Also known as the DM, the Dungeon master is the one man/woman who comands the entire universe of a Dungeons and Dragons
campain. They set out all the interactions and what-not that that the Players experiance. All NPC
s and monsters
and even the gods of the world, are all under the comand of the mighty DM. The only thing not under the control, and incidentaly what mainly makes D&D what it is, are the dice. Lady luck plays her hand on every roll of those hallowed shapes, though there is still rule 0, which alows for the DM to change any rule held in the books at any time. Though nobody plays with people who are like that, they always get shunned back into their closets if they atempt to "play god" and make the Player's lives a living hell. After all, the whole point of the DM is to make the players have fun and get togeather, rather than sit at home and play on the computer all day.
I saw a realy good episode of "Dexter's lab" where Dexter was a horrable, death-dealing Dungeon Master, but Deedee came and saved the day with her feespirit gameplay.