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Instruo

Logic

Mastermind

Crack a four-color code using exact and close-match clues.

Play immediately. No account required.

Crack a hidden four-color code. Exact pegs match color and position; close pegs match color in another position.

A raccoon codebreaker arranging colored pegs beside a vault

Code room

Preparing the lock

Runs locally in this tab. No code or guesses leave your browser.

Rules

  1. Choose four colors from the six available pegs.
  2. Exact counts show digits in the correct place.
  3. Close counts show matching digits in another place.
  4. Crack the code in eight attempts.

A brief history

Mastermind was released as a code-breaking board game in 1970. Its compact feedback system turned logical deduction into a repeatable home game.

Privacy

The code and guesses are generated and stored only in this tab.