someone may pick up your game without ever having played it. For the larger RPGs most people are brought to it by DMs who have played before and know the rules. Overall I believe RPGs could do more like the recent Edge of the Empire game to be accessible to new players. Yes, people inviting others to play grows the hobby but you can't ignore the first generation players either.