Granted, it is impossible to prevent anyone from role-playing in any game. You can role-play with Monopoly, if you have a mind to. It is also cheaper, and comes with its own minis.
That said, it depends very much what one means by "role-playing". I would consider role-playing to be taking the role of a fictional character within a fictional game milieu, but I would add the caveat that actual "role-playing" isn't based upon colourful descriptions or pithy one-liners, but rather upon identifying with the fiction.
A ruleset for a role-playing game is, therefore, IMHO, an interface to support identification with the fictional persona and setting to occur. And a ruleset can be more -- or less -- successful at doing so.
IMHO, role-playing occurs when the fictional characters/setting are more important that the rules structure that allows interface. I.e., if a rule gives an outcome that jars the fictional setting, the rule should not be applied. Thus the importance -- and primacy -- of Rule 0.
To the degree that a system causes players to focus on the rules structure, that system is going to inhibit role-playing. Not prevent, mind you -- nothing can do that -- but inhibit.
So we add our first rule: "The less rules intrude on the fiction, the more the game supports role-playing."
And, frankly, you can see the same applied to computer games. The more you have to think about what must be done to manipulate your avatar in the computer game, the less enmeshed you are in the computer game's "world". Were this not true, we would still be typing in command codes, and the Wii wouldn't be as popular as it is.
For that matter, many computer games I have played hide your "game stats" (apart from health) for the purpose of fostering identification with the character rather than the stats.
So, we can add: "The less often you have to break from the fiction in order to check your stats/character sheets, the more the game supports role-playing."
I would also add: "The less often you have to break from the fiction in order to check a game board/grid, the more the game supports role-playing."
And herein we see why Monopoly is not ideal as a role-playing game (strong board focus, rules prevent logical actions within the fictional milieu -- such as not trying to stay in a Boardwalk Hotel when you're cash is running out) and where it shines (Minimum of "stats checking" that interferes with your chosen role -- your only "stats" are the properties you own, what you've built on them, and what cash you have).
Obviously, the more familiar you are with any system, the easier it will be to role-play within that system. It is to be expected, with any system, that rules mastery limits the amount of rules checking and character sheet checking, and thus increases the quality of a game vis-a-vis role-playing. The amount of errata (if used) and new material being pumped into a system (again, if used) tends to erode system mastery, however.
Also, one should note that the three rules given above support another, rather obvious conclusion.
1. "The less rules intrude on the fiction, the more the game supports role-playing."
2. "The less often you have to break from the fiction in order to check your stats/character sheets, the more the game supports role-playing."
3. "The less often you have to break from the fiction in order to check a game board/grid, the more the game supports role-playing."
In any edition of the game, when do the rules intrude the most, character sheets need the most checking, and the game board/grid become most relevant? Why, combat, of course!
So,
4. "The less time you spend in combat -- especially in the same long combat, or engaged in the rules minutia of combat -- the more the game supports role-playing."
All IMHO and IME, of course. YMMV.
RC
