The top two in each group will qualify for the round of 16, but how are the teams separated in the table? This is how it works.
1. Group points
This is the easy one. Teams are first ordered by total points from their three matches. It's 3 points for a win, 1 points for a draw and zero for a defeat.
2. Group goal difference
Unlike in UEFA competitions like the Champions League, head-to-head record isn't the next tiebreaker. It's just basic group goal difference -- the net total of goals scored minus goals conceded.
3. Group goals scored
If goal difference is the same, the team with the most goals scored in the group stage will be ranked highest.
This is where it starts to get a little more complicated.
4. Head-to-head record
If teams have an identical group record for points, goal difference and goals scored, we move on to head to head to separate them.
If two teams identical
This is simple, as you look at the result of that one group game. Did one of two teams win that match? If so, they will be ranked highest. If it was a draw, we move directly on to point 5 to split them.
If three teams identical
This is more complicated, as you can't just use individual results because there's three matches to take into account. Effectively, you create a mini-league of just the three games involving the three nations.
This mini league is ranked by
4b) goal difference
4c) goals scored
If only two teams are still level at the end of this stage, direct head-to-head is not applied and these two teams alone move to point 5. The third team is now locked in position.
If all three teams are still level, the order is decided by point 5.
If all four teams identical
It won't be possible to separate them on head to head and the group would be decided on point 5.
5. Fair play record
If any teams still have an identical record after the head-to-head stage, positions are decided by fair play record.
- yellow card: minus 1 point
- indirect red card: minus 3 points
- direct red card: minus 4 points
- yellow card and direct red card: minus 5 points
Only one of the above deductions is applied to a player in one match.
The team with the most points is ranked highest.
The only time fair play record has been needed to separate teams came at the 2018 World Cup.
6. Drawing of lots
If it's still level after fair play points are tallied, the only step left is drawing of lots.
Basically, this is a random draw made by a member of the World Cup organising committee who isn't from one of the countries. It would be a public draw, with two balls placed into a pot. The first team drawn out will be the highest ranked.
This was needed at the 1990 World Cup, with fair play not introduced as a tiebreaker until after the 2014 edition.
Republic of Ireland (2nd) and Netherlands (3rd) finished with identical records and a draw was needed to decide group position -- though both countries had qualified for the round of 16.
Drawing of lots could take place for any of the key positions, including who finishes first and second to determine the path of the knockout bracket.