To set up this classic two-person game, create a grid of dots (10 down, 10 across) on a piece of paper.
Players then take turns drawing a vertical or horizontal line between pairs of dots. When a player completes a box, she writes her initials inside it and takes another turn; if she can complete another box, she goes again, continuing until she can no longer finish a box with a single line.
When all the boxes are filled, the player whose initials appear most often is the winner.