Comparison of American football and rugby union possession of the ball at their own 20-yard (25 yard line in College Football) line. An important difference between the two sports involves the aftermath of a score. In American football, the scoring team kicks off, except after a safety. In rugby union, the team conceding the score kicks off (in rugby sevens, a variant of rugby union featuring seven players per side, the scoring team kicks off). An American football team consists of an offensive unit, a defensive unit and a "special teams" unit (involved in kicking and kick returns). Only eleven players can be on the field at
American football field American football field American football games are played on a rectangular "Field of Play" that measures long between goal lines, and () wide. In addition, there are end zones extending another past the goal lines to the "end lines", for a total length of . When the "football field" is used as unit of measurement, it is usually understood to mean , although technically the full length of the official field, including the end zones, is . White markings on the field identify the distance from the end zone. Inbound lines, or hash marks, are short parallel lines that mark