card trick without the trick
Most cards can be distinguished as right-side up or upside-down, right? So just have the first card be the suit of the card given, and encode the number 1-13 via binary using right side up / upside down as 1 / 0. Seems much simpler to me than the way given.
um, no. most cards cannot be distinguished by orientation. any card upside down looks the same as it did right side up, if you're looking at the backs, and more than half the cards are the same when reversed if you're looking at the faces.
Some (real) card tricks actually are based on this principle.
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