Word-Mastermind variant, which I believe was published before its more famous compatriot. One player thinks of a five letter word. The decoder must try to find it in as few guesses as possible. The mechanic for the decoder is that he or she must think of a five letter word themselves, show it to the problem setter, who then allocates different coloured pegs signifying right letter/wrong spot or right letter/right spot. Points are rewarded for the length of guesses needed to discover the word. I guess the one who is first to a pre-set agreed total, wins.