Professional football teams use 7-on-7 as a drill, but high schools all over the country are playing 7-on-7 football during the summer, competing against one another in multiday tournaments.

A few questions and answers about 7-on-7 basics:

Q. How long is each game?A. Short enough that teams can play several in one day. At a national tournament in Hoover, Ala., this month, a 22-minute game clock will run continuously until the final 2:00.

Q. How big is the playing field?A. The offense starts a possession 40 yards from the end zone.

Q. First and 10?A. Nope. The offense has three downs to gain 15 yards.

Q. One-hand or two-hand touch?A. One-hand is the rule of choice for both the Hoover tournament and a 24-team event in Little Rock, Ark., last month. That cuts down on the number of long runs after the catch and places a bigger emphasis on timing and precise route running.

Q. Isn't it easy to throw without a pass rush?A. Perhaps, but the quarterback is required to throw within 4 seconds of the snap.

Q. Are there any other restrictions on the offense?A. The offense must use a legal formation, which means no more than five eligible receivers. At the Little Rock tournament, the quarterback would start each play by snapping the ball to himself off a small stool. Without a center, 7-on-7 was actually 6-on-7. At the Hoover tournament, where teams have the option of using a center to snap the ball, all passes must advance beyond the line of scrimmage. And no running plays, of course.