Decision path
Check the item, the action, and the competition conditions
- Identify the R&A and USGA Equipment Rule or playing Rule that applies to the club, ball, device, clothing, or other item.
- Check the competition's Local Rules for restrictions such as the conforming-ball list, one-ball condition, 46-inch club limit, or a ban on distance-measuring devices.
- For clubs, count everything being carried by or for the player and establish whether a club was added, shared, lost, damaged, or adjusted.
- For a ball, distinguish changing it when a Rule permits substitution from simply lifting and replacing the same ball.
- For a device, ask what information or physical help the player actually used—not merely what the device was capable of providing.
- Before making a stroke with doubtful equipment, stop and request a Committee ruling; several equipment breaches carry disqualification once a stroke is made.
Two rulebooks
Conformity and on-course use are separate questions
The Equipment Rules contain the design and performance specifications for clubs, balls, tees, gloves, devices, and other equipment. Rule 4 of the Rules of Golf then tells the player which conforming clubs and balls may be used and how equipment may be used during a round.
A conforming product can still be used illegally. A legal rangefinder becomes a problem if its slope function is used to calculate an adjusted playing distance, and a conforming adjustable driver cannot be deliberately reset and then used during the round. Conversely, carrying a device with a prohibited feature is not automatically a breach if the feature is not used, subject to any stricter Local Rule.
Conforming clubs
The whole club must meet the Equipment Rules
Rule 4.1a requires a conforming club for every stroke. The Equipment Rules regulate the club's general form and components, including its length, grip, shaft, clubhead, face, grooves, spring effect, and external attachments. Except for putters, the standard maximum club length is 48 inches; an optional Local Rule can reduce that maximum to 46 inches.
The player is responsible for conformity. A familiar model name is useful evidence, but it does not excuse a non-conforming individual modification such as sharpened grooves, an impermissible face attachment, or a deliberately changed head. Normal wear does not turn a club that conformed when new into a non-conforming club under Rule 4.1a, although deliberate alteration and damage are treated differently.
Club selection
Any mix is allowed within the 14-club limit
A player may start with fewer than 14 clubs, but not more than 14. There is no rule requiring a driver, putter, wedge, or matched set: 14 putters, two drivers, left- and right-handed clubs, or any other combination is allowed if every club conforms.
All clubs carried by or for the player count. Players may keep their sets in one shared bag, but each player's clubs should be identifiable and sharing the bag does not permit sharing the clubs. A club accidentally placed in the bag without the player's knowledge, or another player's abandoned club picked up after the round starts, is not treated as one of the player's clubs—but the player must not use it. Separate parts of a broken club carried at the start do not count as clubs.
Extra clubs
An excess club must be taken out of play immediately
When a player discovers more than 14 clubs, Rule 4.1c requires a clear action before the next stroke. The player may declare the club out of play to the opponent in match play or to the marker or another player in the stroke-play group. Turning it upside down in the bag, placing it on the floor of a cart, or giving it to another person can also make the status clear.
The club does not need to disappear from the course, but it must not be used again. In match play the Rule 4.1b penalty adjusts the match score by one hole for each affected hole, to a maximum of two holes. In stroke play it is two strokes for each affected hole, to a maximum of four strokes. Making a later stroke with a club already taken out of play brings disqualification.
Adding and sharing
Starting short of 14 does not allow unrestricted borrowing
A player who starts with fewer than 14 may add clubs until reaching 14, provided doing so does not unreasonably delay play. The player may not add or borrow a club being carried by or for another player on the course, and may not build a club from parts being carried by or for any such player.
Players generally cannot make strokes with each other's clubs, even if they are in different groups. The limited partner exception applies in foursomes and four-ball: partners may share clubs only when the total number they have between them is no more than 14. Merely carrying two players' clubs in one bag does not create that permission.
Damaged clubs
A club damaged during the round normally remains usable
If a conforming club is damaged during the round, it is treated as conforming for the rest of that round regardless of the nature or cause of the damage. The player may continue using it. Unless the damage resulted from abuse, the player may instead repair it or replace it, subject to the restrictions on delay, borrowing, building from carried parts, and taking the replaced club out of play.
A club damaged in anger may therefore still be used, but it may not be repaired or replaced under this permission. A lost club is not a damaged club: a player who started with 14 clubs, or added clubs to reach 14, may not replace one that is lost. A stroke-play play-off is a new round, so the special treatment of a damaged club does not automatically carry into it.
Adjustable clubs
Do not change loft, lie, weighting, or performance mid-round
A player must not make a stroke with a club after deliberately changing its playing characteristics during the round. That includes changing an adjustable setting, physically altering the club, or applying a substance to the clubhead to affect its performance. Cleaning the clubhead is allowed.
If an adjustable feature was moved but the club has not yet been used, the player may restore it as nearly as possible to its original setting and use it without penalty. A non-permissible external attachment may likewise be removed before the stroke. Merely carrying an altered or non-conforming club does not breach Rule 4.1a, but it counts toward 14; making a stroke with it brings disqualification.
Golf balls
Every stroke must be made with a conforming ball
Rule 4.2a requires a ball that meets the Equipment Rules for size, weight, spherical symmetry, initial velocity, and overall distance. A player may obtain a conforming ball from anyone, including another player. A ball does not have to be on the current monthly conforming list unless the Committee has adopted Model Local Rule G-3, but a ball known to be non-conforming or obviously designed outside the specifications must not be used.
A player must not deliberately change a ball's performance by scuffing it, heating it, or applying a substance other than in cleaning it. An ordinary identification mark made with a felt-tip pen is allowed. Making a stroke with a non-conforming or deliberately altered ball brings disqualification.
Changing balls
A new hole or an authorised substitution permits a different ball
The player may start every hole with a different conforming ball. During a hole, the normal Rule 6.3a principle is to hole out with the ball played from the teeing area. A different ball may be substituted whenever a Rule allows or requires it—for example, when taking free relief, penalty relief, or stroke-and-distance relief.
When a ball is lifted only so it can be replaced, the original ball normally must go back. Marking and lifting a ball on the putting green does not by itself permit a “putting ball.” If the player substitutes when not allowed and makes a stroke, Rule 6.3b normally adds one penalty stroke; the substituted ball becomes the ball in play, and a wrong-place penalty can apply instead if it was played from a wrong place.
Ball damage
A scratch is not the same as a cut or crack
If a player reasonably believes the ball became cut or cracked during the hole, the player may mark its spot and lift it to inspect it. Away from the putting green, it must not be cleaned during that inspection. Another ball may be substituted only when the damage is clearly a cut or crack that happened on the hole; a scrape, scratch, paint chip, or discolouration is not enough.
If the ball is not cut or cracked, the same ball must be replaced. If a stroke causes the ball to break into pieces, the stroke does not count and there is no penalty; another ball must be played from where that stroke was made. This rare broken-ball procedure is different from a merely cut cover discovered after the shot.
Distance devices
Distance is allowed; adjusted playing advice is not
Rule 4.3 allows a player to get distance or directional information from a rangefinder, GPS device, compass, yardage book, or similar source. It does not allow the player to measure elevation changes or use the device to interpret the information—for example, by producing a “plays like” distance, recommended line, or club selection based on the ball's location.
A multi-function device is not automatically illegal because it contains a slope or club-recommendation feature; the player must not use the prohibited function. The Committee may adopt Model Local Rule G-5 to ban electronic distance-measuring devices entirely, so a device allowed in an ordinary club round may be prohibited in a particular competition.
Other information
Forecasts and old notes are treated differently from live analysis
A player may consult weather forecasts, including forecast wind speed, and may measure temperature or humidity at the course. The player must not measure wind speed at the course or use an artificial object such as powder, ribbon, or a handkerchief to test wind direction. Observing natural indicators such as trees, grass, or the feel of the wind remains part of the player's judgment.
Information gathered before the round—previous-round notes, swing tips, or club recommendations—may be used. A player may record current-round distances, statistics, or heart rate for later use, but must not process current-round playing information into recommendations or use physiological data recorded during the round.
Aids, audio, and grip
Ordinary use is allowed; artificial assistance is limited
- Training aids: an alignment rod, weighted headcover, swing aid, or non-conforming club must not be used to help with swing plane, grip, alignment, ball position, or posture. General stretching is allowed, but not a practice swing with the stretching device.
- Audio and video: unrelated content or background music is normally allowed with consideration for others. Audio used to block distractions or set swing tempo, and video used to help choose a club or play a shot in the current competition, are prohibited.
- Gloves and gripping agents: a conforming plain glove, resin, drying or moisturising agents, and a towel wrapped around the grip are allowed. Equipment that gives an unfair advantage in hand position or grip pressure is not.
- Alignment: a club or other object must not be set down to help take a stance. A player may place a held clubhead behind the ball and walk into the stance while continuing to hold it.
Medical use
A genuine medical need can support a limited exception
Rule 4.3b allows equipment used for a medical condition when the player has a medical reason and the Committee decides that the use creates no unfair advantage. Tape or a similar covering may prevent or assist an injury, but it must not be excessive or provide more help than the medical reason requires.
Rule 25 supplies further modifications for eligible players with disabilities, including provisions for prosthetic devices and assistive mobility devices. A player should raise a doubtful item or method with the Committee before the round; the medical exception is not a blanket permission to disregard equipment specifications or competition conditions.
Local Rules
Elite events can impose stricter equipment conditions
- G-1: a driver used for a stroke must have its model and loft on the current List of Conforming Driver Heads, with the stated pre-1999 exception.
- G-2: clubs used for strokes must meet the groove and punch-mark specifications that took effect in 2010.
- G-3: every ball used for a stroke must appear on the current List of Conforming Golf Balls.
- G-4: the “one-ball rule” requires the same brand and model as a single list entry throughout the round; it does not mean the same physical ball.
- G-5: electronic distance-measuring devices are prohibited even though Rule 4.3 ordinarily permits basic distance information.
- G-9: replacement is limited to a broken or significantly damaged club, not damage of any degree, and the replacement must preserve the progression of the set.
- G-10: a club other than a putter used for a stroke must not exceed 46 inches, with the specified measurement tolerance.
G-1, G-2, G-3, G-4, and G-10 are recommended only for competitions involving highly skilled players. None applies merely because it is common on a professional tour; the Committee must adopt it for the competition.
Worked examples
Small differences change the equipment ruling
- Fifteenth club discovered on the third hole: take an excess club clearly out of play before the next stroke and apply the Rule 4.1b match adjustment or stroke-play penalty, capped at two holes or four strokes.
- Driver shaft snaps during a normal stroke: the player may continue with it, repair it, or replace it under the standard Rule, without unreasonable delay and subject to the adding-and-replacing restrictions.
- Putter bent after being struck against the bag in anger: it may still be used for the rest of the round, but may not be repaired or replaced under the damaged-club permission.
- Adjustable driver changed from 10.5 to 9 degrees: restore it before using it. A stroke made while it remains deliberately changed brings disqualification.
- Rangefinder displays distance and a slope-adjusted number: reading the straight distance is allowed under the standard Rule; using the adjusted number is not.
- Ball is badly scuffed after hitting a path: a scrape alone does not permit substitution under Rule 4.2c, although another Rule may permit substitution if the player takes relief.
Common misunderstandings
Six familiar equipment shortcuts are incomplete
- “Fourteen means a standard full set”: there is no required composition; only conformity and the numerical limit matter.
- “Partners can always share clubs”: the exception applies only in specified partner formats and only when their combined total does not exceed 14.
- “A club broken in anger must be abandoned”: it remains usable for that round, but the player loses the normal right to repair or replace it.
- “You must use one ball for all 18 holes”: changing between holes is allowed, and authorised relief permits substitution. The one-ball Local Rule regulates brand and model, not the physical ball.
- “Rangefinders are always illegal in tournaments”: basic distance and direction are allowed by Rule 4.3 unless Local Rule G-5 prohibits electronic measuring devices.
- “If a device has slope, it cannot be carried”: under the standard Rule the issue is using the prohibited function, although the player must still check the competition's Local Rules.
Officials and penalties
The Committee looks at conformity, knowledge, timing, and use
An equipment ruling begins with facts: the exact model and markings, any modification, when and how damage occurred, how many clubs were carried, what a device displayed, which feature the player used, and which Local Rules were in force. The Committee may use the official equipment databases, inspect the item, and consult The R&A or USGA when conformity cannot be determined on site.
Penalty structures differ. A stroke with a non-conforming or deliberately altered club or ball normally means disqualification. A 14-club, sharing, adding, or replacement breach uses the capped hole or stroke penalties in Rule 4.1b. The first Rule 4.3 improper-use breach brings the general penalty—loss of hole in match play or two strokes in stroke play—and a second breach after an intervening event brings disqualification. A Local Rule may specify its own consequence.
Future standards
A proposed ball-test change does not alter today's ruling
The R&A and USGA announced in June 2026 that there will be no change to the Overall Distance Standard testing approach before January 2030 while they evaluate options with key stakeholders. That review does not make a currently conforming ball illegal under the 2023 playing Rules.
Because the equipment lists and technical standards can change, players preparing for a high-level event should check the current list and competition documents rather than rely on an old package, an earlier list, or a general claim that a model is “tour legal.”
Official references
Source material