246: Labyrinth Puzzle
Title text: And the whole setup is just a trap to capture escaping logicians. None of the doors actually lead out.
This comic alludes to a famous Knights and Knaves logic puzzle, and specifically to the version featured in the Jim Henson movie Labyrinth, with two doors and two guards. One guard always lies, and the other always tells the truth. One of the doors leads to freedom, and you can only ask one guard one question. The solution to this riddle involves a tricky question indeed, and in the xkcd-version one would risk a stabbing from the third guard. If you want to give the original puzzle a try for yourself, don't read the spoiler in the next paragraph.
Solution: Ask one guard (it doesn't matter which one) which door the other guard would say leads out. The door indicated does not lead out.
- Black Hat: And here we have the labyrinth guards. One always lies, one always tells the truth, and one stabs people who ask tricky questions.