Across

4. One player of the offensive backfield may be in motion before and as the ball is snapped, but he must be moving away from or parallel to the defensive team’s goal line.
6. A player using his body to obstruct an opponent. An offensive blocker must observe the restrictions on the use of hands and arms.
7. The game is divided into two halves; each half is divided into two periods, or quarters. The half is started with a kickoff. Playing time of a half is 30 minutes in college and professional football, 24 minutes in high school. Teams may leave the field at the end of the first half. Halftime intermission is 15 minutes in high school and college games, 20 minutes in professional ball.
8. The one or two point attempt after a touchdown has been scored.
9. A receiver of a kick signals for a fair catch by raising one arm directly above his/her head. She/He is then protected against being tackled when making the catch, but in signaling “fair catch,” gives up the right to advance the ball. FOUL: any infraction of the rules that will draw a penalty.
10. The area outside the sidelines and endlines including the lines; a player touching a line is considered out.

Down

1. The period of action that starts when the ball is put in play and ends when it is dead. When a team has a first down, it has four plays, or downs, in which to gain 10 yards to retain possession of the ball. If the first down is within the opponent’s 10 yard line, then the team has four downs to gain the remaining distance to the goal line.
2. Any player may pass the ball backward or to either sideline to a teammate at any time.
3. A pass caught by the defense, who can then run with it.
5. The total time of the game is divided into four quarters, or periods. In college or professional football, each period lasts 15 minutes; in high school it is 12 minutes long. Two periods make a half. Play in the first and third period begins with a kick-off. The second and fourth periods start after an exchange of goals, but play is resumed from the point where it was stopped by the end of the previous period. Before the second and fourth periods, there is an intermission of one or two minutes, but players are not permitted to leave the field.