Lie Detector
Lie Detector
This interactive demonstration simulates the “Lie Detector” card trick. In this effect, a performer can seemingly detect when a spectator is lying about the color of a card. The trick uses the Gilbreath Principle, which ensures that when cards are dealt into two piles from a specially arranged deck, the cards in corresponding positions will have opposite colors.
I'll call out the color of each card. Your job is to guess if I'm telling the truth or lying.
Click either the word "Correct" or the checkmark ✓ if you think I'm telling the truth.
Click either the word "Wrong" or the cross ✗ if you think I'm lying.
We'll do this for 10 cards, and then move to Phase 2.
Now it's your turn! Look at each card and decide whether to tell the truth or lie about its color.
Click the RED or BLACK button to indicate what you claim the card's color is.
Our lie detector will determine if you're being truthful based on the sequence recorded in Phase 1!
The trick above demonstrates the Gilbreath Principle, which is a mathematical property that allows for seemingly impossible predictions. In the real version of this trick, the performer secretly knows the colors of the cards in the spectator’s pile because they are the opposite of the colors in their own pile. This creates the illusion of mind-reading or lie detection.