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.
Field Goals
Free Throws
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.
Timing
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.
Period Endings
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:
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.
20-second Timeouts
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.
Regular Timeouts
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.
Live Ball
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.
Dead Ball
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.
Jump Balls
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.
The Ball
A ball is out-of-bounds when:
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.
Throw-ins
They start when:
For additional rules and exceptions see Section III, Rule 8 of the official NBA website.
The Free Throw
Positions
The Free Throw
For specifics on violations and penalties, and rules about interference, fouls and more, see Rules 10-12 at the official NBA website.