Editing Mastermind (board game) (section)

==Gameplay and rules==
The game is played using:
* a ''decoding board'', with a ''shield'' at one end covering a row of four large holes, and twelve (or ten, or eight, or six) additional rows containing four large holes next to a set of four small holes;
* ''code pegs'' of six different colors (or more; see [[Mastermind (board game)#Variations|Variations]] below), with round heads, which will be placed in the large holes on the board; and
* ''key pegs'', some colored red (or black) and some white, which are flat-headed and smaller than the code pegs; they will be placed in the small holes on the board.
The two players decide in advance how many games they will play, which must be an [[Even and odd numbers|even number]]. One player becomes the ''codemaker'', the other the ''codebreaker''.<ref name="Fullerton">{{cite book|title=Game design workshop|last=Fullerton|first=Tracy|edition=2|publisher=[[Morgan Kaufmann Publishers]]|date=2008|isbn=978-0-240-80974-8}}</ref>{{rp|120}} 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.<ref>{{cite web|url=http://www.industrious.com/mastermind/gamerules.html|title=Industrious|access-date=7 July 2014}}</ref>

The codebreaker tries to deduce the pattern, in both order and color, within eight to twelve turns. Each attempt is made by placing a row of code pegs on the decoding board.<ref name="Fullerton" />{{rp|120}} Once placed, the codemaker provides feedback by placing from zero to four key pegs in the small holes of the row with the guess. A colored key peg is placed for each code peg from the guess which is correct in both color and position. A white key peg indicates a code peg that belongs in the solution, but is incorrectly positioned.<ref>{{cite web|url=http://mathworld.wolfram.com/Mastermind.html|title=Wolfram|access-date=9 July 2012}}</ref>

[[File:ColorCode.png|thumb|Screenshot of software implementation (ColorCode) illustrating the example.]]
If there are duplicate colors in the guess, they cannot all be awarded a key peg unless they correspond to the same number of duplicate colors in the hidden code. For example, if the hidden code is red-red-blue-blue and the codebreaker places red-red-red-blue, the codemaker will award three colored key pegs for the first two reds and the blue, but nothing for the third red. No indication is given of the fact that the code also includes a second blue.<ref>{{cite web|url=http://www.archimedes-lab.org/mastermind.html|title=Archimedes|access-date=7 October 2012}}</ref>

Once feedback is provided, another attempt is made; tests and feedback continue to alternate until either the codebreaker deduces correctly, or all rows on the decoding board are full.

Traditionally, players can only earn points when playing as the codemaker. The codemaker gets one point for each guess the codebreaker makes. An extra point is earned by the codemaker if the codebreaker is unable to deduce the exact pattern within the given number of turns. (An alternative is to score based on the number of key pegs placed.) The winner is the one who has the most points after the agreed-upon number of games are played.

Other rules may be specified.<ref>{{cite web|url=http://codebreaker-mastermind-superhirn.blogspot.de/2012/07/bulls-and-cows-mastermind-superhirn.html|title=Bulls and Cows & co.|access-date=7 July 2012}}</ref>