Here's my idea, or more specifically, the genesis of my idea:  while driving in to work today, I was giving some thought to a couple of potential designs, and found myself wishing that somewhere there was a list of "traditional GM duties".

So, let's do that.  Make a freaking checklist -- not in the sense that "you need to have all of these things" (although maybe you do?), but as a good jumping off point, an aide memoire, and a thought provoker.  And if that's successful, we could look at doing it for other components (such as traditional Player duties).

Who wants to put some tools in the toolbox?

E-mailing the group and getting the schedules figured out.

Proposing game ideas.

Leading character generation.

Mediating character conflicts via the game's rules.

Adding new material to the SIS (all games start here)
- choosing, creating, and customizing setting
- creating character creation guidelines
- approving characters
- creating NPCs, challenges, sets, etc -- 'writing the adventure'
- in-game creation of details, obstacles, and challenges

Adjudicating player input
- assigning difficulty numbers / targets / thresholds / whatever
- determining margin of success/failure
- rolling dice (or whatever) for NPCs
- judging feasibility and desirability of player actions and player statements
- narrating player character results

Keeping track of lots and lots (and lots) of imaginary details, many of which have not been revealed to the players or otherwise introduced into the SIS

Determining "Butterfly Effects" of player actions -- consequences that are not immediately foreseeable (brothers intent on avenging the mook the PCs killed storming the citadel)

Making sure that everyone is involved / gets screen time
- engaging players
- engaging characters (not the same thing)

Pacing, or "keeping it interesting"

Dealing with player complaints and dissatisfaction

Choosing the game system
- selecting and creating house rules

Disbursing Experience Points
- approving XP spends

Often, scheduling players and arranging for game space

Outside of social issues and game-specific concerns, I think that technically, there are only three things a GM does:

• Controls Scene Framing
• Controls/creates aspects of the environment
• Controls/creates NPCs

The three things above, though, allows the GM to introduce events into play, most notably conflicts. This fact has a couple of significant implications on play:

• Introducing events into of play means the GM can heavily influence, if not control, Pacing.
• This poises the GM to best antagonize the characters.

The second thing, antongonizing the characters, needs to be pointed out, as its the big "thing" that the GM "does".