Tabletop games
Mastermind
HasbroMordecai Meirowitz1971
- players
- 2
- minutes
- 15
- years
- 8+
In the box
1 board with holes · Coloured code pegs · Black and white key pegs
Where to buy it
Near you and online
In a shop
Within 50 km.
Online
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The basics
The codemaker secretly sets a code of four pegs from six colours, which the codebreaker must guess in ten attempts at most. For each guess, the codemaker answers with a black key peg for each peg of the right colour in the right place and a white one for each right colour in the wrong place, without saying which. The codebreaker scores the number of attempts used (eleven on a failure); swap roles each round, and the lowest total wins.
The rules, step by step
Setup
4 secret pegs, 6 colours, 10 attempts
- One player secretly sets a code of four pegs from six colours.
- Repeated colours are allowed, unless otherwise agreed in advance.
- The other player has ten attempts.
How to play
The codebreaker guesses, Black: right place, White: wrong place
- The codebreaker proposes a code of four pegs.
- The codemaker answers with key pegs: a black one for each peg of the right colour in the right place, a white one for each peg of the right colour in the wrong place.
- The key pegs do not say which pegs they refer to: that is the whole game.
Scoring
Attempts used, Failure counts 11, Lowest total
- The codebreaker scores the number of attempts used.
- The lowest total wins: swap roles each round, otherwise the comparison is meaningless.
- Failing after ten attempts counts as eleven: without that, giving up would be better than searching.
End of the game
Code found, Or 10th attempt, Even number of rounds
- The round stops when the code is found, or at the tenth attempt.
- Play an even number of rounds, so that everyone has set as many codes as they have broken.
House rules and pitfalls
Five attempts are always enough for an optimal player with four pegs and six colours: it is a proven result.
- Five attempts are always enough for an optimal player with four pegs and six colours: it is a proven result.
- Starting with only two colours, such as red-red-blue-blue, gives more information than a varied guess.
Going further
Frequently asked questions · In the same family
Frequently asked questions
What is the maximum number of guesses needed to win?
Five, with perfect play, in the classic version with four pegs and six colours. Knuth proved it in 1977: no code can hold out against an optimal strategy beyond five attempts.
What do the black and white pegs mean in Mastermind?
A black peg means a peg of the right colour in the right place; a white peg, a peg of the right colour in the wrong place. The codemaker does not say which pegs they refer to: it is up to the codebreaker to work it out.
How many attempts do you get in Mastermind?
Ten, for a code of four pegs from six colours. In Marquoir, a code not found after ten attempts counts as eleven, and roles are swapped each round.