Melanie Shao '24

The Three Gods Riddle

The Hardest Logic Puzzle Ever, also called the Three Gods riddle, is created by an American philosopher and logician George Boolos. It states: Three gods A, B, and C are called, in no particular order, True, False, and Random. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a completely random matter.

 

The problem solver needs to determine the identities of A, B, and C by asking three yes-no questions; each question must be put to exactly one god. The gods understand English, but will answer all questions in their own language, in which the words for yes and no are da and ja, in some order. The problem solver does not know which word means which.

 

The key of the solution is loading each yes or no question with a hypothetical condition, and ask whether the question is true or false. For example, if I asked you “...”, would you say ja? By including the variable phrases in the question, we do not need to know exactly what da and ja mean. Moreover, it would be more helpful if one first determines the identity of True or False, and finds Random through elimination, since he gives out random and unreliable answers.