Zendo (game)
Zendo is a game of inductive logic designed by Kory Heath in which one player (the "Master") creates a rule for structures ("koans") to follow, and the other players (the "Students") try to discover it by building and studying various koans which follow or break the rule. The first student to correctly state the rule wins.
The rules were published in 2001 after more than a year of playtests and changes. A boxed set of the game was released by Looney Labs at the 2003 Origins Game Fair but is now out of print. The set contained 60 Icehouse pieces in red, yellow, green, and blue, 60 glass stones and a small deck of cards containing simple rules for beginners. Zendo is also published in Looney Labs' Playing with Pyramids, a book of rules and strategies for a dozen popular games playable with Icehouse pieces. The rules are also conveniently available on Wikipedia.
Zendo can be compared to the card game Eleusis and the chess variant Penultima in which players attempt to discover inductively a secret rule thought of by one or more players (called "God" or "Nature" in Eleusis and "Spectators" in Penultima) who declare plays legal or illegal on the basis of their rules.