Deluxe Mastermind HD 1.0

Mastermind or Master Mind is a code-breaking game designed for two players. The modern version with pegs was developed in 1970 by Mordecai Meirowitz, an Israeli postmaster and telecommunications expert, originating from an earlier pencil and paper game known as Bulls and Cows, possibly with roots dating back over a century.

The game begins with the iPhone selecting a pattern consisting of four code pegs, permitting duplicates. This means it’s possible for the iPhone to select four code pegs of the same color.

In Mastermind, the player’s objective is to uncover the pattern within ten attempts, respecting both the correct order and colors. To make a guess, the player positions a row of code pegs on the decoding board. Subsequently, the iPhone gives feedback by placing from zero to four key pegs in the small holes of the row representing the guess. Each colored or black key peg signifies a correct code peg in terms of both color and position. Alternatively, an orange key peg indicates a correct color code peg placed in the wrong position.

If there are identical colors in the guess, not all can receive a key peg unless they match the number of duplicate colors in the hidden code. For instance, if the hidden code is red-red-yellow-yellow and the player guesses red-red-red-yellow, the iPhone will award two colored key pegs for the two correct reds, no key for the extra red since it doesn’t correspond to one in the code, and one colored key peg for yellow. The player won’t be informed about the presence of a second yellow in the code.

After receiving feedback, another guess is proposed. This guessing and feedback cycle persists until either the codebreaker accurately guesses the code or exceeds a maximum number of incorrect attempts (twelve, ten, or eight).

In 1977, Donald Knuth famously demonstrated that any pattern can be solved in five moves or fewer.