Can You Solve This Week’s Tricky Riddle?


You approach two identical doors. Each door is guarded by identical men.

One door leads to the City of Truth. The other door leads to the City of Liars.

You do not know which door is which. You’re trying to go to the City of Truth.

To find out which door is which, you can ask one question to one of the guards.

The guard at the door leading to the City of Liars always speaks lies. The guard at the door leading to the City of Truth always speaks the truth.

Which one question do you ask to find the correct door?


Stumped? See the video below for the answer:




  1. Alternatively, you ask one to take you to their city. The truth-teller would take you to the city of truth, on account of being truthful. The liar would also take you to the city of truth, because he’s a liar!

    • HA! THAT IS AN AWESOME WAY TO THINK ABOUT IT! If you’ve watched doctor who, the 4th doctor has to solve the same riddle!

      • I got my solution from watching Yu-Gi-Oh. There’s a triplet of episodes where Yugi and Joey have to solve the same riddle.

  2. Which door will the other guard tell you is the door to the City of Truth. Whatever the answer is, choose the other door.

  3. Video is not as relevant as it might be, as the riddle posed has no ‘survival’ element to it. Plus there are other valid answers; it would be nice to see some of those!

  4. You ask either guard what color your shirt is. If the guard answers correctly you go in that door, if incorrectly go through the other door

  5. This one is easy! You ask any brother the Question if i asked your other brother which door he was guarding what would he say? if the person you ask is a liar he would say the door to lies if it was the truthful brother he would say the door to truth. so if their answer is lies then the door to the person your askings door is the lies and if its truth then its the door to truth.
    Posted without watching the tutorial

  6. Without watching vid or reading comments I know u say, “If I were to ask you if this was the door to city of truth what would you say?”

  7. why? because either, both negative x positive or vice versa =negative or both negative x negative and positive x positive = positive.

  8. I love this as it is used in lybrinth. But it always confuses me. If it were me I would ask something obvious. Because if they get it wrong their the list but if they get it right they are truthful. To me it sounds easier then what is said in the video.

  9. First, you ask the man who always tells the truth, “What will the other guard say if I asked him, ‘Which door is the one to the City of Truth?'” and to the Liar, “What would the man who tells the truth say if I asked him, ‘Which door is the correct one?'” The man who tells the truth will say the incorrect one. The liar will say the incorrect one. So therefore, it is the door that neither man said it was.
    Hope I got this right. I’m confident in riddles.

  10. Ask one of them if pigs fly. If it is the truth teller, he will say no, and you should enter the door. If it is the liar, he will say yes, and enter the opposite door.

    Even though it isn’t the supposedly right answer it works. #thuglife

  11. I think there’s an issue with the question you ask them. You still don’t know which is the liar, and which one is the truthful one. So if both respond the same thing, how do you which one is lying. It’s like asking two suspects if they robbed a bank. If they both say they didn’t, how do you know which one is lying. The only way to figure out which door it is is to ask an extremely obvious question.

  12. i already know – i haven’t watched the video
    i got it from a Mensa book that had a variation of the riddle:
    “If I asked the other man which way to the city of truths, what would he say?”
    Both men would point to the city of lies, so choose the opposite.

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