NFL
A down starts when the ball is put in play and ends when it is dead. The offense has four charged scrimmage downs to reach a line 10 yards ahead.
Guides
Downs and scoring
A down is one play. How many you get, and what a score is worth, depends on which rulebook is in force. Overtime is separate.
A down
NCAA
A series is up to four consecutive scrimmage downs. The line to gain is 10 yards in advance, unless the goal line is closer.
CFL
Team A has three downs to gain 10 yards. Miss that, and the other team takes the ball where it is dead.
The field
NFL
360 feet by 160 feet. Each goal line is 10 yards in from the end line.
NCAA
The goal lines are 100 yards apart. Each end line is 10 yards behind its goal line. Eleven players a side.
CFL
110 yards by 65 yards. The dead-ball line is 20 yards behind each goal line. Twelve players a side.
NFL players
The game is played by two teams of 11. More than 11 in the formation is a foul.
The score
Shared
In all three books a touchdown is 6, a field goal is 3, and a safety is 2.
After a touchdown
The NFL and NCAA try is 1 for a kick or safety, or 2 for a touchdown. The CFL convert is 1 from a kick scrimmaged at the 25, or 2 from a run or pass at the 3 or the 25.
The rouge
Only the CFL book has a single point. It is scored when a kick becomes dead in the opponent’s goal area, or is touched there and then goes out of bounds in the goal area.
Sources
2026 NFL Official Playing Rules