The three-point arc is an important marked feature of the basketball court. The arc extends around the basket in a near semicircle, and its distance from the basket differs according to the level of play. Even at one level, the distance can change as rules committees grapple with the best distance for the good of the sport. The NBA has changed the three-point distance on two different occasions since first adopting the trey, as the three-point shot is called, in the 1979-1980 season. The three-point distance was moved back to its original 23'9" for the 1997-1998 season. The college distance is 19'9", while the international distance is 20'6".

Any shot made from beyond this arc -- even a desperation half-court shot at the buzzer -- is worth three points. A three-point shooter must have both feet behind the arc as he launches this shot, but either foot is allowed to land on the other side of the arc.