Three players — Alice, Bob, and you — each receive a question and must answer without communicating. The rules are set up so that the best classical team strategy wins at most 75% of the rounds. Sharing three entangled qubits in a GHZ state, your team wins every single round.

This is not a trick and not statistics: it’s a game-shaped version of the experiments that ruled out “hidden variables” as an explanation of quantum mechanics. The notebook walks you through playing the game, building the GHZ state with a few gates, and checking that the quantum strategy really is unbeatable.