Short answer: In NBA rules a player who commits six personal fouls is disqualified and must leave the game, and the team substitutes another eligible player; if a team cannot field five eligible players because of disqualifications or injuries there are special procedures that allow the game to continue with penalties applied.

Explanation of the rule

  • Personal-foul limit: In the NBA a player is disqualified (fouls out) upon committing his sixth personal foul.
  • Immediate substitution: When a player fouls out the team must replace him with a substitute from the bench so the team continues with five eligible players.
  • Technicals and ejections: Separate from personal fouls, two technical fouls result in automatic ejection; technicals are recorded separately from personal fouls.

What happens if many players foul out

  • Normal case (enough bench players): Teams simply substitute bench players when starters foul out; rotations and strategy shift accordingly.
  • Unusual case (team short of five eligible players): League rules provide exceptions so the game can continue even if a team cannot field five eligible, but additional fouls by disqualified players (if allowed to remain) can lead to penalty free throws or technicals — leagues vary in wording and application.
  • Practical rarity: It is extremely rare in real NBA games for an entire bench to be exhausted by foul-outs because teams carry at least 7–8 active players and coaches manage foul trouble.

Notes about video games and casual sources

  • Video-game behavior differs: Some videogame implementations (e.g., older NBA 2K clips and forum posts) do not enforce realistic substitution when every player is flagged, and players may remain on court or the game may behave oddly; this is an implementation quirk, not the official rule.
  • Forum confusion: Fan threads sometimes mix real rules and game behavior; trust the official NBA rules for real-game procedures.

Short example (illustrative)

  1. Player A picks up his 6th personal foul — referee signals disqualification.
  1. Coach sends in Substitute B from the bench — clock resumes with five eligible players on the court.
  1. If multiple starters foul out, the coach sends in available bench players; if no eligible substitutes remain the league’s exceptional procedures and penalty mechanics apply.

Relevant sources

  • NBA Rule No. 3 (Players, Substitutes and Coaches) and Rule No. 12 (Fouls and Penalties) are the official references for disqualification, substitutions, and penalties.
  • Explanations and practical descriptions of foul-outs and team responses appear in rule summaries and how-to guides.

Bottom note
Information gathered from public forums or data available on the internet and portrayed here.