Diplomacy . diplomacy is simplified as negotiation, etiquette, getting along, conversation etc. In my experience, a Diplomatic task is any difficult negotiation of various conflicting interests or a long term behavioral strategy. Someone who is diplomatic, is a person who has mastered getting the most Good will, trust, reputation, and credibility out of every effort he puts out.
A diplomatic person knows the costs of "conquering" and "holding" any position of great strategic value. Such a person has drilled into him skills that come naturally when called to turn situations into their favor.
Below I break down the action, but keep in mind in practice these all blend into a skill that encompass and entire lifestyle when truly mastered. Just because the masters of diplomacy make it look easy, doesn't mean it is. Anyone who wants to be more Emotionally intelligent about their life and time with others find Diplomacy a worthwhile long term behavioral strategy, despite their disinclination.
Knowing the interests of all parties involved. "Intelligence gathering" is a sophisticated way of beginning the most fundamental step in any scientific or problem solving method: asking the right question. Before interests begin to answered, a practiced or familiarized mental process of empathizing and asking "what is it for the us/me?".Skills that make this task easier is definitely: psychology or knowledge regarding human behavior and interests, information regarding the condition and status of the other person's affairs (which may need bureaucratic and observational skills), and the appropriate communication language or medium.Finding the optimal and multiple ways of satisfying all parties involved. This skill involves some math and good head for numbers and figures. Even when dealing with currency like favors, political capital and especially time, one needs to be able to give a quick account what they can afford, and what it will cost them.Skills. Finance or Merchantry - the skill with moving and investing cash or other cash-like resources. Math, Accounting, or any way skill that allows the character to deal with large and complex values. And knowledge of various costs (from running a city, marketplace, a guild, an army on the march etc...).Being able to frame the solution and negotiation in a way that all parties are more receptive. Framing is the art of crafting words to mean something else than they would normally. Framing takes advantage of cognitive biases, or Works to prevent cognitive biases from affecting the value assessment of the other party to be detrimental to negotiations.
Skills. Philosophy, Psychology, Literature or Written Composition, empathy, Savoir-faire, Acting or Poker face (Bluffing) etc.Like almost all scientific and problem solving methods, the pattern follows Input > Process > repeat Step 1 and 2 until Success.
How is this useful in the Game?
Well, for starters GMs who work towards being more EI in their game (which smacks of KODT's more role-playing less hacking philosophy paradoy of the old school ideal) who are themselves introverted (like myself) can learn to look at the complexity of a problem instead of glossing over the details and bashing it.
when problems are solved in this way, personal social problems tend to be less intimidating and frustrating because of the empathic and critical thinking skills it encourages.