From the Gamer’s File: The Invisible Maze Trap

Imagine, if you would, your brave party of adventurers enters a one hundred foot by one hundred foot square room. It appears to be empty. As your party looks across the empty space, a door on the far side opens and a minotaur in plate mail (because if you’re going to use a minotaur to intimidate a party, you might as well put him in plate mail ) walks through. While you watch in fear, the minotaur takes a step forward and taps his axe on the floor in front of him. Immediately, a ten foot by...