A central principle, although not one of the numbered rules, is found in the R&A rule book's inside front cover:
- Play the ball as it lies, play the course as you find it, and if you cannot do either, do what is fair. But to do what is fair, you need to know the Rules of Golf.
In addition to the rules golf adheres to a code of conduct, known as etiquette, which generally means playing the game with due respect for the golf course and other players. Etiquette is often seen as being as important to the sport as the rules themselves.