Choose a door, the host throws open the losing ones, and now the real decision begins: switch or stay, and feel the odds shift as the doors multiply.
This is a roguelike spin on the classic switch-or-stay probability puzzle. Pick a door hiding the prize; the host always opens losing doors (never yours, never the prize). Then decide to switch to the remaining door or stay. Win to climb the ladder as the door count grows from 3 toward 100; one wrong door ends the run.
Goat Door turns a famous counterintuitive probability puzzle into a roguelike, so you experience the surprising answer.
Switch or stay after the host opens a losing door is the Monty Hall problem, named for the host of Let's Make a Deal. Steve Selvin posed it in a 1975 letter to The American Statistician; it became notorious in 1990, when Marilyn vos Savant answered it correctly in her Parade column and was contradicted by a great many people who were wrong.
The original framing is the roguelike run, which repeats the decision many times rather than once.
Repetition is the best possible answer to this puzzle, because the correct play — always switch, winning two times in three — is famously unconvincing as an argument and completely convincing as a tally. The condition that makes it work is that the host knows where the prize is and never opens it.
Goat Door turns a famous counterintuitive probability puzzle into a climbing roguelike so you experience the odds rather than just hearing them. It's an original free browser game built for PlayPendium.