Sixteen nations will be involved in the Euro 2020 play-offs, competing for the final four qualifying spots for next summer's tournament. It's complicated, but here's all you need to know...
Scotland, Northern Ireland and Wales are currently set to compete in the play-offs, while Republic of Ireland may also have to rely on new format.
Here, we break down the situations, permutations and complications of the Euro 2020 play-off format...
How to do the play-offs work?
Sixteen nations will be involved in the play-offs, competing for the final four qualifying spots for the Euro 2020 finals.
Teams who have not automatically qualified for Euro 2020 will be selected and positioned in a play-off Path - A, B, C, D - based on their performance in the UEFA Nations League (position in group, points, goal difference, goals scored etc)
Nations League group winners automatically qualify for the play-offs but, if they have already qualified for Euro 2020 via the European Qualifiers group stage, their spot in the play-offs will go to the next best-ranked team in their Nations League.
If, for example, League A is unable to send four teams through to play-off Path A, the next best-ranked side from League B will move into League A's play-off Path.
Group winners cannot be placed in a play-off Path with teams from a higher League. Should a play-off Path include at least one group winner and not have enough teams from the same League, the remaining spots will be allocated by lower League teams.
UEFA rankings after 18/19 Nations League
What's the play-off format?
The play-offs are played in single-leg knockout matches. The winners of the two semi-finals will meet in a one-off final where the winner will qualify for Euro 2020.
If the matches are level after 90 minutes, extra time and penalties will be used to determine a winner.
Who plays who in the play-offs?
In a similar format to the EFL play-offs, the highest-ranked team in each Path will host the fourth-ranked team in one semi-final, with the second-ranked nation hosting the third-ranked nation in the other.
The host for the final in each play-off Path will be drawn in advance by UEFA on November 22, 2019.
When will the play-offs take place?
The European Qualifiers play-off semi-finals will be held on March 26, 2020 (7.45pm GMT), with the play-off finals taking place on March 31 (7.45pm BST).
Who's on course for automatic qualification to Euro 2020?
Twenty of the teams listed above will qualify for Euro 2020 through the European Qualifiers. The nations currently occupying these qualification positions are as follows;
Who's heading for the play-offs?
From the remaining nations, the four highest-ranked in each Path will contest the play-offs for a place at Euro 2020.
As things stand, the following nations would qualify for the play-offs (teams in bold are confirmed)
* The current European Qualifiers standings mean a draw would be needed to decide which of Bulgaria, Israel or Romania would fill the vacant spot in Path C, and which two would complete Path A
What does this mean for the Home Nations?
Scotland's hopes of qualifying for Euro 2020 via the conventional route may be over, but they have the insurance policy of a Nations League play-off spot already secured.
Scotland finished top of Nations League C1, guaranteeing their place in the play-offs and a home semi-final as a highest-ranked nation. As things stand, that would mean a tie against Bulgaria, Israel or Romania at Hampden Park on March 26.
Wales and Northern Ireland are currently set for a play-off spot in Path B. Wales would host Slovakia and Northern Ireland would have to travel to Bosnia and Herzegovina, setting up the prospect of both nations meeting in a play-off final were they to navigate the semi-final.
There's an incredibly slim chance of Northern Ireland not making the play-offs at all, though Norway, Romania, Serbia, Finland, Israel, Hungary, Kosovo and Armenia would all have to qualify via the European Qualifiers.