Random Numbers and Games in Python

Surprise the player

What makes a game fun? Often it's not knowing what will happen next. A dice could land on any number. A card could be any card. An enemy could appear anywhere. To build games like this, your program needs to make random choices — and Python has a whole toolbox for exactly that, called the random module.

In this lesson you'll learn to roll dice, pick random items, shuffle lists, and build a complete guessing game. If you can already write your first Python program, you're ready to go.

Turning on the magic: import random

The random tools don't load by themselves. You switch them on with one line at the top of your program:

import random

import tells Python "go and fetch the random module so I can use it." After this line, you can call any random function by writing random. followed by its name. Forget the import and Python will complain that it doesn't know what random is.

Rolling dice with randint

The most useful tool for games is randint. It picks a whole number between two values — and both ends are included:

import random

roll = random.randint(1, 6)
print("You rolled a", roll)

random.randint(1, 6) can give you 1, 2, 3, 4, 5 or 6 — exactly like a real dice. Run the program a few times and you'll get different numbers. Want a twenty-sided dice? Use random.randint(1, 20). Want a coin? random.randint(0, 1) gives 0 or 1.

The "both ends included" rule is important. Some random tools stop just before the top number, but randint does not — so randint(1, 6) really can land on 6.

Picking from a list with choice

Sometimes you don't want a number — you want the computer to pick one thing from a set of options. That's random.choice:

import random

colours = ["red", "green", "blue", "yellow"]
picked = random.choice(colours)
print("The computer chose", picked)

answers = ["Yes", "No", "Maybe", "Ask again later"]
print("Magic 8 ball says:", random.choice(answers))

random.choice(colours) reaches into the list and grabs one item at random. This is perfect for a magic 8-ball, a random superhero generator, or choosing which question to ask in a quiz.

Shuffling with shuffle

Imagine a deck of cards. To deal a fair game you must shuffle it first. random.shuffle mixes a list into a random order:

import random

deck = ["Ace", "King", "Queen", "Jack", "10"]
random.shuffle(deck)
print(deck)

One important detail: shuffle changes the original list in place. It does not hand you a new shuffled list — it rearranges the one you gave it. So you write random.shuffle(deck) on its own line, not deck = random.shuffle(deck). (If you did the second, deck would become None, because shuffle returns nothing.)

A bonus: random() for decimals

If you ever need a random decimal between 0 and 1, use random.random():

import random

chance = random.random()   # something like 0.732...
if chance < 0.5:
    print("Heads")
else:
    print("Tails")

This is handy when you want something to happen "half the time" or "1 in 4 times" — you compare the decimal against a threshold.

Worked example: a number-guessing game

Let's put it all together into a complete, playable game. The computer picks a secret number and you try to guess it, getting "too high" or "too low" hints.

import random

def guessing_game():
    secret = random.randint(1, 100)
    guesses = 0
    print("I'm thinking of a number between 1 and 100.")

    while True:
        guess = int(input("Your guess: "))
        guesses += 1

        if guess < secret:
            print("Too low! Try higher.")
        elif guess > secret:
            print("Too high! Try lower.")
        else:
            print(f"Correct! The number was {secret}.")
            print(f"You got it in {guesses} guesses.")
            break

guessing_game()

How it works:

1. secret = random.randint(1, 100) picks the hidden number. Because it's random, every game is different.
2. The while True: loop keeps asking until you win. int(input(...)) turns your typed answer into a number so it can be compared.
3. guesses += 1 counts each attempt.
4. The if / elif / else gives a hint, or — when guess == secret — congratulates you and breaks out of the loop.

Try playing smart: guess 50 first, then halve the range each time. You can always win in 7 guesses or fewer! That trick is called binary search.

Try it yourself

Build a dice game for two players:

• import random and write a function roll() that returns random.randint(1, 6).
• In a loop that runs 3 times, roll for Player 1 and Player 2, print both rolls, and add each to a running total. Use a loop to repeat the rounds.
• After 3 rounds, compare the totals and print who won (or "It's a tie!").
• For a challenge, use random.choice(["⚔️", "🛡️", "🏹"]) to give each player a random weapon emoji each round, just for fun.

Once you're comfortable with randomness, try mixing it into a quiz — see building a quiz app in Python and use random.shuffle to ask the questions in a different order each time.