 = Key ( basketball ) = 
 
 The key , officially referred to as the free throw lane by the National Basketball Association ( NBA ) and the National Collegiate Athletic Association ( NCAA ) , the restricted area by the international governing body FIBA , and colloquially as the lane or the paint , is an area on a basketball court underneath the basket bounded by the endline , the foul line and other lines which are known as freebody lines , that are usually painted ( although unpainted on some courts with painted perimeters ) . It is a critical area on the court where much of the action takes place in a game . 
 The key , in all games , starting with FIBA 's amendments to its rules in 2010 ( to be first implemented after the 2010 FIBA World Championship ) , is rectangular . Prior to 2006 , the key in FIBA @-@ sanctioned tournaments ( mostly basketball played outside the United States , and almost all international tournaments including the World Championships and the Olympics ) was trapezoidal in shape . Both NBA and FIBA keys are 16 feet ( 4 @.@ 9 m ) wide , while NCAA keys are narrower at 12 feet ( 3 @.@ 7 m ) . 
 The most @-@ commonly enforced rule on the key is the " three seconds rule " in which a player from the offensive team is prohibited from staying on the key for more than three seconds , or else the player 's team will lose possession of the ball . Another rule enforced is the lane violation in which players from both teams are prohibited to enter the lane until after the free throw shooter releases the ball from his hands ( the shooter is prohibited to enter the key until after the ball hits the rim ) . An 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 . 
 
 = = Dimensions = = 
 
 Each level of play has different specifications for the size and shape of the key : in American leagues , where the basketball court is measured in imperial units , the shape is rectangular , while in FIBA @-@ sanctioned events , which use the metric system , the shape was trapezoidal , before being changed to a rectangle as well . In addition to the bounding rectangle , the key includes a free @-@ throw circle at its " head " or " top " . 
 The width of the key in the NBA is 16 feet ( 4 @.@ 9 m ) , including the 2 @-@ foot ( 0 @.@ 6 m ) wide foul lanes ; in U.S. college ( NCAA ) and high @-@ school play , it is 12 feet ( 3 @.@ 7 m ) . 
 Beginning after the 2010 FIBA World Championship , all FIBA @-@ administered tournaments use a rectangular key 4 @.@ 9 meters ( 16 ft ) wide . From 1956 until 2010 , FIBA @-@ sanctioned tournaments used a trapezoidal key . The narrower end was on the free @-@ throw line , where it was 3 @.@ 6 meters ( 12 ft ) , while the wider end , at the end line , measured 6 meters ( 20 ft ) . 
 The free throw circle has a six @-@ foot ( 1 @.@ 8 m ) radius and is centered at the midpoint of the free throw line ; the half of those circle on the mid @-@ court side of the free throw line is painted in solid lines . In the NBA and ULEB , the boundaries of the half closer to the basket is traced in a broken line in order to space players properly for jump balls . NBA Rule 1 ( g ) requires the key to contain two 6 inches ( 15 cm ) long hash marks , 3 feet ( 0 @.@ 91 m ) from the free throw line ; the marks indicate the so @-@ called lower defensive box . The free @-@ throw line is 15 feet ( 4 @.@ 6 m ) from the perpendicular projection of the face of the backboard onto the court ; this projection is 4 feet ( 1 @.@ 2 m ) from the end @-@ line for NBA and NCAA . The projection of the center of the basket onto the court is a perpendicular distance of 1 @.@ 575 meters ( 5 @.@ 17 ft ) from the end line in FIBA tournaments , but 4 @.@ 75 feet ( 1 @.@ 45 m ) in NBA and NCAA tournaments . 
 
 = = History = = 
 
 Originally , the key was narrower than it is today and had the shape of a skeleton / basic lever lock keyhole , measuring six feet ( 1 @.@ 8 m ) wide , hence " the key " , with the free throw circle as the head , and the shaded lane as the body . Due to the narrowness of the key , imposing centers , such as George Mikan , dominated the paint , scoring at will . To counter this , the key was widened into 12 feet ( 3 @.@ 7 m ) from 6 feet ( 1 @.@ 8 m ) at the onset of the 1951 – 52 NBA season . 
 Men 's professional basketball in the United States ( notably the National Basketball Association ) widened it further to 16 feet ( 4 @.@ 9 m ) in the 1964 – 65 NBA season to lessen the effectiveness of centers , especially Wilt Chamberlain . The NCAA retains the 12 feet key to this day . 
 On April 25 , 2008 , the FIBA Central Board approved rule changes that included the changes in the shape of the key ; the key is now rectangular and has virtually the same dimensions as the key used in the NBA . In addition , the no @-@ charge semicircles formally called the restricted area arc was also created . 
 
 = = Rules = = 
 
 
 = = = Three @-@ second violation = = = 
 
 The lane is a restricted area in which players can stay for only a limited amount of time . On all levels , a team on the offensive ( in possession of the ball ) is prohibited to stay inside the lane for more than three seconds ; after three seconds the player will be called with a three @-@ second violation which will result in a turnover . 
 In American professional basketball , the defending team is also prohibited from staying in the key for more than three seconds , unless a player is directly guarding an offensive player . If a player surpasses that time , his / her team will be charged with a defensive three @-@ second violation , which will result in a technical foul where the team with the ball shoots one free throw plus ball possession and a reset of the shot clock . In FIBA @-@ sanctioned tournaments , on the other hand , the defending team is allowed to stay on the key for an unlimited amount of time . In all cases , the count resets if the shot hits the rim or if the player steps out of the lane . 
 
 = = = Lane violation = = = 
 
 When a player is shooting free throws , there are a certain number of players at the boundaries of the key , each occupying a slot traced at the boundaries of the key . In most cases , the free throw shooter is behind the free throw line , while three of his opponents are along the sides of the key , one side with two players , the other with one . Two of his opponents are situated nearest to the basket on both sides , while his two teammates are beside the two opponents closest to the basket , with the other player from the opposing team situated farthest from the basket . In the U.S. NCAA , there are as many as six players along the key , with the opposing team allowed to have as many as four players , with the same arrangement as in the NBA and FIBA but with another player facing his teammate farthest to the basket . ( See photographs to the right . ) 
 No player along the lane may enter the key until the shot is released ; the player shooting the free throw , and anyone on top of the key , should not pass the free throw line until the ball hits the rim . If any of the offensive players violate the rule , no points are awarded for the shot and , if there are no more shots remaining , the ball is given to the defending team . If a defending player is in the lane too soon , an extra shot will be awarded regardless of whether the shot was made or missed . 
 Note that in FIBA play , if the shooter commits the violation , it is an automatic turnover . If the shot is successful and the shooter does not commit a violation , but other players do commit a violation , all violations are discarded . If players from the opposing teams enter the key prior to the release of the ball , a jump ball would be done to determine who gets the possession of the ball ( NBA ) or the possession arrow rule ( for all other levels ) ; in FIBA play , that only applies if the shooter misses , since a successful attempt negates all other penalties . In all situations , lane violation penalties cannot occur if there are further free throws to be awarded . 
 
 = = = Restricted area arc = = = 
 
 In the NBA , Euroleague , and starting in 2010 , in FIBA and NCAA play , the key has an additional area , measured as an arc three feet from the basket ( collegiate ) , four feet from the basket ( NBA ) , or 1 @.@ 25 meters ( approximately 4 @.@ 1 feet ) ( FIBA ) . The area is officially known as the " restricted area " ( RA ) in the NBA , the " restricted area arc " in the NCAA and the " no @-@ charge semicircles " in FIBA . 
 Its purpose is to stop secondary defenders from taking a position under the basket in an attempt to draw the offensive foul when a player is driving to the basket . If an offensive player drives past his primary defender on the way to the basket and a secondary defender comes over , he must establish a legal position outside the RA to draw an offensive foul . If the drive starts inside the Lower Defensive Box ( LDB – this is the area from the bottom tip of the free throw circle to the end line between the two 3 ’ posted @-@ up marks ) , the secondary defender is legally allowed to be positioned inside the RA . The restricted area also does not apply if the secondary defender jumps in attempting to block the shot , the offensive player leads with his leg or knee in an unnatural motion or uses his off arm to prevent the defender from blocking his shot . The RA does not extend from below the backboard to the baseline . Therefore , if a player drives the baseline and is not attempting to go directly to the rim , the RA does not apply . 
 The restricted area arc rule was implemented in NCAA men 's basketball for the 2010 – 2011 season . The NCAA approved adding a visible restricted @-@ area arc three feet from the center of the basket in Division I men ’ s and women ’ s games for 2011 – 2012 season . The panel delayed implementation of the arc until the 2012 @-@ 13 season for Divisions II and III to allow those schools time to plan and place the restricted @-@ area arc in their home arenas . Starting with the 2015 @-@ 2016 season , the NCAA raised the RA arc to four feet from the center of the basket . 
 
 = = Terms = = 
 
 Points made on the key are termed as points in the paint or inside points . Historically , the area of the key where offensive players are prohibited from remaining longer than three seconds has been painted to distinguish the area from the rest of the court ; hence the phrase " points in the paint . " The area around the free throw circle 's farthest point from the basket is called the " top of the key " , and several plays revolve around this area , such as screens and pick and rolls . In American women 's collegiate basketball ( and for men until 2008 ) , the three @-@ point arc intersects at the top of the key , which could translate plays conducted in this area into three @-@ point field goal conversions . 
 The intersection of the free throw line and the free throw lane is referred to as the elbow of the key . 
 
 