In other changes, two new balls will be used for WNCL matches, CA has introduced a heat policy for all their matches, runners may be used for injured batters at the fall of the ninth wicket and a ball hit on the full and lodged in a fielders' helmet is deemed a catch.
CA wants states to play more attacking cricket in the Shield final in keeping with how the rest of the competition is played.
"The previous rule allowing the home team to win the final in the case of a draw was not consistent with how this competition is generally played," CA's head of cricket operations Peter Roach said.
"In the past six seasons, we have had only two results in the five-day final – 33 per cent – compared to a 79 per cent win-rate in the four-day home and away matches.
"The rule will be trialled this year, and we believe it will encourage the teams involved to push for a result and improve the spectacle in the tournament's showcase match."