# Activity: Rock, paper, scissors For this activity, each student will need a micro:bit. Everyone will create the same program, the classic rock paper scissor game. ![Rock, paper, scissors](/static/courses/csintro/conditionals/rock-paper-scissors-items.png) ## Introduce activity * Have students recall the classic rock paper scissors game. * What are the rules of the game? What are the conditionals? >Example: If Player A gets rock, and Player B gets scissors, Then Player A wins. * Have students write the pseudocode for how to play the game on the micro:bit. >Example pseudocode:<br/> On button A press: choose random number from 0-2 If random number = 0, then display rock icon, Else if random number = 1, then display paper icon, Else display scissors icon. * Point out that because there are only three possibilities, we don’t need to do a separate check to see if random number = 2. So we just use an else. ## micro:bit * Working from the specifications, have students work in pairs to try to code a Rock Paper Scissors game on their own. * If students get stuck, there is a tutorial at [rock, paper, scissors](/projects/rock-paper-scissors) (steps 1 through 4), that leads students step-by-step through the process of coding a working rock paper scissor game for their micro:bit. * Let them play the game against their program. ## Ideas for Mods * Add a way to keep score: Steps 5 through 7 in the tutorial * Mod the game to use different images or to add more options like ‘Rock Paper Scissors Lizard Spock’, Step 8 in the tutorial Here's an example mod: ```blocks let hand = 0 input.onGesture(Gesture.Shake, () => { hand = Math.randomRange(0, 3) if (hand == 0) { basic.showLeds(` # # # # # # . . . # # . . . # # . . . # # # # # # `) } else if (hand == 1) { basic.showLeds(` . . . . . . # # # . . # # # . . # # # . . . . . . `) } else { basic.showLeds(` # # . . # # # . # . . . # . . # # . # . # # . . # `) } }) input.onButtonPressed(Button.A, () => { game.addScore(1) basic.pause(100) basic.showString("Wins:") basic.showNumber(game.score()) }) ```