When must I order uncontested scrums?

Question

Accepted Answer

Under World Rugby Laws 2026 (Law 3):

Scrums become uncontested if either team cannot field a suitably trained front row, or if you so order.
A match organiser may stipulate the conditions under which a game may start with uncontested scrums.
Uncontested scrums as a result of a sending off, yellow card or injury must be played with eight players per side.
When a front-row player leaves the playing area (injury, yellow or red card), you ask at the next scrum whether the team can continue with contested scrums. If told they cannot, you order uncontested scrums. If that player returns or another front-row player comes on, contested scrums may resume.
Only when no replacement front-row player is available may any other player play in the front row.
It is each team's responsibility to make sure its front-row players and front-row replacements are suitably trained and experienced.
Before the match, each team must tell you its front-row players and possible front-row replacements, and which front-row positions they can play. Only those players may play in the front row when the scrum is contested, and only in their designated positions.
In elite rugby, or at the match organiser's discretion, a player whose departure caused uncontested scrums cannot be replaced.