The primary reason for the fair catch rule is to protect the receiver. A receiver's attention is on the incoming punt and cannot focus on the defenders running towards him. He is quite vulnerable to injury and is also at risk for fumbling the kick if the punter intentionally makes a high short kick to allow defenders time to hit the receiver. The XFL removed the fair catch rule in an effort to make the game more "extreme." The XFL however, was not the only league to do so: Canadian football and Arena football also do not have fair catch rules.
A player signaling for a fair catch is not required to catch the ball; however, after making the signal, he may not initiate contact with any member of the kicking team until the ball is touched by another player. If he does he will be penalized 15 yards for unsportsmanlike conduct. If the ball hits the ground or a member of the kicking team, the fair catch signal is off and rules for kicked balls apply. If the receiver "muffs" the ball (touches it, but then fails to field it cleanly), then the ball can be recovered by the kicking team.
A "personal foul" for kick catch interference and a 15 yard penalty is called against the kicking team if a member violates the fair catcher's right to the ball. If the receiver attempts to advance the ball after signalling for a fair catch he is penalized five yards for "delay of game". A fair catch may be followed by a snap or a type of free kick — the fair catch kick — at his team's choice, and an expired playing period may be extended if the free kick is chosen. The National Collegiate Athletic Association (USA) abolished the fair catch from its version of American football in 1950, but restored it in 1951, minus the option of kicking from the mark of the catch, which is retained in rules of the National Federation of State High School Associations and of the National Football League.
The fair catch signal can be used as a legal form of deception in the following instance: If the receiver has no intention of actually fielding the ball, but wishes it to roll in the end zone for a touchback, he may signal for a fair catch in front of where the ball will land, making the kicking team think it will not reach the end zone. Some fans see this as an abuse of the fair catch rule, and think that it should be amended to allow the kicking team to recover the ball at any point after it has touched the ground if a fair catch has been called for, which would force an end to this practice, but so far no rules committee will consider this argument.
In some forms of football a player fielding an opponent's kick must be given a certain circular unobstructed space around him in which to do so by either some or all opponents. In rugby union, rugby league, and Canadian football this applies only against members of the kicking team who are offside, and applies whether the ball is in the air, bouncing, or rolling. In Arena Football, there is no fair catch; however all members of the kicking team must refrain from penetrating the five-yard line in coverage, but only while the ball is in the air.
The various games differ as to the conditions under which a fair catch will be awarded — for example, whether the ball must be caught "cleanly", i.e. without juggling. Rugby union requires a clean catch. American football allows the ball to be juggled, but not to be intentionally batted forward to improve the position of the catch (as for a free kick at goal). Australian rules is most generous, allowing unlimited hand play with the ball before it is caught, and allowing the kick to be from any other player, regardless of team (however, the ball must have travelled 15 metres). In the 19th century in rugby and into the 20th in American and Canadian football, a fair catch was allowed from certain kicks of a teammate -- a punt-out or punt-on. Until very late in the 20th century in rugby union, a fair catch was allowed from an opponent's throw-forward (knock-on).