^Spain (ESP):MoraBanc Andorra is a club based in Andorra (which does not qualify for European competitions), but participate in European competitions through one of the berths for Spain (any coefficient points they earn count toward Spain).
^France (FRA):Monaco are a club based in Monaco (which does not qualify for European competitions), but participated in European competitions through one of the berths for France (any coefficient points they earn count toward France).
The draw was held on 5 July 2018 at the Mediapro Auditorium in Barcelona.
The 24 teams were drawn into four groups of six, with the restriction that teams from the same country could not be drawn against each other. For this purpose, Adriatic League worked as only one country. For the draw, the teams were seeded into six pots, in accordance with the Club Ranking, based on their performance in European competitions during a three-year period and the lowest possible position that any club from that league can occupy in the draw is calculated by adding the results of the worst performing team from each league.
^† Indicates teams with points applying the minimum for the league they play.
The fixtures were decided after the draw, using a computer draw not shown to public, with the following match sequence:
Note: Positions for scheduling do not use the seeding pots, e.g., Team 1 is not necessarily the team from Pot 1 in the draw.
6 v 3, 4 v 2, 5 v 1
1 v 6, 2 v 5, 3 v 4
6 v 4, 5 v 3, 1 v 2
6 v 2, 3 v 1, 4 v 5
5 v 6, 1 v 4, 2 v 3
1 v 5, 2 v 4, 3 v 6
4 v 3, 5 v 2, 6 v 1
2 v 1, 3 v 5, 4 v 6
5 v 4, 1 v 3, 2 v 6
3 v 2, 4 v 1, 6 v 5
There were scheduling restrictions: for example, teams from the same city in general are not scheduled to play at home on the same round (to avoid them playing at home on the same day or on consecutive days, due to logistics and crowd control).
Location of teams of the 2018–19 EuroCup regular season. Red: Group A; Green: Group B; Blue: Group C; Yellow: Group D.
In each group, teams played against each other home-and-away in a round-robin format. The group winners, runners-up, third-placed teams and fourth-placed teams advanced to the Top 16, while the fifth-placed teams and sixth-placed teams were eliminated. The rounds were 2–3 October, 9–10 October, 16–17 October, 23–24 October, 30–31 October, 6–7 November, 13–14 November, 20–21 November, 11–12 December, and 18–19 December 2018.
In each group, teams played against each other home-and-away in a round-robin format. The group winners and runners-up advanced to the Playoffs, while the third-placed teams and fourth-placed teams were eliminated. The rounds were 2–3 January, 8–9 January, 15–16 January, 22–23 January, 29–30 January, and 5–6 February 2019.
In the playoffs, teams play against each other must win two games to win the series. Thus, if one team wins two games before all three games have been played, the game that remains is omitted. The team that finished in the higher Top 16 place will play the first and the third (if it is necessary) legs of the series at home. The playoffs involves the eight teams which qualified as winners and runners-up of each of the four groups in the Top 16.