27 teams (European national domestic league champions only) playing knock-out rounds on a home and away basis. The aggregate score of both games decides the winner.
The eight remaining teams after the knock-out rounds enter a 1/4 Final Group Stage, played as a round-robin. The final standing is based on individual wins and defeats. In case of a tie between two or more teams after this group stage, the following criteria is used to decide the final classification: 1) number of wins in one-to-one games between the teams; 2) basket average between the teams; 3) general basket average within the group.
The top four teams after the 1/4 Final Group Stage qualify for the Final Stage (Final Four), played at a predetermined venue.