The Ground
Defines the dimensions, markings, goal posts, and flag posts of a rugby field.

A rugby field — called "the ground" — must be a safe, rectangular playing surface. It has a field of play (where most of the action happens) plus two in-goal areas at each end where tries are scored. The field is between 94 and 100 metres long and 68 to 70 metres wide. The in-goal zones add another 6 to 22 metres at each end.
The field is marked with solid lines (try lines, 22-metre lines, the halfway line, touchlines) and dashed lines (at 5 metres and 15 metres from touchlines, and 5 metres and 10 metres from each end). The goal posts sit on the try line — 5.6 metres apart with a crossbar 3 metres from the ground. There are 14 flag posts around the pitch to help officials judge touch and in-goal decisions.
If any part of the ground is unsafe, the referee will not start or will halt the match.
Real-World Examples
Scenario
The groundskeeper has left a sprinkler head protruding from the surface near the 22-metre line. A team captain notices it during warm-ups.
Outcome
The captain must inform the referee before the match starts. The referee assesses the hazard and will not begin play until it is made safe, as the playing surface must be safe under Law 1.1.
Scenario
A converted try is kicked from directly in front of the posts. The ball clears the crossbar but passes outside the post (which is only 3.2 metres tall, so the ball is above the top of the post).
Outcome
The kick is successful. Under Law 1 (and Law 8), if the ball goes over the crossbar and over the height of the goal posts, the kick is successful if it is deemed the ball would have gone between the posts had they been taller.
Scenario
A stadium has pitch dimensions of 96 metres long and 69 metres wide for the field of play, with 8-metre in-goal areas.
Outcome
This is legal. The dimensions fall within the permitted range (94–100m length, 68–70m width, 6–22m in-goal). The dash-line distances between the 10-metre lines and 22-metre lines would be reduced proportionally.