### Traffic Lights

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 line wins.

### Achi

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.

### Jumping Reindeer

A game for 1 person to develop stategy and shape and space awareness. 12 counters are placed on a board. Counters are removed one at a time. The aim is to be left with only 1 counter.

# Nim-7

##### Stage: 2 Challenge Level:

A group of children from Manorfield Primary School, Stoney Stanton played this game.

D.H and N.L. said:

If there is one left take it.
For $2$, take both pieces.
If you face $3$ counters and it is your turn you have definitely lost.
If there are $4$ counters left, it is essential to take $1$.
For $5$, take $2$ instead of $1$.

S.W. took these ideas further and came up with some instructions for how to win from the beginning of the game:

The idea of the game is to take the last $1$ or $2$ pieces to win. This ancient game has a theory.

If you go first you can win each time, however when you go second, it depends on what your opponent does for his/her first move.

Go first:
Take $1$ piece, then if your opponent takes $1$ piece, take $2$ pieces to win.
If your opponent takes $2$, (after you took $1$) then take $1$ to win.

Go second: If you go second, then it all depends on what the first person does. If your opponent takes $1$ piece, then you might not win. If your opponent takes $2$, then take $2$ pieces to win.

Well done! I wonder whether anyone can explain why these ideas work?