The postseason has arrived for college softball. The road to Oklahoma City for the Women's College World Series officially gets underway Friday, with the first set of games in the NCAA Tournament regional round.

Likely contenders to compete for the national championship in early June include reigning three-time national champion Oklahoma, as well as teams such as Texas, Oklahoma State, Florida State and Tennessee among, others.

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If recent postseason history has shown anything, this year's tournament will once again feature the enforcement of one of the sport's most distinct rules: the run-ahead rule. It allows teams to finish games before the completion of seven innings and has become a widely used rule in recent years.

Here's what you need to know about the run rule in college softball as the 2024 NCAA Softball Tournament and Women's College World Series kick off:

Does college softball have a run rule?

Yes. According to the NCAA, a team must lead by eight or more runs after five or more innings — or, in the case of the home team, 4 1/2 innings — for the run ahead to go into effect. It is informally known as the mercy rule.

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What is the WCWS championship run rule?

The current mercy rule in college softball is eight or more runs after five or more equal innings. The run rule can technically be enforced in the bottom of the fifth inning — so 4 1/2 of actual game being played — if the home team reaches the eight-run mercy rule at any point in the bottom of the fifth. However, if the visiting team reaches the eight-run rule, the home team has the opportunity to score enough points to negate the rule's enforcement.

Per Rule 6.14 of the "2024 and 2025 Softball Rules Book":

"A regulation eight-run-rule game shall be declared by the plate umpire if one team is ahead by eight or more runs after five or more equal innings. Complete innings must be played unless the home team reaches the eight-run lead while at bat in the last inning. Any hit that results in an eight-run lead by the home team (after 4 1/2 innings) is treated as a game-ending hit. (See Rule 14.5.)

"Whenever the visiting team reaches the limit in the fifth or any inning thereafter, the home team must have its opportunity to bat in the bottom half of the inning."

Last year, Oklahoma won four of its 10 games come by the mercy rule against Hofstra, Missouri, Cal and Tennessee en route to the Sooners' third consecutive Women's College World Series title.

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Is there a run rule in the WCWS championship?

Yes. According to the NCAA's 2023-24 pre-championship manual, provided to the USA TODAY Network, there is no change in the run-ahead rule in the NCAA Softball Tournament or the Women's College World Series.

The eight-run rule was in effect for the 2023 WCWS championship series, as reported by the OU Daily in June 2023. It wasn't in effect the year prior, in 2022, when Oklahoma demolished Texas 16-1 in Game 1 of the WCWS championship series.

In other words, if the run-ahead run was to not be enforced it would need to be made aware and public before the start of the three-game championship series.

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This article originally appeared on Oklahoman: College softball run rule for NCAA Tournament, Women's College World Series