At a very base level - role playing games are about creating a imaginative space where the player assumes the role of a character or avatar. Dice or no dice. Computer game or not. Miniatures or no miniatures. Gamemaster (DM) or not - the one thing all RPGs have in common is that each player assumes this role, and seeks to "win" or survive the game but there's often no clear or uniformly agreed "winning" scenario. We can define what "winning" means exactly later [1,2].
When you step back and think about it this way - all sorts of games might be considered role playing games beyond the stock pen and paper dice games like Dungeons & Dragons or Savage Worlds. This is probably obvious to most of you, but... indulge me for a minute. Obvious first steps away from the table include live-action role playing games and murder mystery party games (as examples). You will probably also include computer based RPGs such as MMORPGS like Warcraft or single player games like Final Fantasy. Or perhaps even Modern Warfare 2.
But... by extension (and going in a different direction), you might soon find yourself wondering if social media games are RPGs. Games like Mafia Wars and Farmville?
Players in these games definately assume the role of a character or avatar. There's certainly lots of social interaction too. There's also elements of chance (dice) and aspects of improving your avatar over time (leveling). Can you win? Well, perhaps - but I would venture a guess that most of the players of these games don't consider them "winable".
So on the surface, these games might be considered role playing games too. What then do I mean by the Shared Fence?
It may be simply an issue of vocabulary, but to me it seems that social media games are NOT role playing games. There's something fundamentally different about RPGs and social media games that lies in the names themselves.
"Role" implies a singular frame of mind. It starts with YOU and you alone. Everything else comes second. A RPG is about each player first, and their social interaction second. RPGs place a very high value or priority on the individual player experience. Whether you play RPGs face to face or online with a group, or play solo on your PS3 - it's all about you and your role and you having fun playing that role. The fun of the group, while still important, is nonetheless secondary to the fun of the individual.
"Social" implies a group mentality. Social media games (SMGs) place a priority on the GROUP, and how the group interacts - either antagonistcally, cooperatively, or both. The form of interaction doesn't matter. Niether does who exactly is playing. The game itself exists in the absence of the individual, it supercedes the importance of the individual. The goal or point of a social media game it to promote group connectivity and nothing else. If you have have fun playing them - great! but that's a secondary goal of the game itself.
So herein lies the Shared Fence. RPGs and SMGs share much in common, but they also have a fundamental difference in the priorities players instinctively have while playing them. "Role" vs. "Group". The fence that they share though is tied up in this very difference too, since niether game could be what it is without both of these. I am perhaps being a bit muddled or vague here - so I'll say it a different way:
What is a roleplaying game without the player character or avatar?
What is a social media game without the group interaction?I'm not sure - both answers might be "a strategy game". But that's not the point . The point is that social games and RPGs are evolving as we change with the way we interact with each other. I think we are finding that most people like being (overly) connected to others, to categorize their group connections to with them, and to have fun through those connections. The group network - not the avatar fantasy - is what is engaging people more so than ever. That's the draw for games these days regardless of what game you consider .
So, this suggests another question: are SMGs the next great RPGs for the next decade?
Or perhaps something more interesting to consider: How might the (pen and paper) RPG industry step out of the creative silo that it is stuck in?
What might a RPG/SMG crossover game look like? How might be play a real RPG that is a real take anywhere, iPhone/SmartPhone, facebooking, tweeting, table top, dice rolling, avatar playing, social networking, play anywhere RPG that coos and woos to my 2010 tech'phile heart? What would such a game look like?
I'm definitely way way out of my comfort zone on this post - so I'll refer you to an excellent post over at MobUnited.com for more thoughts about that ("Next Gen RPGs"). Or you could leave a comment here and we could chat it up...
Or am I just completely off base and maybe should just head back to my cave?
 I'm stealing the "footnote while blogging" idea from Rob Donoghue (rdonoghue.blogspot.com) - whose blog I'm a recent convert of - becuase it jives with my academic roots.
 Winning in an RPG is generally up to each player. All players, IMHO, play to win - its just that each player has their own goals they would consider winning. It might mean just having fun for one, or defeating the BBEG at the end of the current adventure, surviving the night, or becoming the overlord of Sardonia. Failure might mean getting mad at the other players, being defeated or killed in game, loosing your immersion, etc. It all depends on what you expect to get out of the game.
 You're a mobster. or You're a Farmer. You're a thrall of Facebook... Meh...
 Not today at least. It's a rhetorical question.
 This also brings to mind something that might be worth exploring later: why are PnP RPGs unpopular (relatively speaking) nowadays compared to other gaming mediums? That's a complex question with probably a more complex answer - but... D&D might be less popular than it used to be, but it is still the most popular table top RPG out - so perhaps the problem is not that the industry needs new games; but the industry needs a new medium.