Bawylie
A very OK person
Very much agree that "Insight" is not the only skill that might be used to determine the NPC is lying.
And also very much agree with this. This is why I always make the dice the medium between the player and the game world. I've played with many cunning linguists who use their great word skills to attempt to bypass the dice rolling part of the game, and even play low-mental-score/skill characters while trying to speak like their characters are highly intelligent. But I've also played with new, young and challenged players who still want to play a smart wizard, a wise monk, a clever rogue or some other sort of high-mental-stat character but these folks just aren't capable of saying the kinds of things their character would.
So the dice as always the middleman between the words the player uses, and the words the PC uses.
But none of that addresses his point. Just because you think his argument is poor doesn't mean it is or even that it's wrong. It's anecdotal but I've seen his argument in action. I've played with DMs who let good player words completely bypass things that less-clever wordsmiths have to make checks for.
I’m not gonna debate action resolution in this thread but the idea that more eloquent people have an unfair advantage is bunk. We’re not looking for perfect description or dissertations. We’re looking for an articulated objective and a reasonable approach to achieve that objective. No more complicated than “I attack with my sword.”
I ran a game for 8 years for players with various disabilities. One player was a severely autistic kid, one was a mentally retarded adult. Neither of them ever had a problem saying what they wanted their characters to do nor how they tried to do it. I don’t think anyone with social anxiety would be in a worse position than either of those two. They weren’t worse players than the two with physical-only disabilities.