Rules reference
Updated
Independent desk. Figures are traced to named sources and corrections are logged — see the editorial policy.
Four 12-minute quarters, two 20-minute halves, four 10-minute quarters — the three rulebooks look alike until you count minutes and fouls.
The basics are shared everywhere: five players a side, ten-foot rims, two points a basket and three beyond the arc. The rulebooks diverge on timing and on how much physical contact a player is allowed before leaving the game.
Game length
- NBA: four 12-minute quarters, 48 minutes in all.
- NCAA men: two 20-minute halves, 40 minutes.
- NCAA women: four 10-minute quarters, since the 2015–16 season.
- FIBA: four 10-minute quarters, 40 minutes.
Shot clock
The NBA shot clock is 24 seconds, and since the 2018–19 season it resets to 14 seconds after an offensive rebound, not to 24. FIBA also uses 24 seconds with a 14-second reset after an offensive rebound or a foul. College basketball in the United States uses a 30-second shot clock for both men and women, since the 2015–16 season.
Personal fouls
A player in the NBA is disqualified on his sixth personal foul. NCAA and FIBA players foul out on the fifth. That one-foul difference changes how stars are used: an NBA star with five fouls can still play defence, while a college or international player has to sit down.
Team fouls
Each rulebook counts team fouls per period and awards free throws once a team goes over the limit. The thresholds and the number of free throws differ between the three, and the NBA applies a separate threshold in the final two minutes of a period. The details are in the official rule books; the point to take away is that a foul late in a period can be more expensive than the same foul earlier.