Key (basketball)

The key, officially referred to as the free throw lane by the National Basketball Association (NBA) (and Euroleague), the National Collegiate Athletic Association (NCAA), the National Association of Intercollegiate Athletics (NAIA), and the National Federation of State High School Associations (NFHS), and the restricted area by the International Basketball Federation (FIBA), is a marked area on a basketball court surrounding the basket, where much of the game's action takes place.

It resembles a locksmith's key and consists of what is colloquially known as the circle and the post, also known as the lane or the paint, overlapping at the bottom half of the circle. It can be considered a lane showing the path to the basket, and is usually painted in a distinctive color. The post is bounded by the baseline, the free-throw line, and two lane lines connecting free throw line and baseline.

Dimensions of the key area have varied through the history of the game. The lane used to be only 6 feet wide, better resembling the keyhole of a warded lock. In the NBA, the success near the basket of tall center George Mikan led to widening the lane to 12 feet, and similarly Wilt Chamberlain led to the widening of the lane to 16 feet. Since the 2010 FIBA rule amendments (implemented following the 2010 FIBA World Championship), its shape is rectangular for games sanctioned by all three associations, 16 feet (4.9 m) wide for both NBA and FIBA keys, and 12 feet (3.7 m) for NCAA and NAIA keys. Prior to 2006, the key in FIBA-sanctioned tournaments was a trapezoidal shape.

The most-commonly enforced rule on the key is the "three seconds rule" in which the team of a player on offense who stays on the key for more than three seconds loses possession of the ball. Another rule is the lane violation which occurs if a player from either team enters the key before a free-throw shooter releases the ball in the act of shooting, with the penalty of no basket if the shooter's team stepped over, and a penalty of a redo if the opposing team stepped over. A recent innovation is the introduction of the restricted area arc directly underneath the basket where the defending player cannot force an offensive foul on the opposing player.