It is common in youth sports in North America, where running up the score is considered unsporting.
It is especially common in baseball and softball in which there is no game clock and a dominant team could in theory continue an inning endlessly.
Thus, one team, particularly if it is decidedly better than a weaker opponent, can still "run up the score" before the rule takes effect.
In most states, the clock stops only for scores, timeouts (officials', injury, or charged), or the end of the quarter.
The rule varies by state; for example, the clock does not stop upon a score in Colorado, Indiana, Kansas (regular-season games only), or Missouri (fourth quarter only).
Sometimes the coach of the team that is losing agrees to shorten the length of a quarter in addition to the continuous clock rule.
In some states (where 8-man and 6-man football is widely used), the rules call for a game to end when one team is ahead by a certain score (like 45 or 50 points) at halftime or any time thereafter.
The National Collegiate Athletic Association's mercy rule provides, "Any time during the game, the playing time of any remaining period or periods and the intermission between halves may be shortened by mutual agreement of the opposing head coaches and the referee."
"[4] The most recent example of an NCAA football game shortened by invoking this rule occurred on September 13, 2024, when the South Alabama Jaguars played the Northwestern State Demons.
[6] On September 7, 2024, the Georgia Bulldogs led the Tennessee Tech Golden Eagles 45–0 at the end of the third quarter.
[12] Earlier in 2016, the game between Texas State and Arkansas saw the fourth quarter shortened to 10 minutes when severe thunderstorms were approaching Donald W. Reynolds Razorback Stadium.
In a 2013 game, Old Dominion University (ODU) was losing to the University of North Carolina (UNC) 80–20 when ODU coach Bobby Wilder asked for the fourth quarter to be shortened by five minutes, which UNC coach Larry Fedora agreed to.
Fedora also directed his quarterback to take a knee on fourth and goal with 1:53 remaining to not run up the score.
[13] In a 1988 game, Kansas Jayhawks coach Glen Mason asked if a running clock could be used after his team trailed 49–0 at halftime to the Auburn Tigers.
[14] In 2015, another shortened game occurred when the Boston College Eagles dominated the Howard Bison 62–0 by halftime.
[15] However, in the Mississippi Association of Community and Junior Colleges, a running clock is allowed if the team is ahead by 38 points or more.
[16] In U.S. high school soccer, most states use a mercy rule that ends the game if one team is ahead by 10 or more goals at any point from halftime onward.
In regular season or conference tournament NCAA and NAIA college baseball, the IBAF rule may be implemented.
(In either case, if the home team is ahead by the requisite number of runs, the game will end after the top half of the inning.)
By comparison, in Kansas, if the running clock is triggered, it will not stop except for a timeout or an injury even if the differential is reduced to under 30 points.
As with other sports, some states offer provisions to allow a team to end the game early by mutual decision of the coaches (for instance, if a large lead continues to grow and the talent disparity is obvious).
In amateur boxing, if a boxer trails by more than 20 points, the referee stops the fight and the boxer that is leading automatically wins; bouts which end this way may be noted as "RSC" (referee stopped contest) with notations for an outclassed opponent (RSCO), outscored opponent (RSCOS), injury (RSCI) or head injury (RSCH).
Either action can be taken if a team believes it would help them more quickly complete the conditions necessary to win within the time limit (up to five days).