A legal racket has one flat, uniform string bed within fixed maximum dimensions.

The ruleset and date used here

This page applies the ITF Rules of Tennis 2026, the international baseline in force for the 2026 calendar year, especially Rule 4 and Appendices II and III. It also uses Rules 24 and 29–31 where equipment affects a live point, continuous play or player-analysis data.

The ITF's separate 2026 amendment notice changes Rule 18, Rule 27 and Appendix V, but not Rule 4, Appendix II or Appendix III. ATP and USTA examples below are labelled because their competition procedures supplement the ITF baseline. A club, league, school, national association or tournament may publish different additional requirements.

How to decide whether equipment is legal

1. Name the ruleset. Start with ITF 2026, then check the event's regulations and notices.
2. Measure the racket. Check the overall frame and the hitting-surface limits.
3. Inspect the string bed. There must be one flat, crossed, generally uniform pattern with identical playing characteristics on both faces.
4. Classify every attachment. Ask whether it is approved player-analysis technology or is reasonably sized and placed for wear, vibration or frame-weight distribution.
5. Check when it is used. A legal sensor may collect data without giving the player unrestricted access to it, and a legal racket can still cause a lost point if used illegally.
6. Apply the event procedure. Broken strings, clothing, footwear, delay and sanctions are not identical in every competition.

Four maximum measurements control racket size

ITF 2026 Appendix II(c) says SI measurements take precedence. The racket may not exceed 73.7 cm (29.0 in) overall length or 31.7 cm (12.5 in) overall width. The hitting surface may not exceed 39.4 cm (15.5 in) in length, measured parallel to the handle's longitudinal axis, or 29.2 cm (11.5 in) in width, measured perpendicular to that axis.

Appendix II does not set a general minimum racket weight, minimum head size, grip size, balance point, string tension or approved list of frame materials. Those are equipment choices unless a design fails another part of the rule or an event imposes a separate requirement.

One string bed, flat and generally uniform

Appendix II(b) defines the hitting surface as the main stringing area bordered by the string-entry or string-contact points on the head, whichever boundary is smaller. It must contain one pattern of crossed strings, alternately interlaced or bonded at the crossings. ITF Rule 4, Cases 1 and 2, reject multiple string patterns and strings arranged on more than one plane.

“Generally uniform” does not mean every square must be mathematically identical. It does mean the pattern cannot be less dense in the centre than elsewhere, and both faces must have identical playing characteristics. Different string materials, gauges, tensions and hybrid combinations are not separately banned, but the finished string bed still has to pass those structural tests.

A vibration dampener must sit outside the crossed-string pattern

ITF Rule 4, Case 3, expressly permits vibration-damping devices, but only outside the pattern of crossed strings. A dampener may therefore touch strings beyond the outermost crosses; placing it within the active crossed-string pattern is not legal merely because the product is small.

Appendix II(d) also requires every permitted object to be reasonable in size and placement for its purpose. The rule does not prescribe a brand, shape or number of dampeners, so legality turns on location, purpose and reasonable placement rather than on a universal “one dampener” limit.

Wear protection and frame weighting are permitted purposes

Appendix II(d) permits reasonable objects, protrusions and devices used to limit or prevent wear and tear or vibration. It also permits weight-distribution additions to the frame only. This is the basis for ordinary protective guards, grips, string-wear devices and properly placed frame-weighting tape, provided each addition remains reasonable for its stated purpose.

The limit is functional. An attachment must not make it possible to alter materially the racket's shape, moment of inertia or another performance-related physical property during a point. Nor may an energy source that could affect playing characteristics be built into or attached to the racket. ITF Rule 4, Case 6, gives a battery, solar cell or similar device as the prohibited type of energy source when it affects play.

Approval and access are separate questions

ITF Rule 31 and Appendix III call equipment that records, stores, transmits, analyses or communicates player-performance information Player Analysis Technology (PAT). A smart racket, wearable or other PAT product is not automatically legal: for tournament use under the Rules of Tennis, the product must appear on the ITF's current approved-PAT list.

Approved PAT may record or store information during the match. The player may access that information only in accordance with Rule 30: at times when the sanctioning body permits coaching and expressly permits PAT access. Coaching and PAT access are never permitted while a point is being played. A device's approval therefore does not create a right to read live data whenever the player chooses.

The ITF baseline allows another point—but an event may forbid it

ITF Rule 4, Case 4, says a player who accidentally breaks the strings during a point may continue to play another point with that racket, except where the event organiser specifically prohibits it. The break does not create a let: the current point continues unless some other rule ends it.

This is a genuine competition variation. The ATP 2026 Rulebook, Section VII.T, allows a player to finish the point but not to start a new point with broken strings. If the player's last usable racket has broken strings, ATP applies its unreasonable-delay penalties rather than allowing continued play with that racket. The USTA 2026 Friend at Court, The Code 45, allows a player to leave the court for a replacement racket but makes that player subject to Point Penalty System delay violations.

Changing rackets is legal; using two at once is not

A player may change to another legal racket between points. ITF Rule 4, Case 5, prohibits using more than one racket at any time during play; it does not require one racket for the whole match.

During a point, ITF Rule 24 adds separate use rules. The player loses the point if the ball touches a racket the player is not holding, if the racket touches the net or opponent's court while the ball is live, or if the player deliberately and materially changes the racket's shape while the ball is in play. Equipment legality and stroke legality are therefore different questions.

A racket failure does not earn an ITF equipment timeout

ITF Rule 29(b) may allow reasonable extra time when clothing, footwear or necessary equipment breaks for reasons outside the player's control—but it expressly excludes the racket. A player must normally change rackets within the applicable between-point or changeover time unless the competition's procedure provides otherwise.

That is why regripping, straightening strings or searching for another racket can become delay rather than equipment-repair time. By contrast, a shoe or essential item that genuinely breaks outside the player's control may qualify for reasonable extra time under the ITF baseline.

There is no single worldwide player dress code

The ITF Rules of Tennis do not prescribe a universal colour, logo allowance or shoe sole for every tennis match. Rule 29 deals with time to correct a clothing or footwear failure; the substantive dress and shoe standards normally come from the sanctioning body and event regulations.

For example, the ATP 2026 Rulebook, Section VIII.L.1, requires professional, clean and customarily acceptable tennis attire at ATP Tour and Challenger events. It also gives the Supervisor authority over damaging or unsuitable shoes and adds surface-specific clay and grass provisions. Those ATP requirements should not be presented as automatic rules for WTA, Grand Slam, USTA, school or club tennis.

Junior racket lengths are recommendations, not Appendix II maxima

ITF 2026 Appendix VIII pairs its staged balls and courts with recommended racket lengths: up to 23 in (58.4 cm) for Red; 23–25 in (58.4–63.5 cm) for Orange; and 25–26 in (63.5–66.0 cm) for advanced Green players aged nine to ten.

These are age-and-stage recommendations within the 10-and-under provisions. They do not replace Appendix II's general 73.7 cm maximum with a universal junior equipment offence. A national association or event may make its own age-group equipment requirements, so the competition information still matters.

The ITF decides uncertain racket and technology designs

Under Rule 4, the ITF may rule on its own initiative or on a bona fide application whether a racket or prototype complies with Appendix II. Appendix XII sets the review-and-hearing process, and the current rules remain in force until a ruling is issued; an interim ruling may restrain use of disputed equipment.

There is no general ITF rule saying every ordinary match begins with a measured racket inspection, nor does Rule 4 assign one automatic retrospective score correction for every equipment dispute. The event's official and competition code control the immediate procedure. A player in doubt should seek a ruling before using an unusual design rather than assume that commercial sale proves approval.

The dampener is between two central crosses

Situation: a player clips a small vibration dampener inside the crossed-string pattern.

ITF 2026 ruling: the placement is illegal under Rule 4, Case 3. The device's small size and vibration purpose do not cure its position; it must be moved outside the crossed-string pattern before that configuration is used.

A string breaks, but the local event has no prohibition

Situation: a string breaks during a rally. The player completes the point and is ready to serve the next point with the same racket.

ITF 2026 ruling: Rule 4, Case 4, permits the player to continue for another point because the event organiser has not prohibited it. The opponent is not entitled to replay the completed point merely because a string broke.

The same broken-string facts occur on the ATP Tour

Situation: an ATP player finishes a point after breaking the strings and has no other usable racket ready.

ATP 2026 ruling: the player may not start the next point with the broken strings. Section VII.T directs the ATP unreasonable-delay process if the player's last racket is unusable. This is stricter than the default option in ITF Rule 4, Case 4.

An approved sensor sends data during the match

Situation: an approved PAT sensor records stroke data. Between points, the player opens the data on a device even though the event has not permitted PAT access.

ITF 2026 ruling: recording or storing is allowed, but access is not. Rules 30–31 and Appendix III require the sanctioning body to permit both coaching and PAT access at that time. Access would also be forbidden during the playing of a point in every case.

A dampener comes loose during an ATP point

Situation: a legal dampener flies from the racket and touches the net while the ball remains in play.

ATP 2026 ruling: the player loses the point. ATP Section VII.T treats the dampener as part of the racket for this purpose; under ITF Rule 24(g), the racket touching the net while the ball is live loses the point. If the dampener is discovered only after the point and the official cannot establish when it fell, the ATP case says the point stands.

Claims the rules do not support

• “A broken string always makes the next point illegal.” Not under the ITF default; an event must specifically prohibit it. ATP does.
• “A dampener can go anywhere because it does not strike the ball.” ITF Rule 4 limits it to outside the crossed-string pattern.
• “Every smart racket is banned.” Approved PAT may be used, but approval, data collection and player access are separate tests.
• “The ITF specifies a legal string tension and racket weight.” Appendix II sets no general numeric limits for either.
• “Professional clothing and shoe rules apply to all tennis.” Those are competition regulations; identify the tour or event before applying them.
• “If a racket is sold in a shop, it must be ITF-approved.” Commercial availability is not the formal Rule 4 approval test.

Governing-body sources and effective versions

• International Tennis Federation — Rules of Tennis 2026, Rules 4, 24 and 29–31; Appendices II–IV, VIII and XII
• International Tennis Federation — 2026 Amendments to the Rules of Tennis and Beach Tennis
• International Tennis Federation — current Approved Player Analysis Technology products
• International Tennis Federation — Player Analysis Technology Approval Procedures, revision 8, January 2026
• ATP — 2026 Rulebook, Sections VII.P and VII.T (equipment procedure) and VIII.L (dress and equipment)
• USTA — Friend at Court 2026, The Code 45 and USTA Regulation IV.C.5

Checked on 28 August 2026 against the ITF 2026 rulebook, its published 2026 amendment notice and the current ITF approved-PAT material. The international racket standard is the baseline; the named ATP and USTA provisions demonstrate competition-specific broken-string, delay, clothing and shoe procedures. Other sanctioning bodies and individual events may supplement the baseline.