What's in the box?
Read this out to the room
Everyone who opens this code gets the same qubit and the same six answers.
Show the prepared state (spoils the round)
Open one face. You only get one.
What does this tell me?
Which one is it?
Why one shot was never enough
What every face would have told you
How to read the box
Three faces, six answers. Every answer is also one of the six states the box can hold. That is why seeing one does not mean you have found it.
Why one shot is never enough
Measure a state along its own axis and it gives the same answer every time. Measure it along either of the other two and it is a 50/50 coin flip.
So one shot rules out exactly one of the six: the pole opposite what you saw. Five are still possible. Coral does not mean the box holds |+⟩ — every state except |−⟩ can give you coral, and four of them do it half the time.
The way through is repetition. The face the room stops disagreeing on is the axis the qubit is on, and the end it agrees on names the pole.