Do not draw the line through the visible ball
Current Law 15 sets each ruck offside line through the hindmost point of a participant, parallel to the try line. That point may extend behind where the ball lies. The ball itself is not a universal substitute for the line.
Imagine the ball visible near the front of a long ruck while a participant’s rear point remains farther towards their own try line. A nearby defender can be behind the ball yet still ahead of the relevant offside line.
Use the full formation in the frame
A close-up of the scrum-half lifting the ball may exclude the rear of the ruck. To interpret an offside call, the wide angle needs to show that rear point and the defending line together.
This helps explain why a television line, when provided, may appear farther back than a viewer expects. It is locating the formation’s boundary rather than tracing the ball’s centre. The example is a positional illustration, not a complete account of exactly when every ruck ends. Keep the line’s reference and the later ball-out question separate so a correct answer to one does not get used as proof of the other.
Questions answered
Is being behind the ball always enough?
No. The ruck’s hindmost-point reference matters.
Which camera framing helps?
One showing the rear of the ruck and the defender together.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.