Perception, in D&D 3.5, is mostly a matter of special senses (darkvision, blindsight, Mindsight, touchsight, Lifesense, tremorsense, blindsense, see invisibility, true seeing, Nemesis, scent, scry...) and their countermeasures, but I agree it's not nearly as structured and accessible as simple melee combat.

D&D 3.5 social skills are clearer and more structured, just very simple and monotonous. I'm not sure a good set of rules covers social interaction to the same level of detail as melee combat ("roll 12 or higher to land this argument for 2d8+4 morale points of damage--they've only got 10 morale points left before you convince them!"), but a simple d20 roll doesn't cut it. I started writing a set of house rules for negotiation processes, with the idea that it's like a trick-taking game where each trick is a contested proposition/argument, but I think it ended up being too complicated for shorter or routine conversations, and too monotonous to really match the melee combat system in depth (also because I used the D&D skill system, which is pretty monotonous).