This is a pencil-and-paper version of the game soccer. Two players compete to get the ball into the opposing player's goal, scoring a point. Each point is played on a different field, and there are two fields per page.
The first player with 3 points wins the game.
The ball starts at the center of the field (marked by a small circle). For the first point, flip a coin to decide who goes first; for later points, the player who just scored goes second.
On your turn, draw a line segment from the ball's current position, along the edge or diagonal of a square to the next intersection. You may not draw along an edge or diagonal that has already been drawn. (You may, however, cross an existing diagonal).
If this is the first time the ball has reached that intersection, then the ball stops there, and the next player takes their turn.
If the ball has already been at that intersection, then the ball bounces—you must take another turn, drawing another line. The ball keeps bouncing until it reaches an intersection that it has never been at before.
If the ball reaches the back edge of the opposing player's net, then you score a point. If neither player has reached 3 points, then start again on a fresh field.
When the ball reaches the edge of the field, marked by a heavier line, it always bounces. You may not move along the edge of the field.
If you reach a position where you can't make a valid play, then the opposing player gets the point. Start the next point on a fresh field.