Everything is on the line, but by the end of the day, there will be winners - and losers. The mood of entire nations will be dramatically altered as a result.
World Cup 2010 is a tournament which has already offered the unthinkable. France, one of the world's soccer powerhouses in recent years, lost to host country South Africa on Tuesday. Their hopes dashed, their dream over, they're headed home.
It was a terrible time for France, whose team was torn apart by personality clashes on the practice field, overshadowed only by the disastrous performance on the playing field.
The French coach, who was already leaving, was incredibly ungracious in defeat - refusing even to shake hands with his counterpart.
The U.S. team - which has tied both its games so far - can still move on to the next stage, but it depends on how they perform today, and what their rivals in Group C do, too.
"You work so hard and train for so long for the world cup and it can be over so quickly if you don't advance," notes U.S. team captain Carlos Bocanegra.
But it is the English fans that will be following every kick with their hearts in the mouths. Great expectations have been met thus far with only mediocre performance; two tied games, one with the U.S., one with Algeria.
"Embarrassed," said one England fan bluntly. "I think it's embarrassing that we can't beat the U.S.A., can't beat Algeria, and that now we've got to hope that we can win against Slovenia."
Only a win today will keep the smiles on the player's faces. Lose, and they may as well not even come home.
Depending on today's game results, who goes on and who goes home could actually be determined by pulling names out of a hat. That will determine the "winner" if both England and the U.S.A. tie in their respective games, and both teams score an equal number of goals.
To quote an old line, today's games are not a matter of life and death. They're more important than that.