If you GM like me, you like to provide objectives that players try to reach. You then put a few obstacles in their way, but for the most part they can do whatever they like to try and reach that objective. This is very limiting in social encounters.
Thinking of social encounters in this way tends to limit the kinds of social behaviour that PCs engage in. It causes the characters to interact with NPCs in order to persuade the NPCS to do something specific. However, in real life most people engage in social encounters for a wide variety of reasons.
I have a bit of a background in therapy, and part of my job was teaching social skills. Given that, I am accustomed to dividing social behaviours into categories based on the function those behaviours serve. There are three such functions: achieving objectives, maintaining relationships, and preserving self-respect.
Of course, in a game being told to “maintain your relationship” is just being provided with an objective. I don’t see this as a problem, because it will substantially change the way the scene must be role-played. Imagine the PCs are a rag-tag group of fantasy adventurers, and they rely on the patronage of the local baron. The PCs have a rival group of adventurers that are trying to “steal” the baron’s patronage, and the baron is kind of a boring, snobby guy. If I present this as a problem to my PCs, ways to solve this will probably involve doing something to the rivals. However, as anyone who works in Sales can tell you, business is often about relationships. If the PCs wish to maintain the baron’s patronage, then they must maintain a positive relationship with the baron. This strikes me as plausible, or even realistic, and will result in the PCs engaging with an NPCs like the NPC is actually a person.
Preserving self-respect is used to defend oneself from unfair accusations and treatment. If you are tired of every single dispute devolving into violence in your game, then this is for you. Note that part of preserving self-respect is NOT attacking the other person. The goal is for the PCs to just stick to their own values. Imagine the characterization opportunities in such a scene.
Lets take the above situation with the adventurers, their rivals, and the baron. I’ll add a bit more to it. The rivals accuse the PCs of recklessly starting a big fight in a tavern. This is starting to sound like a D&D game. The PCs probably blew up the whole tavern with a fireball or something. Regardless, now the PCs need to defend their values, their choices, and even their character or personality. Of course, they could just lie. That solves the immediate problem, but doesn’t involve preserving their self-respect. Defending themselves without lying or attacking their accusers will force the players into engaging with this more “correctly.”
In a game with an extensive skill set, this will help make a lot of the more subtle social skills useful. Etiquette, for example, works really well for preserving-self respect and maintaining relationships.
This also relates to player skills (as opposed to skills possessed by the character). It can be used to broaden the social skill portion of roleplaying by including a wider selection of scene types.