Goat Door

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.

How to play

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.

• A live ledger tracks how switching versus staying has actually fared for you this run.
• The advantage of switching grows dramatically as the doors multiply.
• Clear every stage to finish the run for a big bonus.

Controls

• Desktop: click a door to pick, then click Switch or Stay.
• Phone & tablet: tap a door and the Switch/Stay buttons — fully touch-friendly.

Game modes

• Daily: the same seeded ladder for everyone.
• Practice: a fresh randomized run.

Tips & strategy

• Switching wins far more often than instinct says — lean into it, especially at high door counts.
• Watch the ledger: your own results converge on the theoretical odds it shows.

What you'll learn

Goat Door turns a famous counterintuitive probability puzzle into a roguelike, so you experience the surprising answer.

• Skills: probability, conditional probability, the Monty Hall problem
• Best for: roughly grades 8–12 (ages 13+)
• For parents & teachers: the classic puzzle that fools everyone.

About Goat Door

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.

A free, original browser game on PlayPendium — no download, no install. Browse all games →