Wow. It picked up while I was off for a bit.
First off, terodil, I wouldn't presume to suggest changing D&D would make it "better." Changing a tool rarely makes it better in every possible way. It's a give and take that will make it better for certain applications than others.
Some people wouldn't like my changes. If I were to do it well, hopefully a good number of people might like them as well. I'm just exploring the effectiveness of the concept.
This is more or less the gist of the concept. We don't put up with this oversimplified mechanics in combat, if we're including rules for these other interactions, why not make those rules more robust as well?
Though I think Kaptain Keen might be right that it may have been intentional by D&D creators to deliberately snub these other forms of play. But I wouldn't accept that as reason to NOT change the system. Rather it would be justication for undoing their snubbing and (hopefully) making the games as inclusive of various styles of play as can be.
I've always favored the notion of having active and passive "defenses" on things similar to this idea of general and specific. I like to assume creatures are constantly "taking 10" on perception checks to notice danger (maybe at -5 if the are at ease and preoccupied) and that they may choose to actively search at any time if they feel they need to do more than rely on peripheral vision. It also can help mitigate metagaming because players don't need to be asked to make perception checks and they won't automatically fail. Even if an enemy they are unaware of is sneaking up on them, they are still considered to be taking 10 at all times (unless sleeping or distracted, like preparing spells) and if they read the scenario and correctly guess that it would be a great place for an ambush, they can still choose to roll the d20 for a chance to notice things their passive perception would miss.
I agree, but I would add that combat rules specify when characters are in combat and not in combat. The real trick to "social combat" would be to rigorously define when it was truly applicable.
I see a sliding scale of social interactions that form groups that behave in certain ways (but can be altered greatly based on context, so for simplicity, let's start with a neutral context: a nonhostile verbal discourse).
On one end, you could have totally amenable conversations with no point of contention. There's no need for rules for this, just use roleplay. On the other end of the spectrum, you have a fanatical opposition (still nonhostile, just aggressively unagreeable like some of the more useless debates on this forum) and so there's not much hope for changing the other person's mind unless you can provide an argument that has meaning to them.
Between these stages, there is a wide range of social interactions where there exists contention of wills, but still openness to dialogue. This is the social battleground. It parallels actual combat in the sense that you can't fight somone who surrenders and does not defend themselves (rather it is pointless to try) and that there are some combats that simply can't be reasonably won (unless you can somehow shift the balance of the tactical advantages).
In short, if the outcome is clear from the start, you don't need to make people roll at all (or maybe the system's single roll check is enough). A social combat system would be rather situational (though to be honest, Combat itself is rather situational and most adventures are constructed to throw PCs right into places of highest statistical chances of finding combat).
I like your other ideas as well, but my time this morning is getting short, so I'll come back to this if I can. There are a few other things I want to touch on first.
Ah, see this is a difference of playstyle, not an inadequacy of the rules.
Using this example, I could say:
Next player: "I roll attack. I rolled a 14."
DM *internally*: ok, that beats 10, which is the standard Luck miss chance, so the attack hits except for modifiers. Monster 34 isn't wearing armor or shields and Dex Mod is 2, so it didn't manage to dodge the attack. But the monster has 3 Nat Armor, so...
DM: "The attack glances off the creature's thick hide."
The Nuances of the combat system give players a lot of information to extrapolate without having to make it all up from scratch. There are actually lines for players to read between.
A diplomacy check doesn't get this kind of help from the rules.