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
Steroid use in American football approximately 20 percent of the players on a football team to test on a specific day. Anabolic steroids and other performance-enhancing drugs are also used throughout high school football. Steroid use at this level of play doubled from 1991 to 2003, with results of a survey showing that about 6 percent of players out of the 15,000 surveyed had admitted to using some type of anabolic steroid or performance-enhancing drug at one point in their playing time. Other data shows that only 4 percent of high schools have some form of drug testing program in place for their football teams.