The museum is closing, but Curator Ada has one last challenge for Puz. Three doors, one hidden badge — and a choice that is trickier than it looks.
One last mystery
Puz pauses beside the dinosaur skeleton. Across the gallery stand three closed purple doors. Ada smiles and lifts her keys.
Curator Ada“One door hides a golden detective badge. The other two rooms are empty. The badge could be behind any door, with the same chance.”
Puz studies the doors. There are no clues on the outside — just three brass handles waiting to be turned.
Puz makes a choice
Puz“I’ll choose Door 1!”
Ada nods, but leaves the door closed. Puz’s first choice is made. The badge is still hidden.
An empty room. A new decision.
Ada knows exactly where the badge is. She walks past Puz’s chosen door and opens Door 3. Inside is an empty display stand.
Curator Ada“I always open an empty door you didn’t choose. If two empty doors are available, I choose between them equally at random. And I always give you the chance to switch.”
Only Door 1 and Door 2 remain closed. Ada turns to Puz.
Curator Ada“Will you keep Door 1, or switch to Door 2?”
Puz tilts their detective hat. It looks like a choice between two doors… but is each choice equally good?
The curator’s promiseA fair mystery, every time.4 rules
- An equal start
Before each round, the badge is equally likely to be behind any door.
- An empty door, always
Ada knows where the badge is and always opens an unchosen empty door.
- No secret signals
When two empty doors are available, Ada chooses between them equally at random.
- A chance to change your mind
Ada always offers you the chance to switch.