Game:

King's Quest II (1985)

Category:

Vlog

Duration: 28:59

1,001 views

25

I spend half of the video explaining a simple logic puzzle and still somehow manage to get it wrong in the end. I'll try to explain how I think it's supposed to work here.

The mistake which I think I made in this video is assuming that both lions "know" how to get through the door into the tower. This is because in the original riddle--currently known as "Knights and Knaves" on Wikipedia, but often just called the "door to freedom riddle" or the "two-door riddle"--this is the case: both people whom you can ask a question know the "correct" answer. In the riddle in this video, however, only the lion on the right "knows the way through this door", while the one on the left does not. The lion on the right, who knows the correct way through the door, also happens to be the truth-telling lion, while the lion on the left, who does not know the day through the door, happens to be the lying lion. This being the case, if you were to ask the lion on the left whether he knows the way through the door, he would lie and say "yes." Meanwhile, if you were to ask the lion on the right whether he knows the way through the door, he would truthfully say "yes." Notice that both lions would answer "yes" to the question "Do you know the way through this door?" However, both lions start off by answering a different question, namely: "If I were to ask the OTHER lion if he knew the way through this door, what would he answer?" Again, both lions would answer "yes," and so the truth-telling lion on the right truthfully delivers this information, while the lying lion on the left lies and says that the other lion would say "no." We can thus deduce that the lying lion is on the left and not to be trusted, while the truth-telling lion on the right gives us the correct information.

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