Section 5: Rules of Play
Game Duration
An NBA game consists of four 12-minute quarters, for a total of 48 minutes of regulation play. The game clock stops for dead balls, fouls, violations, timeouts, and other stoppages, meaning actual elapsed time is significantly longer (typically 2 to 2.5 hours).
- Halftime: A 15-minute intermission occurs between the second and third quarters (extended for nationally televised and playoff games)
- Between quarters: A 130-second break occurs between the first and second quarters and between the third and fourth quarters
- Two-minute warning: The officials notify both teams when 2 minutes remain in the fourth quarter and in any overtime period
Shot Clock (24 Seconds)
The offensive team must attempt a shot that hits the rim within 24 seconds of gaining possession of the ball. The shot clock was introduced in the 1954-1955 season to increase pace of play and scoring.
- Full reset (24 seconds): After a change of possession, after the ball goes out of bounds off the defensive team, or after a kicked ball or punched ball violation by the defense
- Partial reset (14 seconds): After an offensive rebound, after the ball goes out of bounds off the offensive team and is retained (in the frontcourt), after a kicked ball or punched ball violation by the defense in the frontcourt, after a loose ball foul committed by the defensive team, or after a jump ball situation where the offensive team retains possession
- Shot clock violation: If the shot clock expires before a valid shot attempt (one that hits the rim), the opposing team is awarded possession. The ball is inbounded from the sideline nearest to where the violation occurred.
Starting Play
- Jump ball: Each game and overtime period begins with a jump ball at center court. Two opposing players stand inside the center circle, and the referee tosses the ball upward between them. Each jumper may tap the ball after it reaches its highest point.
- Alternating possession: After the opening jump ball, all subsequent jump ball situations (held balls, simultaneous possession) are resolved using the alternating possession arrow. The team that did not gain initial possession from the opening tip receives the next alternating possession.
Ball Advancement (Backcourt / Frontcourt)
- The offensive team must advance the ball past the half-court line within 10 seconds of gaining possession in the backcourt (8-second rule in FIBA; NBA uses 10 seconds as of the current rules)
- Once the ball has been established in the frontcourt (both feet of the ball-handler and the ball are past the half-court line), the offensive team may not return the ball to the backcourt — doing so is a backcourt violation (over-and-back)
Timeouts
- Each team is granted 7 timeouts per game (no distinction between full and 20-second timeouts since the 2017-2018 season)
- Each timeout is 75 seconds in duration
- Teams are limited to 4 timeouts in the fourth quarter and may not carry more than 2 timeouts into the final 3 minutes of the fourth quarter (excess timeouts are forfeited)
- Each team receives 2 timeouts per overtime period (unused regulation timeouts do not carry over)
- Mandatory timeouts: One timeout must be taken by each team in each quarter. If no team has called a timeout by the 6:59 mark of each quarter, a mandatory timeout is charged to the home team; a second mandatory timeout occurs at the 2:59 mark if needed.
Overtime
- If the score is tied at the end of the fourth quarter, a 5-minute overtime period is played
- Overtime begins with a jump ball at center court
- Each team receives 2 timeouts per overtime period
- Additional overtime periods are played until one team has a higher score at the end of a period — NBA games cannot end in a tie
- Personal fouls carry over from regulation into overtime; team foul counts reset to zero for each overtime period
Inbounding the Ball
- After a made field goal or free throw (in non-dead-ball situations), the opposing team inbounds from behind the baseline anywhere. No timeout is needed and the 5-second inbound count begins immediately.
- After a violation, a foul resulting in a throw-in, or an out-of-bounds play, the ball is inbounded from the designated spot nearest to the infraction. The inbounding player has 5 seconds to release the pass.
- In the final 2 minutes of the fourth quarter and overtime, a team calling a timeout after a made basket may elect to inbound from the frontcourt sideline (at the 28-foot mark) instead of behind the baseline.