A gruelling test of fitness and focus, extra time pushes the world's best players to the limit at the World Cup.
Once the whistle blows for the end of normal time, there's nowhere to hide. The players remain out on the pitch for all to see, gathering around their manager for last-minute instructions and a brief respite.
With the stakes at an all-time high in Qatar, it's guaranteed plenty of the crunch games will go beyond regular time.
Although a nerve-wracking prospect if your favourite team is involved, extra time is where tournaments come alive. The Sporting News gives you the lowdown on what will be a crucial feature at these finals.
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What is extra time in soccer?
Unlike in the Premier League, MLS conferences or La Liga, sharing a draw is not an option on the deciding days and nights of the World Cup.
After the group stages have whittled the contenders down by half, knockout games that complete 90 minutes with a level scoresheet are sent to extra time. The group matches themselves can finish as draws.
Playing additional minutes is a major disadvantage in tournament football but no doubt certain teams will be forced through gruelling extra-time periods more than once in their bid for glory.
With the Qatar World Cup being held midway through the packed European season, the sight of players stricken by cramp will be ever more common.
Rules for extra time and how it works
Up until 2002, World Cups used the Golden Goal rule to determine the winner in extra time, whereby the first team to score in the additional period went through to the next round.
However, in subsequent tournaments — and at Qatar 2022 — extra time is simply an extension of the regular 90 minutes.
If extra time is still not enough to separate two nations, their fate will be decided by a penalty shootout.
Managers are also allowed to make one additional substitution in extra time, even if they have used all of their permitted changes during regulation time.
How long is extra time?
Players are granted just five minutes to catch their breath following the end of the regulation 90 minutes before kicking off again.
The referee will oversee two 15-minute halves with a short break between each.
Additional time can also be added on for injuries or stoppages during extra time, potentially taking the match beyond 120 minutes.
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World Cup extra time
Two of the past three World Cup finals were decided by extra time in dramatic fashion.
After a feisty but goalless night in Johannesburg, South Africa, Andres Iniesta broke Dutch hearts in the 116th minute to clinch the 2010 title for Spain's golden generation.
Four years later it would be Mario Gotze, lunging to nick the ball past Argentina keeper Sergio Romero in the 113th minute for German glory.
Extra time brought pain for USMNT fans back in 2010 when their last-16 clash with Ghana ended level at full-time, only for Asamoah Gyan to strike (below) and send Bob Bradley's team home.