For rugby aficionados, the laws of the sport have a poetic beauty. They encourage variety and subtle relationships between phases of play, which demand an immense range of skills and playing styles for competitors of different shapes and sizes.
For less-committed spectators, the sheer complexity of rugby can be an obstacle to comprehension and enjoyment; one that leaves them once again mystified about why the referee’s whistle went, what the player was deemed to have done wrong, and why that particular offence was punished with a penalty kick rather than a put-in at a scrum.

The Business of Rugby Union 