A contact sport is a sport in which bodily contact is necessary. The amount of physical contact implicated varies by sport, meaning "contact" is a relative descriptor. A foul in basketball, football, and boxing all look different, but since physical contact is a major component of each game, they all qualify as contact sports. Some contact sports have non-contact variations (such as flag football for American football) which replace tackling and other forms of contact with alternative methods of interacting with an opponent, such as removing a flag from a belt worn by the opponent. Other sports may have contact, but such events are illegal under the rules of the game and are incidental or accidental and do not form part of the sport. It can also include impact via a piece of sporting equipment, such as being struck by a hockey stick or football. Non-contact sports are those where participants should have no possible means of touching, such as sprinting, swimming, darts or snooker, where players use separate lanes or take turns of play. Consideration should also be given to other sports such as motocross, BMX, and road cycling, which all involve riding/racing in packs of riders. This often results in brushing and bumping off other riders. In contact sports, not only is contact acceptable, it is encouraged in some aspects of the game (Picks, Boxing out, creating offensive space). There is a limit as to how much contact is acceptable, and a foul is called when that border is crossed. However, to say basketball isn't a contact sport would be inaccurate. Nomenclature United States of America Current medical terminology in the United States uses the term collision sport to refer to sports like rugby, American football, ice hockey, lacrosse and roller derby. The term contact sport is used to refer to sports such as basketball and handball, and the term limited-contact sport to sports like baseball, volleyball and squash. The American Academy of Pediatrics policy statement was revised in 2008 included the following definitions: Injuries Many sports will penalize contact with rules for certain situations or instances to help reduce the incidence of physical trauma or litigation for assault or grievous bodily harm. Many sports involve a degree of player-to-player or player-to-object contact. The term "contact sport" is used in both team sports and combat activities, medical terminology and television game shows, such as American Gladiators and Wipeout,