Words for the Week, or in this case, Geekspeak 101
These terms were made popular by E. Gary Gygax and the bright boys at TSR (long before the big buyout by Wizards of the Coast in the '90s), the people who brought you the Chainmail and Dungeons & Dragons roleplaying games.
n. Joe (or Jo) Geek's alter-ego in these role playing games.
DM or GM
n. abbrev. "Dungeon Master" or "Game Master" respectively. Non-geeks know these terms under the umbrella word, referee.
The DM or GM is the architect of the virtual world in which the players, through their characters, interact. Assisted by the core rules of his game, he is the final arbiter of what happens to whose character during gameplay.
n. pl. (also refered to as HP) units of structural integrity as applied primarily to (1) life forms and animated constructs, (2) vehicles, (3) buildings.
Animate and inanimate objects are assumed to have a set number of hit points, which vary depending on factors like general health (for the living) and sturdy construction (for the inanimate). Hit points are gained or lost depending on the kind of punishment one puts these objects through. The greater the punishment, the greater the hit point loss. If someone's hit points reach zero, it is the general consensus that that individual is dead.
Big, burly hardened serial rapist-killers generally have more hit points than the average scrawny geek. Bulldozers will have many times more hit points than either of them.
n. Joe (or Jo) Geek, Roleplayer.
1. n. abbrev. Role Playing Game, improvisational theater with dice and paper
2. n. abbrev. rocket propelled grenade