The ARL Commission (ARLC) has ratified the introduction of extra-time in all finals matches.
Two five-minute extra-time periods will be played if scores are level at fulltime. If scores remain locked after extra-time, games will go to golden point.
The ARLC ratified the changes after strong support from clubs, NRL chief Todd Greenberg says.
"The stakes are clearly high in finals series matches, and especially in the grand final, so it makes sense to have a period of extra-time prior to golden point," Greenberg said on Friday in a statement.
"There were a number of alternatives considered but the consensus, by and large, was that the game should introduce extra-time ... not only will it mean a more-expansive style of football in the extra-time period, it will also be less likely that a team is eliminated in golden point."