Section 4: Players/Officials
Team Composition
Each NBA team carries a roster of up to 15 players during the regular season, with an additional two-way contract slots (up to 2 players who split time between the NBA team and its G League affiliate). On game day, teams designate 13 active players who are eligible to participate; the remaining players are listed as inactive and may not play.
Player Positions
Each team fields five players on the court at any time. The five traditional positions are:
- Point Guard (PG): The primary ball-handler and playmaker, responsible for running the team's offense, calling plays, and distributing the ball. Typically the best passer and floor general on the team.
- Shooting Guard (SG): Often the team's best perimeter scorer, skilled at shooting from mid-range and three-point distance. Also contributes to ball-handling and defensive assignments on the opposing team's best wing player.
- Small Forward (SF): A versatile position combining scoring, rebounding, and defensive abilities. Small forwards are typically athletic and capable of playing both inside and outside.
- Power Forward (PF): Plays near the basket on offense, contributing scoring in the post and mid-range areas. Responsible for rebounding and interior defense. In the modern NBA, many power forwards also shoot three-pointers (the "stretch four").
- Center (C): Traditionally the tallest player on the team, anchoring the defense near the rim and scoring in the post. Modern centers increasingly operate as rim protectors, screen-setters, and short-roll playmakers.
The modern NBA has embraced positionless basketball, with many players capable of filling multiple roles. Teams frequently use lineups that do not conform to traditional position designations.
Substitutions
- Substitutions may be made during any dead ball situation (after a made basket, during a timeout, after a foul, after a violation, or at the start of a period)
- A substitute must report to the scorer's table and wait to be beckoned onto the court by an official
- There is no limit to the number of substitutions a team may make during a game
- A player who has fouled out (6 personal fouls) must be replaced immediately and may not re-enter the game
- If a team is reduced to fewer than 5 eligible players due to fouls, injuries, or ejections, the last player to have fouled out is allowed to remain in the game and is charged a technical foul for each subsequent personal foul
Game Officials (3 Referees)
Each NBA game is officiated by a crew of three referees:
- Crew Chief: The senior official with final authority on all rule interpretations and disputes. Administers the game and has sole authority to forfeit a game.
- Referee: The second official, sharing floor responsibilities with the crew chief. Assists in all calls and reviews.
- Umpire: The third official. All three referees rotate positions throughout the game (lead, trail, and slot/center) to ensure comprehensive court coverage.
Official Positioning
- Lead official: Positioned along the baseline near the basket, responsible for play around the rim, post defense, and out-of-bounds calls along the baseline
- Trail official: Positioned near the half-court line on the ball-side, monitoring perimeter play, three-point shooting, and backcourt activity
- Slot (center) official: Positioned on the opposite side of the court from the trail official, covering weak-side action and off-ball fouls
Additional Game Personnel
- Scorer: Maintains the official score, records all field goals, free throws, fouls, and timeouts
- Timer: Operates the game clock, starting and stopping it as directed by the officials
- Shot clock operator: Operates the 24-second shot clock, resetting it as required by the rules
- Replay Center: Located in Secaucus, New Jersey, the NBA Replay Center staffs officials who review plays via video to assist the on-court crew with specific reviewable matters
- Alternate official: A fourth referee is present at all games to replace any on-court official who becomes unable to continue