What Are the Rules of Football?

The game (and the second half) starts with a kickoff from one end of the field, where the defense kicks the ball to the team who's trying to score. The team on offense tries to catch it and run as far as possible up the field to advance the ball — this is called a kick return. Where the player carrying the ball is tackled is where they start the next play.

If the defense kicks the ball all the way into the offense's end zone, the player who catches the ball has the choice to kneel down (called a touchback), which means the ball will start at the 20-yard line, or he can try to run the ball up the field if he thinks he can make it farther than the 20-yard line. During kickoff, if no one catches the ball, either team can try to gain possession of it wherever it lands, as long as it's in bounds.