The origins of the American football point system date to versions of rugby played in the US in the 19th century. Walter Camp, who many consider the father of modern football, started a point system where the different types of goal combinations scored against one team were compared to the other team’s goal combinations. This early system was confusing and soon led Camp to rework the point system.
Camp’s revised rugby or football point system went as follows:
Field goals earned five points
Safeties earned one point
Touchdowns earned two points
Goals scored after a touchdown earned four points.
The system reflected that rugby derived from soccer, and football from rugby. Points made by kicking in a goal were considered of greater value than points scored by running the ball in to score a goal. Recognition existed that goals in a row were hard to achieve and these were awarded accordingly.
In 1897 as modern football really took shape, the football point system was almost aligned with its current scoring system. Touchdowns were given much greater value and were awarded five points, and a second touchdown goal, or extra point was given for a kick after a touchdown. Field goals were only worth three points under the new rules, but these rules changed again in 1912.
Touchdowns were given six points, as they are now, and a kick afterward earned a point. A clear shift had been made in emphasis from the kicking game to the running and passing game, and the football point system in the early 20th century reflected this. From 1912 onward, it remained a constant and well understood aspect of the game.
Since the 1912 rules, only one significant scoring feature has been added to the system. This is called the two-point conversion, which occurs after a touchdown has been scored. If the team that has just scored a touchdown can either run or pass the ball into the end zone on the next play, they are awarded two points instead of the one point for kicking the ball through the goalposts.
The two-point conversion adds an interesting element of strategy to the football point system. A good quarterback and offense can outscore another team simply by being able to affect these extra two points. It still implies an element of risk, and is usually much harder to achieve than kicking a goal through the goal posts after a touchdown. Many teams don’t even bother with attempting the two-point conversion in the new point system, since the risk of not scoring two points does not outweigh the benefits of scoring one point through a goal kick.