The first time you entered a virtual world, you were probably struck by the avatar on the screen before you. This is the player as pilot, and the avatar as something entirely distinct, little more than a tool or vehicle with which to explore the new space you find yourself in, like a remote-controlled robot rover sending pictures back from the surface of a distant planet.
But as your familiarity with your new environment develops, you soon begin to understand the digital person before you as a character in his or her own right, according to Bartle. Now, the avatar is no longer a puppet, but is a distinct personality, probably a mix of your own character traits and a few you think might be interesting to have or to explore. The character is still someone recognizably separate from yourself, but it's "someone" nonetheless (as a characters in a piece of fiction is "someone"), it's no longer "something."
Most people might assume this is as deep as things go without straying into the territory of mental illness. But there's more, a deeper level of immersion. "The more immersed you are, the closer your game character is to being you," Bartle told me in a recent interview. "By selecting an avatar, you're choosing how others will see you superficially. By playing a character using that avatar, you're experimenting with aspects of your personality. By emphasizing and de-emphasizing facets of the character's personality and your own personality, eventually the two lock together and you have a persona."
At the persona level of immersion, according to Bartle, the virtual world is just another place you might visit, like Sydney or Rome. Your avatar is simply the clothing you wear when you go there. There is no more vehicle, no more separate character. It's just you, in the world.
Of course, Bartle says, many players will protest their avatar carries more weight than just a suit of clothes. If that's the case, "you have more immersion to go yet," Bartle argues. If you still inhabit a character in a virtual world - in other words, if you're roleplaying - you yourself are not really in the world as fully as you could be. "You haven't yet combined character and player into persona," Bartle says. When you and the character are finally unified, "then it is you in there - no metaphor about it."
Perhaps that explains why I compliment myself each time my Rogue puts a nice garotte around some vile Stormwind Warrior's neck: Because it isn't my Rogue in there at all, it's me. And that answers the question of what difference it makes. Bartle puts it nicely: "The point of playing a virtual world is to celebrate and understand who you are."
And here you were thinking the point was to level as fast as possible so you could get your hands on all that awesome loot. Not at all, my friend. This is "a personal journey of self-discovery" we're on, according to Bartle, much like the "hero's journey" Joseph Campbell described in his 1949 book, The Hero with a Thousand Faces. There, Campbell outlines an archetypal "monomyth" in which the hero is sent away from the world he knows to accomplish a task in a world of unknown dangers and challenges. He must pass a series of trials by drawing on aspects of himself he hardly knew he had, or which he's creating on the spot. Finally, he accomplishes the goal of his long quest, and returns home with new knowledge of himself, a person changed by the roles he took on during his adventure.