eyebeams said:
Unfortunately, this leaves out people are are strictly interested in the character as a playing piece premise for problem solving. If we stretch "assume" to accept this then we include the noise of non-RPG activities, like Talisman, V:TES and Monopoly.
Well, it was just a beginning

The
goal of the player isn't what the definition of a roleplaying game should be - what roleplaying games
are should be the definition. Regardless of intent, if the player is not actively assuming a role, it's not roleplaying. If it's not for entertainment, it's not a game.
That does, in order to make sure that we filter out noise, require some more definitions:
A
role is a predefined framework - a container, if you will - that dictates limitations to the player's actions in the game. In most roleplaying games, this is the character - which has stats, skills, spells, whatever that determine what the character is capable of. Most roleplaying games assume behavioral limitations of some kind - alignment, traits, perks, flaws, virtues - but we may get to those here in a bit. Those limitations normally directly affect the choices the player can make - for example, in a game where wizards are constrained to not be proficient with melee weapons, the
role of "wizard" can be assumed to not include being a swordsman. A person trying to play a wizard as a swordsman is not fulfilling the role of wizard, the same way as the father who spends all of his money on gambling and leaves nothing for food for the children is not fulfilling the role of "parent".
I think the question of whether a game character or a real life persona grants more control is unanswerable.
I'm hinging this on the fact the roles are created, by the players, the GM, or the game designers with entertainment value in mind. Social roles, such as "parent" or "employee" have been handed down to us. The question of whether or not these social roles were created is best left unanswered - it's sufficient enough to make the distinction between the roles that we assume on a daily basis and those that we create for play for the purposes of identifying "roleplaying".
Again, there are questions about the motive and intention that are too subjective to resolve. We can think of flawed commonsense objections, but not very strict ones.
Like I pointed out, motive or intention are not completely relevant to what a roleplaying game
is. Regardless of why I play or how I play, the question that arises out of the foundation that I laid out is what
isn't a roleplaying game, and why? In all games, we assume roles - it's the point of playing a game, really. What makes the difference between Talisman and a traditional rpg like D&D in weighing whether one is a roleplaying game or not?
My answer would probably have to be detachment. In a traditional boardgame, there is a large amount of detachment from the playing piece, either intentional or unintentional. You as the player may have a stake in winning the game through the conduit of the playing piece, but you seldom see the piece as having goals and emotions of its own. In a roleplaying game, that is one of the purposes - regardless if the player's intention is the exploration of an internal landscape, telling a good story, or solving puzzles - protraying the the goals and responses of the character are essential to all of them.
Just a brief aside on the game aspect: I believe that agreed upon rules are essential for a roleplaying game. They do not have to facilitate resolving conflict, and they do not have to set in stone. They just need to be mutually agreed upon by all of the players. Games have be rules. The key here is that, much like why we assume roles in rpgs, the rules are followed
voluntarily. I don't follow the rules of being an employee completely voluntarily - I do so because I need a job, and not doing so will deprive me of income. In a game, I can choose which rules to follow or not follow, as long as there is consensus with the players. In computer games, I can likewise choose to not follow the rules - these are called
cheats.
So I could revise my premise and say:
A roleplaying game is a game with a distinct set of rules that each of the players have agreed to follow beforehand, where the players assume created roles for the purpose of portraying the responses of a fictional persona for entertainment.
The biggest problem I can see is this still might be stretched to include V:TeS, and might leave the question unanswered: "If I'm playing Brothers in Arms: Earned in Blood, and I feel remorse for poor Private Marsh because the stupid AI keeps putting him in front of the oil drums, having I created attachment and am I roleplaying?"