In the National Puzzlers' League, the phrase The Error That Cannot be Named is used in errata to say that the answer, or part of the answer, appears in the puzzle, without giving away what that answer is. In the Mystery Hunt this technique is used on purpose once in a while.
Puzzles
MIT Mystery Hunt 1997 Elvis, Mediator, Solves Labor Deregulation Crisis!
MIT Mystery Hunt 1999 Tbilisi
MIT Mystery Hunt 2000 An Exercise in Futility
MIT Mystery Hunt 2000 Triple Feature
MIT Mystery Hunt 2004 Quagmire
MIT Mystery Hunt 2006 Do Sa Do
MIT Mystery Hunt 2013 Plead the Fifth (the answers to the clues appear elsewhere in the puzzle)
MIT Mystery Hunt 2014 Operator Test
MIT Mystery Hunt 2016 Crimes Against Cruciverbalism
MIT Mystery Hunt 2020 Golden Wolf
MIT Mystery Hunt 2021 Infinite Corridor Simulator
MIT Mystery Hunt 2023 World's Largest Logic Puzzle
Categories