This 2D simulator recreates the classic Monty Hall game show puzzle: three doors hide one car and two goats, you pick a door, the host always opens a different door to reveal a goat, and you decide whether to stay with your original pick or switch to the other unopened door. Play by hand to build intuition, or switch to batch mode to run thousands of automatic trials at adjustable speed and watch the live win-rate readout converge to the theoretical 66.7% for always-switching versus 33.3% for always-staying — a vivid demonstration of how the host's guaranteed-goat reveal quietly shifts the odds.