In or out?

In badminton, the line is in. The lines are part of the area they mark out (BWF Laws of Badminton, Law 1.3), so if any part of the shuttle's base touches the line, it's in. It's only out when it lands completely outside the boundary. What changes is which lines count: singles or doubles, serve or rally.

Badminton in or out on the line

Lines are 40 mm (about 1½ in) wide. A shuttle landing on the outer edge of the line is just as in as one landing in the middle of the court. What counts is where the shuttle first touches the floor: the cork usually lands first, so that's what officials watch. Feathers brushing past the line in the air don't matter.

Badminton lines: in or out by situation

Every line in the table is itself in. The two that confuse people: the side alleys are out for all of singles, and the back alley is out only for the doubles serve. More detail in singles rules and doubles rules.

Call it yourself

Pick a game and a moment, then tap where the shuttle lands. Try the edges: a touch of the line is in, a few millimetres outside it is out.

Badminton line rules: who makes the call?

Casual games

With no officials, convention is that each side calls the lines on its own side of the net, and gives the benefit of the doubt to the opponent. If neither of you saw it clearly, replay the rally: the Laws make it a let when nobody can decide.

Matches with an umpire and line judges

Each line judge watches their assigned line and signals whether the shuttle landed in or out (Law 17.4): by convention, a loud “out” with arms spread wide, a hand pointing at the line for “in”, and hands over the eyes when unsighted. Their decision is final, with two exceptions (Law 17.5):

• The umpire must overrule a line judge if they're sure beyond reasonable doubt the call was clearly wrong.
• Where an instant review system is in use, it decides any challenged line call.

If a line judge is unsighted and the umpire can't decide either, it's a let and the rally is replayed (Law 14).

Hawk-Eye and challenges

At top BWF events, the TV courts usually have an Instant Review System, often just called Hawk-Eye after the best-known camera line-calling system. The BWF's Instant Review System regulations say:

• A player or pair may challenge a line judge's call, or an umpire's call or overrule.
• The challenge must be made immediately after the call.
• Challenges are unlimited until a player or pair has two failed challenges in a game; then they can't challenge again that game.
• A successful challenge doesn't cost anything, and if the system shows “no decision” or the umpire asks for a review, nobody loses a challenge.

Courts without the system, which is most of them, even at big events, run on line judges and the umpire. Why one camera can't replace that, and what multi-camera systems do, is in how line calls work.

Test your eye with the in or out quiz, or see all the court lines measured on the court dimensions page.