There are twelve official rules of basketball established by the National Basketball Association.
The following are general summaries of the basic rules of play. For official court measurements, diagrams, and other detailed information visit the Official Rules of the NBA.
- Successful field goals and free throws score one point.
- Goals made from inside or on the three-point field goal line are worth two points.
- Goals made from outside the three-point field goal line gain three points.
- The shooter must have at least one foot on the floor outside the three-point field goal prior to shooting.
- The shooter must not touch the floor on or inside the goal line.
- Only after the ball is released may the shooter contact the three-point field goal line or step into the two-point field goal area.
A successful free thrown into the basket earns one point. Unsuccessful attempts tapped into the basket are worth two points and awarded the player who tapped it in. In the case of a discrepancy, the running score is official.
Field Goal Violations
It is counted as a violation for a player to attempt a field goal in the opponent's basket. Should such an attempt be successful the opponent is credited two points. If a field goal accidentally enters the opponent's basket, the opponent is awarded two points.
A regulation game is divided into four periods, each period being 12 minutes long. Overtime periods are five minutes. Half-time breaks are 15, period breaks are two minutes and 10 seconds, as well as time prior to overtime periods. Teams have 30 seconds to replace a disqualified player.
Two minutes or less remaining in a period constitutes the two-minute part of the game and is announced as such.
A period ends when time expires. Exceptions include the ball being in the air when the time ends, the official's whistle sounds before the horn is blown, the ball is in the air when the horn is blown, or a request for time out is made the instant game time expires. For details on these exceptions please see Rule 5 at the official NBA website.
Ties and Overtime
In the case of a tie at the end of the fourth period, play continues for an additional 130 seconds without changing baskets. For official NBA details see Rule 5.
Stoppage and Timing Devices
The referee will stop the clock whenever there is a:
- Personal/technical foul
- Jump ball
- Floor violation
- Unusual delay
- Emergency suspension of play
The clock will also stop during the last minute of the first, second, and third periods after a field goal is made, or during the last two minutes of a regulation game or overtime following a field goal made.
These may only be granted when the ball is dead or under the control of the requesting team. For NBA details, see Section VI-X under Rule 5.
Time outs are only granted when the ball is dead, or in possession of the team requesting the time out. For exceptions see Rule 5, Section VII.
For information regarding timeout requests and time-ins, see Sections VIII-IX, Rule 5.
Live and Dead Balls
Start of the Game
Games and overtimes are started in the center circle on a jump ball. The team that begins the game puts the ball into play at the opponent's endline to start the fourth period. The throw-in player runs along the endline or passes it to a teammate who is out of bounds at the endline. The other teams puts ball into play in the second and third periods. After a dead ball, play is resumed by a jump ball, throw-in or a free thrower. For details on infractions and exceptions, see Section I, Rule 6.
The ball is considered live when comes into play. It comes into play when legally tapped on a jump ball, released by the throw-in player or by the free throw shooter on an official free throw.
The ball is considered dead when an official sounds the whistle, a free throw is botched, or after a good field goal until the ball becomes out-of-bounds. For exceptions see Section IV, Rule 6 of official NBA rules.
A jump ball is put into play at the circle closest to where a held, or out-of-bounds ball occurs or when it is unclear about who last touched the ball. See Rule 6, Section VI and VII for details and restrictions regarding jump balls.
Out-of-bounds and Throw-ins
A player in considered out-of-bounds when he contacts the floor or object on or outside the boundaries.
A ball is out-of-bounds when:
- It touches a player who is out-of-bounds, another person, the floor, or object on, above or outside the boundaries.
- A ball rebounds or passes behind the backboard from any place considered out-of-bounds.
- The last player who touched the ball causes it to go out-of-bounds.
- The ball is touched by two players at once causing it to go out-of-bounds.
Other rules pertaining to out-of-bounds:
After the ball becomes out-of-bounds the offensive team must designate a player to throw it back in, and it is thrown back in nearest the spot it went out-of-bounds. Only in the case of a substitution or 20-second timeout will the designated thrower-in be changed.
They start when:
- The ball is tossed in by the designated thrower-in within the five seconds allowed, at which time other players may not interfere with the thrower-in.
- On a botched throw-in, the ball is returned to the original throw-in place.
- Following a score, field goal, or free throw resulting from a personal foul, a player not credited with a score may put the ball into play from any out-of-bounds place near spot the points were earned.
- After a free throw violation by the shooter or teammate, the throw-in is made from the endline, at which time the 5-second rule still applies.
For additional rules and exceptions see Section III, Rule 8 of the official NBA website.
The Free Throw
- The free throw shooter will put the ball into play. The shooter will be positioned above the free throw line and inside the upper half of the free throw circle. This applies to every time a free throw is in order.
- In the case of personal foul free throws, the spaces nearest the endline will be filled by opponents of the shooter. Teammates occupy the adjacent spaces on either side.
- A player not filling a free throw lane space must be behind the three-point line.
- In the case of the ball becoming dead on the last free throw, players are not to be in position along the free throw lane, and no players are allowed inside the free throw line.
The Free Throw
- The person against which a personal foul is made is awarded a free throw. For details see Section II of Rule 9.
- Free throwers have 10 seconds to attempt a goal from the time they are handed the ball. After a goal is made, it is put into play by a throw-in.
For specifics on violations and penalties, and rules about interference, fouls and more, see Rules 10-12 at the official NBA website.