Reasoning based on this Japanese activity.
A game somewhat similar to 'noughts and crosses' on a much larger
This game is known as Pong hau k'i in China and Ou-moul-ko-no in Korea. Find a friend to play or try the interactive version online.
This very well known game for two players is always good
You make your hand into a fist for the rock, hold it flat for
paper and put two fingers out for scissors. Each player
simultaneously makes one of the signs and of course scissors beats
paper, paper beats rock and rock beats scissors.
To play this game against the computer, choose either the rock
or paper or scissors button on the left hand side. The computer
will select one at random and the score will be kept in the box
In this game both players are equally likely to choose scissors,
paper or rock. We say they choose each one with probability one
Try a version of the game which is played in China. You may need
a referee! You start the game facing each other with feet together.
Each time the loser has to step sideways so that his or her feet
are wider apart and gradually you will both be doing the splits.
Who can last longer before giving up or falling over?
To vary this game in a more mathematical way change the
probabilities for making the choices. For example suppose rock is
chosen half the time (on average) and scissors and paper one
quarter of the time each. To do this, each player could use 4 cards
and draw rock on two cards, scissors on one, and paper on one. Each
time the players simply choose one of their four cards at
What happens if one player is equally likely to choose either
scissors or paper or rock and the other player chooses rock with
probability one half, paper with probability one quarter and
scissors with probability one quarter? Who wins more often when you
play a lot of games?
Suppose you have a scoring system giving different points for
the different results.
When the choices of scissors, paper and rock are not equally
likely can you always vary the scoring system to make it a fair
SCISSORS, PAPER, ROCK TEAM GAMES
The two teams stand in parallel
lines. The players at the top of the line play and the loser goes
to the end of the line. The winning team is the first to get ten
The two teams stand in
parallel lines. On the word 'go' players challenge the member of
the opposite team next to them. Losers drop out. When the numbers
in the two teams are unequal it is the players at the head of the
line who challenge their opponents and the extra survivors watch.
Of course this gives the team with the most survivors the best
chance of winning the match but that's just life!
The variations of 'Scissors, Paper, Rock' above are discussed in
this month's article (first published on MOTIVATE
) by John Haigh called Taking Chances