Double game in table tennis

In addition to games between individual players, pairs may also play table tennis. Singles and doubles are both played in international competition, including the Olympic Games since 1988 and the Commonwealth Games since 2002. In 2005, the ITTF announced that doubles table tennis only was featured as a part of team events in the 2008 Olympics.

In doubles, all the rules of single play are applied except for the following.

Service

A line painted along the long axis of the table to create doubles courts bisects the table. This line's only purpose is to facilitate the doubles service rule, which is that service must originate from the right hand "box" in such a way that the first bounce of the serve bounces once in said right hand box and then must bounce at least once in the opponent side's right hand box (far left box for server), or the receiving pair score a point.

Order of play, serving and receiving

1. Players must hit the ball. For example, if A is paired with B, X is paired with Y, A is the server and X or Y is the receiver. The order of play shall be A→X or Y & B→X or Y & vice versa. The rally proceeds this way until one side fails to make a legal return and the other side scores.
2. At each change of service, the previous receiver shall become the server and the partner of the previous server shall become the receiver. For example, if the previous order of play is A→X or Y & B→X or Y, the order becomes X→B or A & Y→B or A or X→B or A & Y→A or B after the change of service.
3. In the second or the latter games of a match, the game begins in reverse order of play. For example, if the order of play is A→X or Y & B→Y or X at beginning of the first game, the order begins with X→A or B & Y→A & B in the second game depending on either X or Y being chosen as the first server of the game. That means the first receiver of the game is the player who served to the first server of the game in the preceding game. In each game of a doubles match, the pair having the right to serve first shall choose which of them will do so. The receiving pair, however, can only choose in the first game of the match.
4. When a pair reaches 5 points in the final game, the pairs must switch ends of the table and change the receiver to reverse the order of play. For example, when the last order of play before a pair scores 5 points in the final game is A→X→B→Y, the order after change shall be A→Y→B→X if A still has the second serve. Otherwise, X is the next server and the order becomes X→A→Y→B.

Expedite system

If a game is unfinished after 10 minutes' play and fewer than 18 points have been scored, the expedite system is initiated. The umpire interrupts the game, and the game resumes with players serving for one point in turn. If the expedite system is introduced while the ball is not in play, the previous receiver shall serve first. Under the expedite system, the server must win the point before the opponent makes 13 consecutive returns or the point goes to the opponent. The system can also be initiated at any time at the request of both players and pairs. Once introduced, the expedite system remains in force until the end of the match. A rule to shorten the time of a match, it is mainly seen in defensive players' games.

Grips

Though table tennis players grip their rackets in various ways, their grips can be classified into two major families of styles, pen hold and shake hand The rules of table tennis do not prescribe the manner in which one must grip the racket, and numerous grips are employed.

Pen hold

The pen hold grip is so-named because one grips the racket similarly to the way one holds a writing instrument. The style of play among pen hold players can vary greatly from player to player. The most popular style, usually referred to as the Chinese pen hold style, involves curling the middle, ring, and fourth finger on the back of the blade with the three fingers always touching one another.  Chinese penholders favor a round racket head, for a more over-the-table style of play. In contrast, another style, sometimes referred to as the Japanese/Korean pen hold grip, involves splaying those three fingers out across the back of the racket, usually with all three fingers touching the back of the racket, rather than stacked upon one another. Sometimes a combination of the two styles occurs, wherein the middle, ring and fourth fingers are straight, but still stacked, or where all fingers may be touching the back of the racket, but are also in contact with one another. Japanese/Korean penholders will often use a square-headed racket for an away-from-the-table style of play. Traditionally these square-headed rackets feature a block of cork on top of the handle, as well as a thin layer of cork on the back of the racket, for increased grip and comfort. Pen hold styles are popular among players originating from East Asian regions such as China, Taiwan, Japan, and South Korea.

Traditionally, pen hold players use only one side of the racket to hit the ball during normal play, and the side which is in contact with the last three fingers is generally not used. This configuration is sometimes referred to as "traditional penhold" and is more commonly found in square-headed racket styles. However, the Chinese developed a technique in the 1990s in which a penholder uses both sides of the racket to hit the ball, where the player produces a backhand stroke (most often topspin) known as a reverse penhold backhand by turning the traditional side of the racket to face one's self, and striking the ball with the opposite side of the racket. This stroke has greatly improved and strengthened the penhold style both physically and psychologically, as it eliminates the strategic weakness of the traditional penhold backhand.