Overtime or extra time is an additional period of play specified under the rules of a sport to bring a game to a decision and avoid declaring the match a tie or draw where the scores are the same. In most sports, this extra period is only played if the game is required to have a clear winner, as in single-elimination tournaments where only one team or players can advance to the next round or win the tournament. In other sports, particularly those prominently played in North America where ties are generally disfavored, some form of overtime is employed for all games.
The rules of overtime or extra time vary between sports and even different competitions. Some may employ "sudden death", where the first player or team who scores immediately wins the game. In others, play continues until a specified time has elapsed, and only then is the winner declared. If the contest remains tied after the extra session, depending on the rules, the match may immediately end as a draw, additional periods may be played, or a different tiebreaking procedure such as a penalty shootout may be used instead.
The terms "overtime" and "in overtime" (abbreviated "OT" or "IOT") are primarily used in North America, whereas the terms "extra time" and "after extra time" (abbreviated "a.e.t.") are usually used in other continents. However, in basketball, the terms "overtime" and "in overtime" are used worldwide.
In association football knock-out competitions or competition stages, teams play an extra 30 minutes, called extra time, when the deciding leg (or replay of a tie) has not produced a winner by the end of regulation or full-time. Extra time is governed by the rules of the tournament, rather than the laws of the game. It follows a short break where players remain on or around the field of play and comprises two straight 15-minute periods, with teams changing ends in between.
In a one-off tie or deciding replay, level scores nearly always go to extra time. In games played over two legs (such as the UEFA Champions League or World Cup qualification intercontinental play-offs), teams only play extra time in the second leg where the aggregate score – then normally followed by an away goals rule – has not produced a winner first. Ties in the FA Cup used to be decided by as many replays as necessary until one produces a winner within normal time, rather than have any extra time (and/or shootout), though nowadays replays are limited to just the one, with the second going to extra time if teams are still level. Equally, CONMEBOL has historically never used extra time in any of the competitions it directly organises, such as the Copa Libertadores (today, it uses extra time only in the final match of a competition). The score in games or ties resorting to extra time are often recorded with the abbreviation a.e.t. (after extra time), usually accompanying the earlier score after regulation time.