Comparison of American football and rugby union
A rugby union game is divided into two halves of 40 minutes (or shorter for lower-grade games, and breaks given halfway through each half if playing conditions are considered to be extreme) separated by a half time period of up to 15 minutes in an international match. Most notably, a rugby union game will continue after the scheduled end of a half (half-time or full-time) until the ball becomes dead - any occurrence that would have play restart with a scrum or lineout, or when a team scores. This has led to some "nail-biting" finishes where teams losing by only a small margin work their way towards scoring, and games can go on several minutes over time. Something similar can occur at the end of either half in American football, though usually for only a few seconds of additional time, because a play that begins before the half expires continues until the ball is dead regardless of whether there is any time left on the clock. In both sports, the clock is also stopped during substitutions and for injuries, so the referee does not need to add stoppage time as is done in soccer/Association football. American football games are made up of four quarters of 15 minutes each (less at the high school and youth levels), but the clock stops and starts according to specific rules, so that a 15-minute quarter lasts much longer.
National Academic League
In second quarter, five members of the buzzer team work as a team to answer lengthy questions. There is a back row of five reserve players, but this reserve used only at the discretion of the team coach, who can substitute any or all backup players for any or all active players. This quarter lasts ten minutes with 60 seconds (maximum) for each question. The questions are printed on a card, which is carried to the team by a player of the opposite team, the "runner". When the judge says "Drop", each runner drops the card down on the table. The time starts when the judge reads the question aloud. Players are allowed to talk with each other and write down answers, and collaborate. Although communication is a prime skill in second quarter, no other team member may speak after the captain has buzzed in. Each correct answer is worth three points.