Some basketball rules deal with time - when is the ball live, and when is it dead? What actions stop the clock from running, and when does the clock keep going? How do you make changes or perform various activities while the clock is running? Every league will have their own specific take on these rules, but the variations will be minor - there are many more similarities than differences in rules used by the NBA and your local high school league.
So here is what you should know the next time your team plays basketball. I've tried to be as general as possible, to give an idea of what you should know, but read up on the rulebook that applies to your league to double-check specifics.
Basketball Rules: Playing time
How long are the quarters, overtime periods, half time, time outs, etc. - exact times depend on the league's adopted rules, but I think many leagues have moved toward the international standards as outlined by FIBA - 40 minute games. Some leagues will play two 20-minute halves; others will play four 10-minute quarters. And some leagues likely still use the old-time version of four 8-minute quarters.
If additional time is needed - i.e., overtime periods - each additional period is usually 5 minutes long.
Basketball Rules: Starting and Stopping the Clock
The clock starts when the ball is touched by one of the players on the court. This could mean when the ball has been tossed in a jump ball and one of the jumpers has tipped it, or when the ball has been passed into play after a dead ball or at the beginning of a quarter (the clock begins when the ball is touched by a player on the court, not when it is handed to the inbounder)
The clock stops when time runs out in the quarter, or when the referee blows his whistle.
Basketball Rules: Continuation
If a player is fouled in the act of shooting and makes the shot, the shot counts as long as the shooter completes the shot using a continuous motion begun before the foul.
For example, if a player drives in for a layup, picks the ball up and takes his first step, is fouled, but continues in to take his second step and complete the layup - this basket counts as good.
If, however, the player is fouled before he picks the ball up, or if he is fouled, stops and then shoots, the basket will not count as it is not considered a continuous motion - i.e., the violation occured before the act of shooting began, and the ball is considered to have been called "dead" when the referee blew the whistle.
Basketball Rules: Held Ball
When two players of opposing teams each have firm grip on the ball and neither can wrest the ball away, the referee will blow his whistle, signaling the ball is "dead."
In some leagues, this will result in the two players having a jump ball; most leagues now use alternating possession instead of a jump ball, mainly to speed up play.
Basketball Rules: Alternating Possession
The game begins with a tip-off jump ball - if Team A gains possession of the ball at the jump, Team B then receives the next possession
i.e., at the next held ball, instead of a jump ball, Team B is given the ball to throw in. After that, possession will alternate from one team to the next, switching after each held ball / change of possession.
The team that is entitled to the next possession at the end of each period will inbound the ball at the beginning of the next period.
The scorers' table should have a possession arrow clearly displayed, pointing to the basket that is to receive the next possession.
Basketball Rules: Inbounding the Ball
Players inbounding the ball cannot move from the spot the referee puts them in.
The only exception to this is after a basket - after a team makes a basket, any member of the opposing team can inbound the ball along the baseline, and is allowed to run along the baseline if he chooses. He may also pass to another player standing out of bounds. However, remember that the team only has limited time in which to inbound the ball (usually 5 seconds) and that count begins the moment the team has control of the ball.
Basketball Rules: Time-Outs
Commonly, a time out lasts for one minute, but some leagues will have 30 second or 20 second time outs - check with your league rules.
Teams have a certain number of time outs allowed in each game - commonly, 2 time outs allowed in the first half and three in the second half, with 1 additional time out in each overtime period. Unused timeouts from the first half cannot be transferred to the second half.
Generally, time outs will only be granted during dead balls, must be requested at the scorer's table and can only be requested by the coach or assistant coach - but these rules will differ depending on your league's adopted set of rules, so again, check with your league.
Basketball Rules: Substitutions
Teams can substitute players only during dead ball situations. The player must inform the scorer's table that he wishes to enter the game, and then he waits at the table until a game stoppage is called and the referee indicates he can enter - don't enter before the referee says so.
A few more things to know about this section of basketball rules:
The ball is considered "dead" - i.e., not in play and therefore cannot be scored with - when the shot clock sounds (usually a 24 second shot clock) while a team is in control of the ball
The basket counts if the ball is in flight for a field goal and the referee blows his whistle, or the shot clock sounds, or the game clock sounds. If any of these happen before the ball leaves the shooter's hand, the basket does not count.
Teams change baskets at the half.
Additional resources to improve your game strategy:
This list of basketball rules is not in any way exhaustive, and nor is it very detailed. As I've stated, every league will have their own twist to the rules - the length of each quarter, for example, or who is allowed to call timeouts. So before you start explaining to a referee that he doesn't know what he's doing, be sure you read up on whatever rulebook your league uses.