They did that on Dr Who in an old series on Mars.
Two Mummy guards in front of two doors, one always tells the truth, one always lies.
You can ask one guard one question to chose a door.
reddit had itFrom the classic Doctor Who episode "The Pyramids of Mars":
HORUS [OC]: Intruders, you face the twin guardians of Horus. One is programmed to deceive, the other points truly.
(Two mummies with gold detailing have appeared, along with two red buttons on the bottom of the tube.)
HORUS [OC]: The two switches control your fate. Instant freedom or instant death. Before you choose, you can ask one guardian one question. This is the riddle of the Osirans. Which is the guardian of life?
DOCTOR: Which indeed. They're both contra-programmed so that one will always give a false indication. One question. If I were to ask your fellow guardian the question, which switch would he indicate?
(The mummy raises an arm towards the nearest button.)
DOCTOR: I see. So if you're the true guardian, that must be the death switch. And if you're the automatic liar, you'd be trying to mislead me, so that still must be the death switch. Therefore, this has to be the one we want. (The Doctor touches the second button, and the tube and mummies vanish.)
