This 1964 logic game has a mechanic similar to the later Mastermind, but is played with cards and words. There is a deck of 26 Blackout cards, each with a six-letter word on one side, and an irregular inkblot on the other side. There is a second deck of 70 game cards, each of which has a pattern of holes punched through the card.

On each turn, a player takes one of the blackout word cards and places the pattern side underneath the game card. The number of black dots showing is the number of letters in that word card that appear in the game card's word.

Using a scorecard that lists each of the 26 word cards, the player must try one word card after another to determine the six letters represented by his game card, and then work out the right order for the actual word.

The rules provide 5 variants for two players, two variants for party fun, and one for solitaire. In head-to-head play, the player who takes the most cards to succeed loses points equal to his number of turns minus the number taken by his opponent, plus a flat penalty of 3 points for losing. First player to 50 points loses the game.