The official rules are made by the Badminton World Federation (BWF).
Local rules may also apply.
You can find the latest official rules at the BWF website. Look for the
Laws of Badminton, which they currently hide under
Chapter 4 – Rules of the Game. The other documents (and there’s a lot of them) are irrelevant to most players.
These rules can be hard to understand, because they are written to be
official and comprehensive rather than accessible. But don’t worry! I’ll explain the rules in more
Local by-laws can also apply. For example, let’s say you are playing at a club (or in a tournament) where the courts have many low girders overhead. The club or local badminton association will need to decide how to handle these court conditions: if the shuttle hits a girder, is it a fault or a let?