Well, the one concept that's really never been done in D&D is the non-magical class whose primary focus is the Interaction pillar. The "Talker" or "Face" class. The other two pillars have classes mainly focused on them-- the Combat pillar has Fighter, Barbarian, Monk etc... and the Exploration pillar has the Rogue, Ranger etc... but the Interaction pillar? The classes who have dabbled in that have always been magical in nature-- the Bard, the Paladin. The closest they've gotten non-magically is the Rogue assuming you build it specifically in that way, away from the prototypical thievery-esque Exploration mechanics.
Well, the one concept that's really never been done in D&D is the non-magical class whose primary focus is the Interaction pillar. The "Talker" or "Face" class.
Personally Defcon 1, I've found that the "interaction" skills tend to be the death of roleplaying at the table.
As long as this thinking holds, though, Charisma becomes a dump stat for most of the party. This is a habit that should be broken. Anything that actively penalizes, in a meaningful way, a character with any ability at less than 10 is going to be the better for it.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.