So are any two PCs.
<snip>
There isn't anything inherently different between a PC and an NPC.
Is there an inherent difference in the fiction? Typically not.
Is there an inherent difference from the metagame point of view? Absolutely yes, in the way I play the game. The PCs are protagonists. The NPCs are not.
In fact, it's not uncommon for characters to transition between different players or player and DM, particularly when one is "retired". The character's statistics aren't redefined when this happens, because they are a property of the character, not the player.
The non-change of statistics, when this sort of change in metagame role takes place, is a function of system. In 4e the default assumption is that there
is a change of statistics (see DMG2 for the discussion of companion characters).
The rationale is that a character handled by a player can tolerate a more complex action resolution process than one handled by a GM. And also should be putting different demands on pacing. Hence, in 4e, a PC has fewer hit points but more mechanically complex options for hit point recovery - which also feed into the pacing of combat - whereas an NPC or monster of the same level typically has more hit points but few or no methods for recovering those hit points: simpler action resolution, more steady pacing.
This is just one way in which 4e trades on the abstract nature of D&D's mechanics: "luck and divine favour" can be built and resolved either as more hit points (NPCs) or as more healing surges with access to mechanics to take advantage of them (PCs).
It is certainly a valid choice for a DM to say that because a nonplayer character's role in the story is different, a different mechanical structure may be used to define the character (perhaps simplifying or altering the mechanics to produce the blacksmith of his dreams), but that's not a choice the designers should really be forcing on everyone and all their characters.
The system has to take a stand here. And the stand will affect play - the notion of playstyle-neutral mechanics is, in my view, an illusion.
It may be possible for the system to present multiple options (though this may not be trivial), or to have a single option that supports multiple playstyles (4e certainly supports multiple playstyles, judging from the different approaches of various 4e players who post on this forum), but it strike me as impossible for it to support any playstyle. And in my view the history and theory of game design give strong reason to think that it is particularly hard to accomodate strong simulationist preferences while also catering to other playstyles. Well-known examples are complaints about minutiae getting in the way of scene-framing and resolution (narrativist complaints about process simulationinst mechanics) or complaints about the game breaking down when high level fighters are still mortal, while high level wizards are godlike (gamist complaints about high concept simulationist mechanics).
D&Dnext seems to be hoping to square this circle by punting a lot of responsibility onto an expctation that the GM use force to control the game. This is very much the 2nd ed AD&D approach, as well as - I think - one reasonably common approach to 3E play. It is not, in itself, playstyle neutral, given that some playstyles (eg narrativism, just to push my own barrow) depend heavily upon limiting, regulating and channelling GM force in certain well-defined ways.
I'm guessing that caused some problems.
Not really. What sort of problems would you have in mind?
Really? You don't think in terms of every D&D character having six ability scores?
This is pretty central to
building a PC. It's not a big part of the fiction, though, nor of all action resolution. I GM plenty of NPCs who lack those scores. I GMed a lot of AD&D without worrying about what the STR of a giraffe or the CON of a troll was.
certain people expect that everyone will share in that system together (I think most players do and probably most DMs as well; in any case, several people in this thread do and that underlying assumption wasn't getting across).
What's with this readiness to generalise without evidence. The only RPG I'm aware of that tries to put NPCs, monsters and PCs all on the same build mechanics is 3E D&D (maybe points-buy systems, looked at in a certain way, also fit this description - but almost certainly the points totals and other constraints on points expenditure will be different). I therefore simply don't think it's true that most players and GMs expect this in an RPG.
Listening to Paizo talk about
their upcoming mythic supplement, I was struck by how they mentioned mythic creatures and characters getting advantages in hit points and the action economy without changing their base number too much.
Hmm, I can think of another system that does that. Oh yes, 4e.
On some level, it was rather like parts of this discussion, but the mythic thing is very different in that it's a complete integrated system
I'm not sure what that means, or how it sets up a contrast with 4e.
works within D&D's advancement by level model
Can you elaborate - if the base numbers don't change, but the hit points do, how is the creature advancing in level?
means something in the game world
Being a dragon, or a hydra, or a beholder, or a golem, etc, all mean something in the gameworld in 4e. I don't understand the basis for asserting otherwise.
Boss monsters, in 4E, have a special mechanic (extra actions) which is a rather unique mechanic. In particular, that mechanic does not follow from the regular rules.
I'm not sure what you're talking about here. There is no general "extra action" or "boss monster" mechanic in 4e.
