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Play Mastermind with the rules at hand

A small practice goal

A careful first move helps you understand the round. Check guess records your attempt. Exact means correct colour and position; misplaced means correct colour in another position. Start a new round when you are ready to try again.

What the game asks you to do

A careful first move helps you understand the round. Deduce a hidden four-colour code within ten guesses, using exact and misplaced feedback. Try the rule on the board, then read the next instruction.

Step by step

  1. The computer chooses four positions from six colours; repeated colours are allowed.
  2. Select a code position and then choose a colour. Fill all four positions.
  3. Check guess records your attempt. Exact means correct colour and position; misplaced means correct colour in another position.
  4. Each secret peg can match only one guess peg. Use the feedback to narrow the next guess.
  5. Find all four exact positions to win. After ten unsuccessful guesses the secret code is revealed.

The controls to know

Begin with the basic rule, then follow the result of your action. Tap one of four positions, then a labelled colour button. Numbers identify colours as well as the swatches. Press Check guess only when all slots are filled. Start a new round when you are ready to try again.

Put the rules into context

A careful first move helps you understand the round. For secret 1,1,2,2 and guess 1,2,1,3, feedback is one exact and two misplaced. The extra 3 has no match. Try the rule on the board, then read the next instruction.

Keep this in mind

Keep the goal in view while choosing a move. Four misplaced matches do not mean four exact positions. Also, repeated colours must not be counted more times than they appear in the secret. Start a new round when you are ready to try again.

Helpful answers for players

When I start, what is the aim of Mastermind?

Deduce a hidden four-colour code within ten guesses, using exact and misplaced feedback. No download or player account is required.

How do the controls work?

Tap one of four positions, then a labelled colour button. Numbers identify colours as well as the swatches. Press Check guess only when all slots are filled. The controls work with mouse or touch.

When I start, can you show an example?

For secret 1,1,2,2 and guess 1,2,1,3, feedback is one exact and two misplaced. The extra 3 has no match. The controls work with mouse or touch.

When I start, which mistake should I avoid?

Four misplaced matches do not mean four exact positions. Also, repeated colours must not be counted more times than they appear in the secret. You can start a new round from the game controls.

On this page, what rules and limits are used here?

Four positions, six colours and ten guesses, with repeated colours allowed. This is an independently coded free colour-code puzzle, not an official branded edition. No download or player account is required.

How many people can play here?

Solo. This is local browser play, not internet matchmaking. The worked example offers another way to follow the rule.

For this game, can the secret repeat a colour?

Yes. Any of the six colours can appear more than once. Scores here do not represent cash or prizes.

What does misplaced mean?

The guessed colour appears in the secret but not at that position, after exact matches have been accounted for. The controls work with mouse or touch.

Are colour numbers part of the rules?

They are labels for accessibility; the number and its colour refer to the same peg choice. The instructions above use these same rules.

During a round, can I see the answer?

The answer is shown when you solve the code or use all ten guesses. The game is played locally in your browser.