What are my duties before and during a game?

Under law 43 of the Laws of the Sport of Bowls (Crystal Mark 4th edition), the umpire is appointed by or for the Controlling Body and must:

Before the game starts:

• check that all bowls carry a clearly visible, valid World Bowls Stamp;
• measure the rink width to confirm it complies with law 49.1 (Bowls SA recommends at least 5 m where practical);
• measure the pegs, discs or other markers on the side banks to confirm the distances under law 49.12.

During play:

• measure any disputed shot with suitable equipment;
• decide whether the mat line's distance from the ditches, and the jack's or a bowl's distance from the mat line, comply with the laws;
• decide whether a jack or bowl is in play;
• make sure all aspects of play comply with the laws.

Your decision is final except on the meaning or interpretation of a law, which can be appealed to the Controlling Body. Under Bowls SA's footwear regulation, umpires must also wear compliant flat-soled shoes on the green.