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## 'Line of Four' printed from http://nrich.maths.org/

You will need a sheet of squared paper or 'grid' paper. If you
don't have any, just rule some lines down some lined writing paper
to form squares. One hundred squares (10 by 10) makes a good size
game board, but you can use a smaller of larger grid if you
prefer.

Two players, using two different colours, take turns to mark a
'cross-road' on the grid.

The aim is to make a line of four, across, down or
diagonally.

Each 'cross-road' can only be used once.

Try to block the other player's path.

Each time you make a line-of-four draw a line through it so it can
be counted as a point.

When all the 'cross-roads' have been used, the player with the most
points wins.

In the example below, each player has had 10 turns so far. The
green player has already scored 2 points, and the red player has
only one point.