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
You will need seven objects, such as counters or blocks. It is a game for two players.
Place the 7 counters in a pile and decide who will go first. (In the next game, the other player will have the first turn.)
Each player takes turns to take away either one or two counters.
The player who takes the last counter wins.
Keep playing until you work out a winning strategy.
Does it matter who has the first turn?
What happens when you start the game with more counters?
Printable NRICH Roadshow resource.
There are more Nim-like games here .