Ajax
Anderlecht
Arsenal
Barcelona
BATE
Bayern
Benfica
Braga
Celtic
CFR Cluj
Chelsea
Dinamo Zagreb
Dortmund
Dynamo Kyiv
Galatasaray
Juventus
LOSC
Málaga
Man. City
Man. United
Milan
Montpellier
Nordsjælland
Olympiacos
Porto
PSG
Real Madrid
Schalke
Shakhtar Donetsk
Spartak Moskva
Valencia
Zenit
AEL
Anderlecht
Basel
BATE
Celtic
CFR Cluj
Club Brugge
Debrecen
Dinamo Zagreb
Dudelange
Dynamo Kyiv
Ekranas
Fenerbahçe
Feyenoord
H. Kiryat Shmona
Helsingborg
HJK
København
Liberec
Maribor
Molde
Motherwell
Neftçi
Panathinaikos
Partizan
Sheriff
Śląsk
Vaslui
AEL
Basel
BATE
Budućnost Podgorica
Debrecen
Dinamo Zagreb
Dudelange
Ekranas
Flora
H. Kiryat Shmona
Helsingborg
HJK
KR
Liberec
Linfield
Ludogorets
Maribor
Molde
Neftçi
Partizan
Salzburg
Shakhter
Shamrock Rovers
Sheriff
Skënderbeu
Śląsk
TNS
Ulisses
Valletta
Vardar
Ventspils
Željezničar
Zestafoni
ŽilinaThe UEFA Champions League comprises three qualifying rounds, a play-off round, a group stage and four knockout rounds.
Qualifying
In matches in the three qualifying rounds and the play-off stage, clubs play two matches against each other on a home-and-away basis. The club which scores the greater aggregate of goals qualifies for the next round, with away goals and then penalties used to determine the winner in the event of a draw.
Group stage
The ten winners in the play-off round ties – five from the best-placed path and five from the champions path – join 22 automatic entrants in the 32-team group stage. The clubs are split into eight groups of four teams, who play home and away against each of their pool opponents between September and December to decide which two teams from each section advance to the first knockout round. The third-place finishers in each group enter the UEFA Europa League round of 32.
Knockout phase
From the last 16 until the semi-finals, clubs play two matches against each other on a home-and-away basis with the same rules as the qualifying and play-off rounds applied. In the last 16, group winners play runners-up other than teams from their own pool or nation, while from the quarter-finals on the draw is free.
Final
The final is decided by a single match, which this season will be played at Wembley Stadium on Saturday 25 May 2013.
Further details, including the criteria for separating teams that finish level on points in a group, can be found in the official competition regulations.