1. The person that controls and facilitates the various elements (including NPC, environment, monsters, etc.) in a role-playing game, such as Dungeons and Dragons (commonly called a "dungeon master").
EX. Pictured above is a goblin game master, and his gibbering chums, playing a home brew game of Lawyers & Lattes. The game master, Kreppler, has just asked Skoll to roll a check to see if he can successfully intimidate the defendant's lawyer in the court bathroom. Luckily, Skoll's player character, Steven Brown, has a high Intimidate skill bonus and will probably succeed on intimidating the honest lawyer he is in intimidating. Kreppler smirks as Skoll rolls a measly 13.
"Just rip of his head!" Ludd shouted from across the table before being struck on the head by the troll to his right.
"Shut up." Kreppler hissed, "And eat you Halfling rinds!" He sneared as he looked over at Skoll, "Dennis Smith doesn't take kindly to your intimidating tactics and just smiles to himself as you try to intimidate him. Zipping up his pants, he leaves the bathroom without washing his hands."
"Nine Hells!" Skoll hissed, "And I gotta shake hands with that bastard."
"That's the luck of the die, Skoll-face." Kreppler sneared.
"I still don't see why he couldn't rip his head off..."Ludd mumbled, to himself, bitterly.