Mastermind Game using Python

Last Updated : 12 Jul, 2025

Given the present generation's acquaintance with gaming and its highly demanded technology, many aspire to pursue the idea of developing and advancing it further. Eventually, everyone starts at the beginning. Mastermind is an old code-breaking game played by two players. The game goes back to the 19th century and can be played with paper and pencil.

Prerequisite: Random Numbers in Python

Rules of the game

Two players play the game against each other; let's assume Player 1 and Player 2.

Player 1 plays first by setting a multi-digit number.
Player 2 now tries his first attempt at guessing the number.
If Player 2 succeeds in his first attempt (despite odds which are highly unlikely) he wins the game and is crowned Mastermind! If not, then Player 1 hints by revealing which digits or numbers Player 2 got correct.
The game continues till Player 2 eventually is able to guess the number entirely.
Now, Player 2 gets to set the number and Player 1 plays the part of guessing the number.
If Player 1 is able to guess the number within a lesser number of tries than Player 2 took, then Player 1 wins the game and is crowned Mastermind.
If not, then Player 2 wins the game.
The real game, however, has proved aesthetics since the numbers are represented by color-coded buttons.

For example:

Input:

Player 1, set the number: 5672
Player 2, guess the number: 1472

Output:

Not quite the number. You did get 2 digits correct.
X X 7 2

Enter your next choice of numbers:

We shall not be using any of the Pygame Libraries, to aid us with additional graphics, and therefore shall be dealing only with the framework and concept. Furthermore, we are going to be playing against the Computer i.e, the Computer would generate the number to be guessed. Below is the implementation of the above idea.

Python3

import random


# the .randrange() function generates a
# random number within the specified range.
num = random.randrange(1000, 10000)

n = int(input("Guess the 4 digit number:"))

# condition to test equality of the
# guess made. Program terminates if true.
if (n == num):
    print("Great! You guessed the number in just 1 try! You're a Mastermind!")
else:
    # ctr variable initialized. It will keep count of
    # the number of tries the Player takes to guess the number.
    ctr = 0

    # while loop repeats as long as the
    # Player fails to guess the number correctly.
    while (n != num):
        # variable increments every time the loop
        # is executed, giving an idea of how many
        # guesses were made.
        ctr += 1

        count = 0

        # explicit type conversion of an integer to
        # a string in order to ease extraction of digits
        n = str(n)

        # explicit type conversion of a string to an integer
        num = str(num)

        # correct[] list stores digits which are correct
        correct = ['X']*4

        # for loop runs 4 times since the number has 4 digits.
        for i in range(0, 4):

            # checking for equality of digits
            if (n[i] == num[i]):
                # number of digits guessed correctly increments
                count += 1
                # hence, the digit is stored in correct[].
                correct[i] = n[i]
            else:
                continue

        # when not all the digits are guessed correctly.
        # if (count < 4) and (count != 0): - this condition is not needed as we are starting with the condition, n!=num, which is, count<4
         print("Not quite the number. But you did get ",
                  count, " digit(s) correct!")
          # second code is not supposed to print the guessed numbers, from the sample output, here I get we are not recording the position of the guess,but count. But as per the explanation, the code should not print the guessed numbers, rather give their count.
            # print("Also these numbers in your input were correct.")
            # for k in correct:
            #    print(k, end=' ')
          print('\n')
          print('\n')
          n = int(input("Enter your next choice of numbers: "))

        # when none of the digits are guessed correctly.
        elif (count == 0):
            print("None of the numbers in your input match.")
            n = int(input("Enter your next choice of numbers: "))

    # condition for equality.
    if n == num:
    # ctr must be incremented when the n==num gets executed as we have the other incrmentation in the n!=num condition
        ctr+=1
          print("You've become a Mastermind!")
        print("It took you only", ctr, "tries.")

Let's suppose the number set by computer is 1564

Output:

Guess the 4 digit number: 1564

Great! You guessed the number in just 1 try! You're a Mastermind!

If the number is not guessed in one chance.

Output:

Guess the 4 digit number: 2164    

Not quite the number. But you did get 2 digit(s) correct!
Also these numbers in your input were correct.
X X 6 4

Enter your next choice of numbers: 3564
Not quite the number. But you did get 2 digit(s) correct!
Also these numbers in your input were correct.
X 5 6 4

Enter your next choice of numbers: 1564
You've become a Mastermind.
It took you only 3 tries.

You can make the game harder by either increasing the number of digits of the input or by not disclosing which numbers in the input were correctly placed. This has been explained in the code below.

Python3

import random

# the .randrange() function generates
# a random number within the specified range.
num = random.randrange(1000, 10000)

n = int(input("Guess the 4 digit number:"))

# condition to test equality of the
# guess made. Program terminates if true.
if(n == num):
    print("Great! You guessed the number in just 1 try! You're a Mastermind!")
else:
    # ctr variable initialized. It will keep count of
    # the number of tries the Player takes to guess the number.
    ctr = 0

    # while loop repeats as long as the Player
    # fails to guess the number correctly.
    while(n != num):
        # variable increments every time the loop
        # is executed, giving an idea of how many
        # guesses were made.
        ctr += 1

        count = 0

        # explicit type conversion of an integer to
        # a string in order to ease extraction of digits
        n = str(n)

        # explicit type conversion of a string to an integer
        num = str(num)

        # correct[] list stores digits which are correct
        correct = []

        # for loop runs 4 times since the number has 4 digits.
        for i in range(0, 4):
            # checking for equality of digits
            if(n[i] == num[i]):
                # number of digits guessed correctly increments
                count += 1
                # hence, the digit is stored in correct[].
                correct.append(n[i])
            else:
                continue

        # when not all the digits are guessed correctly.
        if (count < 4) and (count != 0):
            print("Not quite the number. But you did get ",
                  count, " digit(s) correct!")
            print("Also these numbers in your input were correct.")

            for k in correct:
                print(k, end=' ')

            print('\n')
            print('\n')
            n = int(input("Enter your next choice of numbers: "))

        # when none of the digits are guessed correctly.
        elif(count == 0):
            print("None of the numbers in your input match.")
            n = int(input("Enter your next choice of numbers: "))

    if n == num:
        print("You've become a Mastermind!")
        print("It took you only", ctr, "tries.")

Output:

Guess the 5 digit number: 38476

Not quite the number. But you did get 2 digit(s) correct! 
Enter your next choice of numbers: 41876

Not quite the number. But you did get 4 digit(s) correct!
Enter the next choice of numbers: 54876

Great you've become a Mastermind!
It took you only 3 tries!

Full Code Explanation:

The code starts by initializing a variable, ctr, to 0.
This will keep track of the number of tries the player makes to guess the number.
Next, the code creates a random number within the range of 1000 and 10000.
The .randrange() function generates this random number.
The next line assigns this random number to num.
Next, the code tests whether num is equal to the randomly generated number, num.
If they are equal, then the program terminates and prints "Great!
You guessed the number in just 1 try!
You're a Mastermind!"
Otherwise, it continues with the while loop.
The while loop runs as long as n!=num (which means that n cannot be equal to num).
Every time execution of this loop occurs, ctr++ increments which gives an idea of how many guesses were made.
The for loop also runs 4 times since there are 4 digits in n (0-3).
For each iteration of this loop, i in range(0,4) checks if n[i]==num[i].
If they are equal then count++; else continue is executed and k is stored in correct[] (an empty list), which will store all digits that
The code initializes a variable called ctr which will keep track of how many times the player guesses the number.
The code also creates a while loop that will repeat as long as the player fails to guess the number correctly.
In each iteration of the while loop, the code increments a variable called ctr and stores this value in a variable called count.
The code also creates a list called correct which will store digits which are correct.
Finally, the code prints out some information about what was entered into the input field and terminates if n==num.

Note: Suppose the number set by the computer is 54876.

The entire scope of modifying this code is massive. The idea here is to get a sense of what the concept is. There are plenty of games such as this one which relies on similar basic code. By utilizing this code, developing it further while incorporating libraries from Pygame, would make it more like the real deal, not to mention much more involving!

Build a Mastermind Game using Python

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