Beach volleyball evolved from Indoor volleyball, and the two sports remain very similar:
A team scores points by grounding the ball on the opponents’ court, or when the opposing team commits a fault (error or illegal action).
Teams can contact the ball no more than three times before the ball crosses the net; and consecutive contacts must generally be made by different players.
The most important differences between beach and indoor volleyball are:
* the playing surface (deep sand rather than a hard floor), and,
* the team size (two players per team rather than six).
There are many minor differences as well, including:
* Each half of the court measures 8 by 8 meters (indoor courts are slightly larger).
* If a blocking player touches the ball, but it continues onto his side of the net, the block counts as the first contact. (The ball may be hit a second time by the blocking player)
* Open-hand dinks, where a player uses the fingertips to redirect the ball into the opponent’s court, are illegal.
* It is legal to cross under the net as long as doing so does not interfere with the opponents’ attempt to play the ball.
* Players are not required to rotate positions; they must alternate service, but there are no ‘rotation errors’.
* There is no 3-metre line.
* There are no substitutions (and no libero).
* The first team to win two sets wins the match.
* The first two sets are won by the first team to reach 21 points with a 2-point advantage.
* If a third set is necessary, it is won by the first team to reach 15 points with a 2-point advantage.
* A beach volleyball is softer (lower internal pressure) and very slightly bigger than an indoor volleyball.
* Overhand finger passes are refereed more strictly: When receiving (unless an opposing player has hit the ball downward) or attacking, overhand passes must be executed very cleanly and square to the shoulders. In practice, this means that serves are never received open-handed.
* When setting with an overhand motion, the standard for a double hit (a fault) is lower than when receiving or attacking, though still much stricter than in indoor volleyball. The standard for a lift (another fault) is less strict than in the indoor game (it is legal to hold the ball a little longer).
Complete rules for beach volleyball can be downloaded from the FIVB website