Two doors.
One leads to freedom, one to doom.
Two guards — one always lies, one always tells the truth.
You get one question.
What do you ask?

Question

Accepted Answer

Ask either guard: “Which door would the OTHER guard say leads to freedom?” — then pick the opposite. — Whichever guard you ask, the answer routes through one liar. Truth-teller relays the lie. Liar lies about the truth. Both arrows point to the wrong door — so flip it. Beautiful, isn’t it.

Two doors. One leads to freedom, one to doom. Two guards — one always lies, one always tells the truth. You get one question. What do you ask?