I don't know; this guy got heavy support in the other thread:Suejak, the LARPing thing is complicated. I'm not going into the whole what is an RPG thing, but I will go into one issue.
That issue is gameplay vs realism in CRPGs, particularly in relation to 'immersion'. I don't mean the sort of immersion that comes from a narrative, setting or reactive world, key components in a good storyfag (or any) CRPG.
I'm referring to the sort of immersion that comes from continually enhancing graphics and coupling that with more and more physics based gameplay elements, basically pushing the gameplay towards a simulation. This type of immersion I believe encourages gameplay elements relating to simulation, the dress up, the romance and sex mods, etc.
Remembering the roots of many CRPGs in P&P, we have an alternate style of gameplay. Less simulation and more 'game', gameplay elements from table top games, etc. Because in this model turn based combat, can be argued to be immersive in the sense it is entertaining, realism/simulation does not factor in. I think this allows a more tactical approach, and reduces the amount of reactive gameplay found in games closer to simulation (aka modern immersive elements).
There is a definite grey area here but the anti-LARPing stance is about getting more 'game' in my games, and cutting back on reflex/simulation based elements.
LARPing is simply pretending, where as most of us play RPGs because they are simulations, that is, the very opposite of pretending. This isn't exactly rocket science here.
So it seems cool new-age Codexers define an ACCEPTABLE roleplaying experience as a "simulation". LARPing, instead, is simply "pretending". I'll admit that it's not a terribly well-thought-out or well-made point, but basically the idea seems to be that unless "roleplaying" directly earns you experience points or loot, then it's LARPing and stupid.
Basically, I think the difference between modern Codexians and classic Codexians is that the latter were okay with imposing their own rules on a game for the sake of the added challenge and flavour. You'd play through Diablo 2 as a fire mage. You'd play through Fallout without using drugs. You'd play through Arcanum with an idiot character. These things "don't directly affect gameplay" in the sense that they are artificial disadvantages for their own sake, but they're fun. Freedom was a big thing. Now freedom seems secondary to a PUNISHING designer dungeon of doom, a la Dark Souls or some other console ARPG claptrap. I had to explain the concept of emergent gameplay in another thread, ffs.
So yeah, these days everybody talks like we need the game DESIGNERS to keep us from saving during dungeons and shit like that, so our magic system will be balanced and we'll have a thrilling action-packed experience. Fuck that. Just don't rest so fucking much and Vancian is a fun system, you goddamn monkeys.
Anyway, you and I seem to see people defining LARP differently. Not a huge surprise. I don't think it means anything in particular anymore.
I actually think you and Lyric Suite agree, the examples you gave actually affect the gameplay, and in a reactive world like Arcanum the narrative is affected by your low intelligence character. If Arcanum didn't react to your dumb character, but you were just running around doing things you considered dumb because you were a dumb character (i.e. go to a store with no gold and sell something worth 1000 gold for next to nothing 'because your dumb'), we begin to see the distinction.
Edit; Also my post was more of a tangent on the sort of gameplay i think encourages/is conducive to LARPing, not really a definition.