Badminton — BWF Laws 1.3, 13.3.1, 14.2.6 and 17
If the shuttle touches the active boundary line, it is in.
A badminton line call has two parts: choose the boundary that applies to that shot, then judge where the shuttle lands. Singles, doubles, and service do not always use the same lines. Officials also follow a defined process for close, incorrect, and unsighted calls.
Quick ruling: under Badminton World Federation Laws of Badminton in force 26 April 2025, Version 5.0 (2), every line forms part of the area it defines. A shuttle that lands on or within the relevant boundary is in. It is out only when it lands outside that boundary.
Decision path
Make the call in this order
- Identify whether the match is singles, doubles, or a Para badminton class using a modified court.
- Decide whether the landing is the service or part of the rally after the service has been returned.
- Select the side, front, and rear boundaries that apply to that format and phase.
- Wait for the shuttle to touch the floor or something outside the court.
- Call it in if the landing touches the active line or the area inside it; call it out if the landing is wholly beyond the active boundary.
- If the assigned official was unsighted, use the umpire, Instant Review System, or let procedure rather than guessing.
Core rule
The painted line belongs to the area it marks
BWF Law 1.3 says that all court lines form part of the areas they define. Law 13.3.1 therefore makes a landing a fault only when the shuttle lands outside the court boundaries—not on or within the boundary lines.
The full 40 mm width of the relevant line counts as part of the defined area. There is no separate “too close to call” strip and no requirement that most of the shuttle be inside. Visible contact with the active line is an in landing.
Landing point
Judge the impact, not where the shuttle finishes
The shuttle ceases to be in play when it hits the court surface. BWF line-judge instructions likewise require the official to wait until the shuttle has touched the floor or something outside the court boundaries before signaling.
A shuttle can bounce, tip, or slide after impact. Its later resting position does not relocate the landing. The relevant event is its floor contact, viewed against the active boundary.
Active lines
A visible line is not necessarily the line in use
During a standard singles rally, the inner side lines and full back boundary are active. During a standard doubles rally, the outer side lines and full back boundary are active. A landing in a doubles side alley is consequently out in singles but in during a doubles rally.
Service adds the short service line, centre line, and the format's rear service boundary. For the full measurements and a boundary-by-boundary diagram explanation, see badminton court dimensions and boundary lines.
Service calls
The serve must land in the diagonal service court
An uninterrupted correct serve must be capable of landing on or within the receiver's diagonal service-court boundaries. A serve that first lands on an active short, centre, side, or rear service line is in, assuming the delivery itself was legal.
Singles uses the inner side line and full back boundary for service. Doubles uses the outer side line but the doubles long service line 0.76 m inside the back boundary. The rear strip beyond that inner line is out on a doubles serve and becomes in once the serve has been returned and the normal doubles rally boundaries apply.
Shuttle versus player
Do not catch a shuttle to demonstrate that it was going out
Law 13.3.4 makes it a fault if the shuttle in play touches a player's person or clothing. A player who catches, blocks, or is struck by a shuttle before it lands loses the rally even when the shuttle appeared likely to travel outside the court.
The same principle applies when another fault occurs before the landing. Line judges still report the landing assigned to them without trying to anticipate the umpire's decision about a touch or other earlier fault; the umpire applies the Laws to the full sequence.
Line judges
The assigned line judge owns the initial finding of fact
Under BWF Law 17.4, a line judge indicates whether the shuttle landed in or out on the assigned line or lines. The BWF Instructions to Technical Officials, in force 17 November 2025, Version 8.0, tell a line judge to call “Out” promptly and extend both arms horizontally for an out landing.
For an in landing, the line judge says nothing and points to the line with the right hand while looking toward the umpire. For an unsighted landing, the line judge immediately covers the eyes with both hands. Silence alone should not be read as uncertainty: it is part of the prescribed in-call procedure when paired with the signal.
Umpire control
A line judge's call is final unless a stated exception applies
An official's decision is final on the facts assigned to that official. The umpire does not routinely substitute a different view merely because the landing was close. Under Law 17.5.1, the umpire must overrule only when it is beyond reasonable doubt that the line judge clearly made the wrong call.
The BWF instruction is to correct the call immediately with “Correction, IN” or “Correction, OUT.” Where no line judge is appointed, or the line judge is unsighted, the umpire makes the landing decision if able.
Unsighted calls
If nobody can decide, the rally is replayed as a let
If a line judge is unsighted, the umpire first decides if the umpire has a clear view. Where an Instant Review System is operating and the umpire cannot decide, the system is asked for the decision.
If the line judge is unsighted and neither the umpire nor the review system can determine in or out, BWF Law 14.2.6 requires a let. Play since the last service does not count, and the player who served last serves again. The rule supplies a replay for a genuinely unavailable decision, not for ordinary disagreement with a call that an official did make.
Video challenges
Instant review changes the decision process, not the line rule
On a court using the BWF Instant Review System, a player or pair may immediately challenge a line judge's call, or a call or overrule by the umpire. If the system finds the original decision incorrect, it reverses that decision. A successful challenge does not use up a challenge right.
Under BWF Statutes Section 4.1.8 in force 11 November 2023, Version 2.0, a player or pair may continue challenging until two challenges have failed in that game. An umpire-requested review, a “No Decision,” or a system malfunction does not count as a failed player challenge. Review availability is competition-dependent; it does not change the rule that the active line is in. The full timing, allowance, and outcome procedure is explained in badminton line-call challenges and instant review rules.
Appeals
A disputed fact is different from a disputed rule
A player may appeal a point of dispute to the umpire before the next service is delivered. But a factual finding about where the shuttle landed remains within the line-call process: assigned official, clear-error overrule, and Instant Review System where available.
The umpire refers an unsatisfied appeal to the referee only on a question of law. For example, “the shuttle landed outside” is a factual call; “the doubles long service line was incorrectly treated as the rally boundary after the return” raises which law or boundary applies. The appeal deadline is before the next service, or at match end before the appealing side leaves the court.
No appointed officials
Local procedure fills the self-officiating gap
BWF Law 17 describes matches with appointed technical officials, and directs the umpire to arrange for missing officials' duties to be carried out. It does not provide a complete player line-call code for an informal match with no officials at all.
A club, school, or local tournament may therefore specify who calls each line and how disputes are handled. Players should establish that procedure before play. Those arrangements allocate the decision; they should not reverse the BWF landing standard that the relevant line counts as in.
Worked calls
Apply the active boundary before judging the mark
- Singles rally: the shuttle touches the inner side line. It is in.
- Singles rally: it lands between the inner and outer side lines without touching the inner line. It is out.
- Doubles serve: it touches the doubles long service line. It is in, if the service was otherwise correct.
- Doubles serve: it lands beyond that long service line but before the full back boundary. It is out.
- Doubles rally after the return: the same rear-strip landing is in because the full back boundary now applies.
- Shuttle heading wide: a player catches it before floor contact. The touch is a fault against that player; its predicted landing is irrelevant.
- Unsighted crew: the line judge, umpire, and available review system cannot decide. The result is a let, not an assumed in or out call.
Variations
Modified courts change the boundary, not the line principle
Wheelchair Badminton and the SL3 standing singles class use the modified court areas shown in BWF Diagrams D, E, and F. Other standing classes use the standard Diagram A court. The correct class diagram determines which boundary is active, while Law 1.3 still includes the marking line in the area it defines.
Youth, recreational, and local competitions may authorise reduced courts or additional line-call procedures. Check the governing competition regulations before applying a standard-court diagram to a modified format.
Common mistakes
Misunderstandings to avoid
- “A shuttle touching the line is out” reverses the BWF rule. The active line belongs to the area it defines.
- “Every painted line is active” ignores format and phase. Singles, doubles service, and doubles rally boundaries differ.
- “Doubles is short throughout the rally” confuses the doubles service boundary with the full rally court.
- “The shuttle's final resting place decides” ignores the floor impact that ends play.
- “An umpire may freely change any close call” understates the clear-error threshold for overruling an assigned line judge.
- “Any disagreement produces a let” is wrong. The unsighted let applies when the designated decision-makers cannot make a decision.
- “A player can catch an obviously out shuttle” overlooks the fault for touching the player's person or clothing while it remains in play.
Official references
Source material