There are two main ways for the O to move the ball towards an opponent’s end zone.

Running
This occurs when the quarterback hands the ball off to a running back, who then tries to gain as many yards as possible by eluding defensive players. The quarterback is also allowed to run with the ball.

Passing
The other method of moving the ball is to throw it. Usually, the quarterback does the passing, though there are times when another player may pass the ball to confuse the defence. Actually, anyone on the offensive team is allowed to pass the ball as long as the pass is thrown from behind the line of scrimmage. A pass is complete if the ball is caught by another offensive player, usually the “wide receiver” or “tight end”. If the ball hits the ground before someone catches it, it is called an incomplete pass. The Defensive players will try to intercept the pass in order to gain possession of the ball for their own offence.

Tackling
A player tackles the ball carrier by bringing him down until one or both of his knees touch the ground. The play is then over. A play also ends when a player runs out of bounds. When this happens, the clock also stops running, making it a valuable strategy for late in games when the offense is trying to save time.