Mastermind is a logic game in which a player tries to guess the code created by the opponent. It was originally a board game, and before that it was played with pen and paper, but it is now available online and on mobile phones. You can also play mastermind with pen and paper if you don't have the board game or software version.
Steps
Part 1 of 2: The rules
Step 1. The opponent chooses the code
The game board has a row of holes at one end hidden from the opponent's view. The player who creates the code takes some colored pegs and places them unnoticed in this row. This is the code you will have to try to guess.
- In the computer version, the combination is usually created automatically.
- The player who creates the code has to fill in all the holes. It can use two or more pegs of the same color. For example, the combination can be green, yellow, yellow, blue.
Step 2. Make the first attempt
Now you will have to try to guess the code. Starting at the other end of the board, take the colored pegs and insert them into the first row.
For example, you could try blue, orange, green, purple. Your playset may have multiple holes or different colors
Step 3. The opponent must speak
Next to each of your rows is a small square with four small holes for four smaller pegs. These have only two colors, white and red (or black and white in some versions). The opponent will use them to give you clues. He cannot lie, and he will always have to follow these instructions:
- Each white peg means that one of the colors is right, but in the wrong position.
- Each red (or black) peg means the color is right, and it's in the right place.
- The order in which the black and white pegs are placed does not matter.
Step 4. Proceed by trial and error
In the example above, the opponent has chosen the code yellow, yellow, green, blue. The player tries with blue, orange, green, purple. The opponent observes the attempt and gives the following clues:
- The first color is blue. There is a blue in the code, but not in the first place, so he puts a white peg.
- The second color is orange. In the code it is not present, therefore no peg.
- The third color is green. There is a green in the code, and it is in the third position, so it puts a red (or black) peg.
- The fourth color is purple. It is not present in the code, so no peg.
Step 5. Proceed with the second attempt
At this point you have some clues. In our example we will have a right color in the right place and a right color in the wrong place. Give it another try.
- Try blue, yellow, orange, pink.
- The opponent gives the clues: blue is there but it is in the wrong position, yellow is in the right position, orange and pink are not present in the code.
- The opponent will put again a white and a red (or black) peg.
Step 6. Continue until you have guessed the code or until you run out of attempts
You will keep trying, using the information from all previous attempts. If you guess the code you win, if instead you run out of attempts before guessing your opponent wins.
Step 7. Switch roles and play another game
Turn the board and start playing inverted parts. This way you both have fun trying to guess the code.
Part 2 of 2: Game strategies
Step 1. Start by repeating the same color
The novice player will quickly understand that even with so many clues it is not easy to win fast, as there are many possibilities of interpretation. Start with four of the same colors, for example four blues, to have a good starting point.
There are other strategies, but this is one of the simplest. It's not very functional if your playset has more than six colors
Step 2. Use a 2-2 pattern
In the next moves use two pairs of colors, always starting with the color of the first attempt. For example, after trying four blues, try blue, blue and another color. Try them all.
- Four blue, no clues. That's okay, we will continue to use blue.
- Blue, blue, green, green. A white peg. We will keep in mind that there is a green in the code, and it must be in the first two positions.
- Blue, blue, pink, pink. A black peg. Now we know that one of the two squads is in the right position.
- Blue, blue, yellow, yellow. One black and one white peg. There must be two yellows in the code, one on the left and one on the right.
Step 3. Use logic to reorder the right colors
Once you have four clues, you should know exactly which colors the code contains but not their order. In our example, the code must contain green, pink, yellow, yellow. By splitting the code into two pairs we now also have some position information, so we should be able to win in three moves:
- With green, yellow, pink, yellow we get two white and two black pegs. This means that the first two must be reversed, or the third and fourth.
- Let's try with yellow, green, pink, yellow. We get four black pegs. The code is fixed.
Advice
- If you start with the 2-2 strategy and play perfectly you should win in five moves or less. A perfect play should take into account 1296 possible codes, so it is only viable from a computer.
- If you want to make the game more difficult, reduce the available attempts.
