Mastermind (board game)

Mastermind or Master Mind (Hebrew: בול פגיעה, romanized: bul pgi'a) is a code-breaking game for two players invented in Israel. It resembles an earlier pencil and paper game called Bulls and Cows that may date back a century.

Mastermind was invented in 1970 by Mordecai Meirowitz, an Israeli postmaster and telecommunications expert. After presenting the idea to major toy companies and showing it at the Nuremberg International Toy Fair, it was picked up by a plastics company, Invicta Plastics, based near Leicester, UK. Invicta purchased all the rights to the game, and the founder, Edward Jones-Fenleigh, refined the game further. It was released in 1971–72.

The game is based on a paper and pencil game called Bulls and Cows. A computer adaptation was run in the 1960s on Cambridge University’s Titan computer system, where it was called "MOO". This version was written by Frank King. Other versions were written for the TSS/8 time-sharing system by J.S. Felton, for Unix by Ken Thompson, and for the Multics system at MIT by Jerrold Grochow.

Since 1971, the rights to Mastermind have been held by Invicta Plastics. (Invicta always called the game Master Mind.) They originally manufactured it themselves, though they have since licensed its manufacture to Hasbro worldwide, with the exception of Pressman Toys and Orda Industries, who have the manufacturing rights to the United States and Israel, respectively. Chieftain Products acquired the rights to manufacture in Canada in 1972, though they went out of business in 1996.

Starting in 1973, the game box featured a photograph of a man in a suit jacket seated in the foreground, with a young woman standing behind him. The two amateur models (Bill Woodward and Cecilia Fung) reunited in June 2003 to pose for another publicity photo.

In 2025, toy company Goliath entered a multi-year agreement with Hasbro to become the worldwide manufacturer and distributor of the Mastermind brand.

The game is played using:

The two players decide in advance how many games they will play, which must be an even number. One player becomes the codemaker, the other the codebreaker. The codemaker chooses a pattern of four code pegs. Players decide in advance whether duplicates and blanks are allowed. If so, the codemaker may choose up to four same-colored code pegs or four blanks. If blanks are not allowed in the code, the codebreaker may not use blanks in their guesses. The codemaker places the chosen pattern in the four holes covered by the shield, visible to the codemaker but not to the codebreaker.