Activity

# Rock, paper, scissors

Beginner | MakeCode, Python | Accelerometer, LED display | Randomisation, Selection

## Step 1: Make it

### What is it?

Play this classic game with two micro:bits and learn about selection, variables and random numbers at the same time.

### How it works

• Rock, paper, scissors is a classic game of chance for two people. You and a partner shake your fists 3 times and then make gestures at random to show a rock, paper or scissors. Rock beats scissors, scissors beat paper and paper beats rock (it wraps the rock!).
• When the micro:bit accelerometer detects a shake movement, it sets the variable tool to a random number: 0, 1 or 2.
• We use 0 because computers start counting at 0, and it’s good to remember that 0 is a number!
• The program uses selection to decide what image to show on the LED display. If the random number was 0, it shows a rock icon, if it was 1 it shows the icon representing paper. If it wasn’t 0 or 1, it must be 2 because we instructed the micro:bit to only pick random numbers between 0 and 2, so in that case it shows scissors.

### What you need

• 2 micro:bits (or MakeCode simulator)
• MakeCode or Python editor
• battery packs (optional)
• a partner to play with

## Step 3: Improve it

• Draw your own icons for rock, paper, scissors.
• Think of other tools that could replace rock, paper and scissors or invent new rules.
• Use the micro:bit radio function to make a game that knows if you won or lost by communicating with your friend’s micro:bit.