Probability: Rock Paper Scissors

Australian curriculum number (ACMSP144; ACMSP145; ACMSP146)

Students calculate their chance of winning in a game of Rock Paper Scissors and in the variant Rock Paper Scissors Lizard Spock. They look at how knowing how people are likely to behave can change the odds of winning, and decide which form of the game is "fairest".

This sequence is for students who:

  • are familiar with calculating the probabilities of different events.
  • are ready to apply their understanding of fractions to express the probability of events occurring.


Lesson 1: How Random Is It?

Students determine their chances of winning Rock Paper Scissors, then test their chances by playing against another player and in a simulation card/dice game. Students look at the psychological aspect of the game and recognise that there is a strategy to increase your chance of winning.

Lesson 2: Which Is Better?

Students calculate the probabilities of winning the game ‘Rock Paper Scissors Lizard Spock’ and compare it to the chances of winning Rock Paper Scissors. They decide which is the better game to play in different circumstances.


Last updated December 21 2018.