The stages

The tournament consists of several stages and begins with three preliminary knockout qualifying rounds. Different teams start in different rounds, according to their position in domestic league and the UEFA coefficients of their league, while the sixteen top ranked teams spread across the biggest domestic leagues qualify directly.

In the subsequent preliminary round, participating teams are paired, with aggregate winners proceeding into the next round. Qualifying rounds span from mid-July to late August. The losers of the third qualifying round are transferred to the UEFA Cup, while the sixteen winners of the final qualifying round are joined by the sixteen teams who have qualified directly, to participate in the group stage.

Teams are drawn into eight groups of four teams, each team playing every other team in the group twice (home and away). The group stage is played between mid-September and early December. The teams finishing third in their groups are transferred to the UEFA Cup, while the top two teams from every group qualify for the next round. Here the sixteen remaining teams take part in the knock-out stage, which starts in late February and ends with the final match in May.

All qualifying rounds and knock-out ties are two-legged, with each team hosting one match. The team which scores the greater aggregate number of goals qualifies for the next round. The away goals rule applies. Extra time and penalty kicks are used to determine the winner, if necessary. An exception is the final, which is a single match played at a predetermined venue.

The draws are currently structured to ensure that clubs representing the same national association cannot play each other until the quarter-finals. In addition, seeding of the teams according to their UEFA coefficients is used. The competition system has been undergoing changes since the 1991/92 season (see history). The current system was adopted in 2003.