Football is a team sport where players use their feet to pass, catch, and run the ball. It requires a lot of strength, speed, and athleticism to play. It is a high-impact sport that often leads to injuries. It is played in many countries around the world.
There are many different rules that govern the game of football. Some of the most important rules are: the field of play, the goal line, and the end zones. The field of play is a rectangular area that can be made of grass or turf and is 120 yards long. It has two 10-yard end zones on each end, and a set of field goal posts through which teams can kick field goals (more on this later).
The goal line is the line that separates the end zone from the rest of the field. A team scores by carrying the ball into one of the end zones, either running or passing it. The end zones are marked by the goal posts and a set of white lines that extend from each side of the field to the other. A player is out of bounds when they go beyond the goal line or touch the end zone line with their hands, legs, or arms.
Each team has 11 players on the field at a time. The players wear padded helmets, shoulder pads, and thigh and shin guards to protect themselves from injury. The ball used in the game is a sphere that is made of leather or synthetic material and has a circumference of 58-61 cm (21-22 in). It is inflated to a pressure of 115 psi, and is marked with a circle of 12 concentric circles that are divided into quarters, with each quarter having six small segments of equal size.
During a football game, the offensive and defensive teams alternate turns playing the ball. The first team to score points wins the game. The scoring teams can also earn extra points by kicking the ball through the uprights after a touchdown. The extra point is worth one point, and the two-point conversion is worth two points.
Football games originated in England in the 19th century. Before this, “folk football” games were played in towns and villages according to local customs with a minimal number of rules. Industrialization and urbanization reduced the amount of time available for leisure activities, which led to the development of a more structured game with organized rules. It was teachers, students, and former students at English public schools who codified these rules to enable matches between schools.
During a football game, each team has four chances, called downs, to gain 10 yards by running or passing the ball. If a team fails to gain 10 yards in four downs, they must punt or kick the ball to the other team. The team can also try to make a field goal on fourth down, which is worth three points.