I think this is navel gazing, but in the interests of entertainment:
RPG Theory Glossary
The Letter A:
Abashed: A high falutin' word meant to describe certain inherent tensions in certain pretentious modes of play. ("I am a dark lord of the night, richard, and stop getting Cheetos gunk on my books!")
Noteable here because of the suggestion that the GM just Rule 0 any problems in the system.
Actor Stance: A confusion whereby someone assumes that in-character means saying "Aye, m'lord. I am Vengurik, mighty druid of thee woodlands." instead of, oO(Hmmm, I wonder what I would do here?). Also: the idea that player knowledge is different from character knowledge and if you take an actor stance, you are acting only from the latter.
Assumption Clash: "I shoot you, you die." "Do Not!" "Do Too!" "Do Not!" "Do Too!" Also: Any campaign which falls victim to "Only humans and dwarves guys. This is serious fantasy role-playing, anything else is breaking my finely crafted setting."
Caused by the confusion over where the f&*k one happens to be. There are dice in front of you for playing a game. Rational Science! It sounds like you're trying to read me a novel of your bad fan fiction, frank. Jeeze. Seriously.
Also.2: Used by rule lawyers to annoy the s&*t out of you. "But if we do that, I won't get to be in every fight!" "That's the intent of the rule, man."
Author Stance: Complicated, because it involves things like, "Jeff never shows up, so maaaaaaaybe he shouldn't be the king's heir." This should be avoided, even in narrative style games, because they are games.
Tommrrow? THE LETTER B.
What else would it be?