← Back

Activity 2.8 Rock, Paper, Scissors Game

---

Introduction

Rock, Paper, Scissors is more than just a childhood game—it’s a timeless classic that’s perfect for friendly competition. Here’s a quick overview of the rules:

Choose your move: Rock, Paper, or Scissors

• Rock crushes Scissors
• Paper covers Rock
• Scissors cuts Paper

In this activity, you’ll develop a digital version of Rock, Paper, Scissors. Not only will it sharpen your coding skills, but it will also give you a deeper understanding of how to implement logic and control flow in your programs.

Skills to Practice

• Writing while loops
• Nesting code blocks

---

Instructions

Setup

1. Create a new C# console application. Name the project 2.8 Rock, Paper, Scissors.
2. Click Create.

Code

int wins = 0;
int losses = 0;
int round = 1;
bool playing = true;
Random random = new();
Console.WriteLine("--- ROCK, PAPER, SCISSORS ---");

/* This is a multi-line comment.
   1. Set the header: round number, wins, losses
   2. Prompt user for player hand
   3. Generate a random computer hand
   4. Check who won
       i. If same hand - tie
      ii. If player chooses rock
         a. Computer paper - lose
         b. Computer scissors - win
     iii. If player chooses paper
         a. Computer scissors - lose
         b. Computer rock - win
      iv. If player chooses scissors
         a. Computer rock - lose
         b. Computer paper - win
   5. Prompt user to play again
*/

while (playing)
{
    Console.WriteLine($"\nROUND {round}!");
    Console.WriteLine($"W: {wins} - L: {losses}");
    Console.WriteLine("Rock, Paper, Scissors?");
    Console.Write("-> ");
    string player = Console.ReadLine().ToLower();
    
    int randomNumber = random.Next(0, 3);
    string computer;

    if (randomNumber == 0)
    {
        computer = "rock";
    }
    else if (randomNumber == 1)
    {
        computer = "paper";
    }
    else
    {
        computer = "scissors";
    }

    Console.WriteLine($"Computer chooses {computer}!");

    if (player == computer)
    {
        Console.WriteLine("Tie!");
    }
    else if (player == "rock" && computer == "scissors")
    {
        Console.WriteLine("You win! Rock crushes scissors!");
        wins++;
    }
    else if (player == "rock" && computer == "paper")
    {
        Console.WriteLine("You lose! Paper covers rock!");
        losses++;
    }
    else if (player == "paper" && computer == "rock")
    {
        Console.WriteLine("You win! Paper covers rock!");
        wins++;
    }
    else if (player == "paper" && computer == "scissors")
    {
        Console.WriteLine("You lose! Scissors cuts paper!");
        losses++;
    }
    else if (player == "scissors" && computer == "paper")
    {
        Console.WriteLine("You win! Scissors cuts paper!");
        wins++;
    }
    else if (player == "scissors" && computer == "rock")
    {
        Console.WriteLine("You lose! Rock crushes scissors!");
        losses++;
    }
    else
    {
        Console.WriteLine("Invalid input. Please choose Rock, Paper, or Scissors.");
    }

    Console.Write("Play again (yes/no)? ");
    string playAgain = Console.ReadLine().ToLower();
    if (playAgain == "no")
    {
        playing = false;
    }
    else
    {
        round++;
    }
}

Debug

--- ROCK, PAPER, SCISSORS ---

ROUND 1!
W: 0 - L: 0
Rock, Paper, Scissors?
-> rock
Computer chooses rock!
Tie!
Play again (yes/no)? yes

ROUND 2!
W: 0 - L: 0
Rock, Paper, Scissors?
-> paper
Computer chooses scissors!
You lose! Scissors cuts paper!
Play again (yes/no)? yes

ROUND 3!
W: 0 - L: 1
Rock, Paper, Scissors?
-> scissors
Computer chooses rock!
You lose! Rock crushes scissors!
Play again (yes/no)? no

---

Tips, Tricks, and Reflection

• You can also try rewrite the code to use nested if statements within each player choice to avoid using logical and &&. But more nesting == more headaches.
• Try making a two player version of rock, paper, scissors. When player one’s turn is done, you can call the method Console.Clear() to clear the screen, so player two peek at the previous choice:

Console.Clear();

• For a more advanced version, consider upgrading the game to include Rock, Paper, Scissors, Lizard, Spock!
• As your applications become more complex, it’s crucial to outline the requirements beforehand. The multi-line comment in the activity code is a simple yet effective guide to keep track of what needs to be implemented in the program.