Badminton — BWF Law 17.5.2 and Statutes Section 4.1.8
A badminton line-call challenge must be immediate.
The BWF Instant Review System checks whether a shuttle landed in or out. On a court where the system is operating, a player or pair may challenge the line judge's decision, an in-or-out call made by the Umpire, or the Umpire's overrule of a line judge. The result can reverse the call, confirm it, or leave the system unable to decide.
Quick ruling: under Badminton World Federation Statutes Section 4.1.8, in force 11 November 2023, Version 2.0, a player or pair keeps challenging until two challenges have failed in that game. A successful challenge, an Umpire-requested review, a “No Decision,” or a system malfunction does not use up a challenge right.
At a glance
How the challenge process works
- A line judge or Umpire makes an in-or-out decision, including an Umpire overrule.
- A player immediately says “Challenge” to the Umpire and/or clearly raises a hand.
- The Umpire checks that the player or pair still has the right to challenge.
- The Umpire identifies the challenger and original call, signals the review request, and the Instant Review System reviews that line call.
- The system returns IN, OUT, or NO DECISION.
- The Umpire announces the resulting decision, updates the score or service as necessary, and resumes play.
Scope
Instant review is available only where the system is operating
BWF Section 4.1.8 begins with a competition-dependent condition: the court must have an Instant Review System in operation. The Laws do not give every player at every tournament a universal right to video review.
A local event without IRS follows its appointed-official procedure instead. A player cannot require an Umpire to consult a broadcast replay, a spectator's phone, or unofficial video. Tournament regulations and the Referee's briefing determine which courts and rounds have the authorised system.
Reviewable decisions
The challenge is for an in-or-out line call
A player or pair may challenge a line judge's call, an in-or-out call made by the Umpire when no line judge decides it, or the Umpire's overrule of a line judge. If a line judge changes the original decision, or the Umpire overrules it, the Umpire must make the players aware and allow an immediate challenge to the changed call.
Section 4.1.8 is not a general replay system for service faults, net contact, double hits, obstruction, misconduct, the score, or service order. Those matters remain with the responsible official and the ordinary appeal process. See badminton officials and line-judge rules for that division of responsibility.
Timing
“Immediately” means before play moves on
BWF Section 4.1.8 requires the challenge immediately after the player observes the call. The current BWF Instructions to Technical Officials, effective 1 July 2026, direct the player to say “Challenge” clearly to the Umpire and/or raise a hand as a clear signal.
The procedure does not provide a deliberation period in which a player can watch a venue screen, consult a coach, or wait to see the score announcement before deciding. A prompt signal lets the Umpire stop the match process before the next rally begins. A late request is not a valid challenge.
Challenge allowance
Two failed challenges end the right for that game
The allowance is not simply “two challenges.” A player or pair may make an unlimited number of challenges until two of them have failed during the game. A failed challenge is one where review confirms that the challenged line call was correct.
The count applies to the player or pair, so doubles partners share it. A successful challenge leaves the right intact. Because the BWF limit is expressed for each game of the match, the failed-challenge count starts again in the next game.
Successful review
An incorrect original call is reversed
If IRS shows that the line judge's or Umpire's original decision was incorrect, the challenge succeeds and that decision is reversed. The Umpire announces “Correction, IN” or “Correction, OUT,” then gives the score or service-over announcement produced by the corrected result.
The rally is not replayed merely because the call was wrong. The corrected in-or-out decision determines who won that rally. If the correction decides the game, the Umpire makes the corresponding game announcement instead of restarting play.
Unsuccessful review
A confirmed call costs one challenge right
If IRS shows that the original in-or-out call was correct, the challenge fails and the original result stands. The Umpire announces that the challenge was unsuccessful and, where play will continue, states whether one or no challenges remain before announcing the score and calling play.
The first failed challenge leaves one further failed challenge available in that game. After the second failed challenge, that player or pair cannot challenge another line call until the next game.
No Decision
No Decision does not automatically reverse the call
If IRS returns NO DECISION on a player's challenge to an existing in-or-out call, the original call remains in force. Neither side loses a challenge right. The system's inability to decide is not evidence that the original official was wrong.
A different result applies when the original report was “unsighted” and the Umpire also could not decide. If the Umpire requests IRS in that situation and the system returns No Decision, the Umpire calls a let. Play since the last service does not count, and the player who served last serves again.
Umpire review
An Umpire-requested review is not a player challenge
When a line judge is unsighted and the Umpire cannot make the line decision, BWF procedure requires the Umpire to ask IRS where it is operating. This is an official request, not a challenge charged to either side.
If IRS returns IN or OUT, the Umpire announces that result and applies it to the rally. If it returns No Decision, the result is a let because there was no underlying in-or-out call capable of standing.
System problems
Malfunction and an obviously wrong display have different procedures
A system malfunction does not cost either player or pair a challenge right. Where the displayed IRS decision is inconsistent—for example, its text conflicts with its graphic—or is obviously incorrect, the Umpire must call the Referee before the next rally.
The Referee instructs the Umpire how to resume play. Players do not settle the contradiction by choosing the image or wording they prefer, and the Umpire should not silently improvise a result.
Worked situations
Count the outcome, not just the request
- First review reverses OUT to IN: the challenge succeeds, the rally result is corrected, and the player still has no failed challenges.
- Next review confirms IN: the challenge fails, the original call stands, and the player has one failed challenge in that game.
- A later review returns No Decision: the existing call stands, but the player's failed-challenge count remains at one.
- The next review reverses another call: it succeeds, so the count still remains at one failed challenge.
- A later review confirms the call: that is the second failed challenge, so no further player challenge is available in that game.
- In doubles: one partner's failed challenge counts for the pair; the partners do not receive separate allowances.
Common mistakes
Misunderstandings to avoid
- “Each player gets two challenges.” In doubles, the pair shares the challenge right.
- “You may challenge only twice.” Successful challenges do not reduce the allowance; the right ends only after two failures in a game.
- “No Decision means replay the rally.” It produces a let only when the original line decision was unsighted. Otherwise the existing call stands.
- “Any officiating call can be reviewed.” BWF Section 4.1.8 covers line calls, not every fault or scoring dispute.
- “A player can wait for the slow-motion screen.” The challenge must be immediate after the call is observed.
- “IRS is available at every BWF-rules match.” The procedure applies only on a court where an authorised system is operating.
- “An Umpire review uses one of the player's challenges.” An official request after an unsighted call is not charged to either side.
Official references
Source material