The objective in beach volleyball is for a player to hit the ball over the net such that it lands within the opponent's playing area, or is not legally returned to his/her own playing area. Players can make contact with the ball using any part of their body, except on the serve, which must be hit with only the hand. Each team is allowed a maximum of three hits to return the ball to the opponent's side of the court. Each time a player touches the ball it counts as one contact for the team. A player is not allowed to make contact with the ball two consecutive times, unless s/he blocks the ball at the net; if a block occurs, the blocker may hit the ball again after his/her attempted block.
All Olympic beach volleyball matches are best two-out-of-three sets. The first two sets are played to 21 points by rally scoring. The third set, if necessary, is played to 15 points. In each set, a team must win by at least a two-point margin; there is no ceiling, so play continues until one team goes ahead by two points, thus winning the game.
Typically, a point ends when: the ball touches the court, the ball is hit out of bounds, a team makes more than three contacts with the ball, a player touches the ball twice consecutively (except in the case of a block), or a player touches the net. Every time the ball hits the ground, or a team fails to return it, play is stopped and a point is awarded to the team who did not fail to put the ball back in play. Points are most often scored by a hard, un-returnable spike, or by a block that deflects a spike back into the attacking player's side of the court.
Prior to the 2004 Athens Games, only the serving team could record a point. Now, both teams are able to earn a point, no matter who served. In line with past rules, whichever team wins a point will serve to start the next one. This system, known as "rally scoring," makes a game go much faster.
Teams change sides of the court at every multiple of seven points in sets 1 and 2, and every five points in set 3 until the match is over. This is done in order to equalize the effect of the sun and wind on the outcome of the game.
- Order: A coin toss is used to determine which team will begin serving in the first set of a match. The winners of the coin toss choose: a) either to serve or receive, or b) on which side of the court they want to start. The losers make the remaining choice. For the second set, the loser of the coin toss chooses 'a' or 'b.' For the third set, a new coin toss is conducted. Immediately after the initial coin toss, each team submits a serving order that lists the rotation the two players will follow for the duration of the match.
- Duration: If the serving team wins a rally, the same player serves again. If the returning team wins the rally, it gains the serve, and the server for the next point is whichever player had not been the server when his/her team was last serving.
- Execution: When serving, a player may move freely behind the end line of the court. During the delivery of the serve, the player's foot cannot cross the end line on the ground until he or she has made contact with the ball. The server must make contact with the ball within five seconds of the first referee signaling the serve. The server can only contact the ball with one hand, or any part of the arm, but may hold the ball with both hands before starting the serving motion.
- Attack-hits: A player may perform an attack-hit at any height, as long as contact is made on the player's side of the court. A fault is called when a player contacts the ball on the opponent's side, hits the ball out of bounds, or completes an attack-hit on the opponent's serve when the ball is entirely above the height of the net.
- Block: A player may place his or her hands and arms over the net as long as the action does not interfere with the opponent's play, but a player is not allowed to touch the ball until the opponent has made an attack-hit. Any player can make the first contact with the ball after a block, including the player who initially blocked the ball. Counted as a team contact, the team has two hits after the block to send the ball back over to the opponent's side of the court. A block results in a fault if the blocker touches the ball on the opponent's side before the opponent's attack-hit, a player blocks the ball in the opponent's space from outside the antenna, or a player blocks the opponent's serve.
Ball at the net: The ball may touch the net while on its way to the opponent's court. If it is driven into the net, the players may recover it, as long as they do not use more than three hits to do so.
Player at the net: While blocking, a player may touch the ball beyond the net, as long as the player does not interfere with the opponent's play before or during the attack. A player is allowed to place his or her hands beyond the net after an attack as long as the contact was made within his/her team's playing space. As long as only three hits are used and an opponent has not touched the ball, a player may contact a ball that has crossed below the net in order to hit it to a teammate. A player may contact a ball that has crossed the net completely outside the posts in order to direct the ball to a teammate, as long as only three hits are used and an opponent has not touched the ball. Players may cross the centerline below the net or outside the poles as long as he or she does not interfere with the opponent's play. A fault is called if there is interference, or if a player or a player's clothing touches any part of the net. However, it is not a fault if the net touches a player as a result of the ball being driven into the net. Once a player has contacted the ball, the player may touch the posts, ropes or any other object outside the total length of the net, as long as this contact does not interfere with play.
While no coaching is allowed during a match, most teams will bring along a coach, scout or trainer to the Olympics to assist them during practice and to help prepare for potential opponents. However, this person is not allowed to be in contact with the team on the warm-up courts prior to a match, or during the competition.
Each team is allowed to call one, 30-second time out in each set. Players may request a time-out when the ball is out of play and before the whistle is blown to signal a serve. In sets 1 and 2, a 30-second Technical Timeout is called when the sum of the points scored by both teams reaches 21.