Tennis rules explained: serves, faults, lets, line calls and time

The rules of tennis are set by the International Tennis Federation (ITF) in the Rules of Tennis, which the Grand Slams and the tours apply. In short: the server gets two tries to land a serve diagonally in the service box; a serve that clips the net and lands in is a let and is taken again; a ball that touches a line is in; and a player loses the point by letting the ball bounce twice, hitting it out or into the net, or touching the net while the ball is in play. This page goes through those rules in plain words, from the 2026 edition, checked on 1 November 2026.

Scoring has its own pages: how tennis scoring works for points and games, how many sets are in a tennis match for the format, and tennis tiebreak rules for tiebreaks. This one covers everything else.

The serve

• Where to stand. Before starting, the server stands still with both feet behind the baseline, between the imaginary extensions of the centre mark and the sideline (Rule 16).
• How to serve. The server releases the ball by hand in any direction and hits it before it touches the ground (Rule 16).
• Which side. In a normal game the server starts from the right half of the court and then alternates (Rule 17). The serve must go over the net and land in the service court diagonally opposite.
• Who serves. The players take turns, game by game (Rule 14).
• Being ready. The server mustn't serve until the receiver is ready, but the receiver has to play to the server's reasonable pace (Rule 21).

Faults, double faults and foot faults

A serve is a fault if the server breaks the rules on standing and serving, misses the ball when trying to hit it, or the ball hits a permanent fixture, a singles stick or a net post before landing, or touches the server or their partner (Rule 19). After a fault the server serves again from the same side (Rule 20). Two faults in a row, a double fault, lose the point (Rule 24).

A foot fault is a fault for what the server's feet do during the service motion (Rule 18). The server mustn't:

• walk or run, although slight movements of the feet are allowed;
• touch the baseline or the court with either foot;
• touch the area outside the imaginary extension of the sideline;
• touch the imaginary extension of the centre mark.

Lets

A serve is a let if it touches the net, strap or band and is otherwise good, or if it's served before the receiver is ready (Rule 22). A service let doesn't count and is simply served again, but it doesn't cancel a fault already served: a let on a second serve is still a second serve. Any other let means the whole point is replayed (Rule 23). The ITF also allows a no-let format, in which a serve that touches the net is in play.

In or out

A ball that touches a line is in: Rule 12 says it counts as touching the court bounded by that line. A ball that hits a permanent fixture, such as a fence or a stand, after landing in the correct court wins the point for the player who hit it; if it hits the fixture before landing, that player loses the point (Rule 13).

How a player loses a point

Rule 24 lists the ways. The most common are:

• serving a double fault;
• letting the ball bounce twice before returning it;
• hitting the ball out, or into the net;
• volleying a serve, that is, returning it before it bounces;
• touching the net, the net posts or the opponent's court while the ball is in play;
• hitting the ball before it has crossed the net;
• being hit by the ball, or anything you wear or carry being hit, other than the racket;
• in doubles, both partners touching the ball on a return.

Some shots that look wrong are fine. Rule 25 says a return that touches the net and lands in is good, and so is one that goes around the outside of the net post. Rule 26 covers hindrance: if an opponent deliberately hinders a player, that player wins the point, but if the hindrance is unintentional or outside the players' control, the point is replayed.

Doubles: who serves and who receives

At the start of each set, the serving team decides which player serves the first game, and their opponents decide who serves the second. Partners then take turns, so the order runs the same way through the set (Rule 14). On the receiving side, each team decides who receives the first point of its first receiving game, and the partners alternate points after that (Rule 15). Once the serve has been returned, either partner can hit the ball. The tours also use no-ad games and a match tiebreak in doubles, which the scoring and tiebreak pages explain.

Time between points, and medical time-outs

Rule 29 says play should be continuous. Players get up to 25 seconds between points, up to 90 seconds when changing ends after a game, and up to 120 seconds between sets. A player with a treatable medical condition may have one medical time-out of three minutes. How long is a tennis match? shows what those limits add up to.

What the rules do to the price

Most rules never touch the price. A few do, because they decide points at the moments that matter.

A medical time-out can move the price too, because it raises the chance of a retirement, and markets settle retirements by their own rules. What happens if a tennis player retires mid-match? explains how.

Sources

All checked on 1 November 2026: the ITF's 2026 Rules of Tennis, Rules 12 to 26 and 29 and Appendix VI. Price figures are from the 77 Tennis win-chance model. Tournaments and tours can add their own regulations on top of the Rules of Tennis, so where a competition's rulebook says something different, that rulebook wins for that competition.

FAQ

Is the ball in if it touches the line?

Yes. Rule 12 of the ITF Rules of Tennis says a ball that touches a line counts as touching the court bounded by that line.

What happens if a serve hits the net?

If it hits the net and lands in the correct service box, it's a let and the server serves again. A let doesn't cancel a fault, so a let on a second serve is still a second serve.

What is a foot fault in tennis?

A fault for the server's feet: touching the baseline or the court, walking or running, or stepping outside the imaginary extensions of the sideline or centre mark during the serve.

Can a player touch the net?

Not while the ball is in play. Touching the net, the net posts or the opponent's court loses the point under Rule 24.

How long can a player take between points?

Up to 25 seconds under Rule 29, counted from the end of one point to the first serve of the next.