The game uses a 3x3 square board. 2 players take turns to play,
either placing a red on an empty square, or changing a red to
orange, or orange to green. The player who forms 3 of 1 colour in a
This game for two players comes from Ghana. However, stones that were marked for this game in the third century AD have been found near Hadrian's Wall in Northern England.
Some puzzles requiring no knowledge of knot theory, just a careful
inspection of the patterns. A glimpse of the classification of
knots and a little about prime knots, crossing numbers and knot
To play the game, take cards alternately. You win if you get all the occurrences of the same letter. (e.g. AN, ON and LINE contain all occurrences of the letter N)
Can you devise a strategy so that you never lose?
Can you explain your strategy?
You can print these cards out to play if you like.
Look at all of these games. What do you notice about the strategies they employ?
We suggest tackling them in the order given.
Printable NRICH Roadshow resource.
Click here for a poster of this problem.