It's a game wherein two teams of nine players each attack one end of the pitch, and defend the other end. The teams pass an oval ball between themselves with the use of their hands and feet and attempt to score 'tries' (by touching the ball down in the scoring zone) or 'field goals' (by kicking the ball over the post).
At the kick off, the team in possession must kick the ball forward from their own penalty area, and usually the opposing team takes possession. The team then in possession now has four 'downs' (called an 'over') to run to the ten yard marker. At each down, the opposing pitcher throws the ball to the quarterback, who hits the ball as far as possible with a wooden bat. The linemen then block the runner while the linebackers attempt to catch or retrieve the ball and throw it to the man on base. If the linebackers catch the ball, the quarterback is out. If after these four downs the team in possession haven't reached the ten yard marker, they surrender possession to the other team. If they do reach the marker, they get another set of downs.
A team scores six points for a try, and three for a field goal.