|2017–18 European Rugby Champions Cup|
|Tournament format(s)||Round-robin and knockout|
|Date||13 October 2017 – 12 May 2018|
|Attendance||1,005,537 (15,008 per match)|
52,282 – Leinster v Racing 92|
(12 May 2018)
2,600 – Benetton v Scarlets|
(16 December 2017)
|Tries scored||366 (5.46 per match)|
|Top point scorer(s)||
Owen Farrell (Saracens)|
|Top try scorer(s)||
Dan Evans (Ospreys)|
|Venue||San Mamés Stadium, Bilbao|
|Champions||Leinster (4th title)|
The 2017–18 European Rugby Champions Cup was the fourth European Rugby Champions Cup championship, the annual rugby union club competition for teams from the top six nations in European rugby and was the twenty-third season of pan-European professional club rugby competition.
The format of the competition began with a play-off qualification round at the end of the preceding season featuring teams from England, France, Ireland and Wales. The winner joined 19 teams already qualified by way of their domestic league position in the pool stage of the competition - a home and away round-robin for five groups of four teams. Following the pool stage, five pool winners, and three highest ranked runners-up, qualified for the quarter-finals of the competition, as the Cup thereafter reverted to a single elimination knockout format.
The tournament began on 13 October 2017. The final was won by Leinster on 12 May 2018 at San Mamés Stadium in Bilbao, Spain. This was Leinster's fourth title, tieing the record for the most successful team in the competition's history.  This was the first time the final was held outside one of the Six Nations countries.
Twenty clubs from the three major European domestic and regional leagues competed in the Champions Cup. Nineteen of these qualified directly as a result of their league performance.
The distribution of teams was:
The following teams qualified for the 2017–18 tournament.
|Aviva Premiership||Top 14||Pro12|
Four clubs competed in a play-off to decide the final team in the Champions Cup.
The two Pro12 teams played either the Premiership or Top 14 side in a single-leg semi-final, held at the home ground of the non-Pro12 side. The winners of these matches then played in a play-off final, and the winner of this match took the 20th place in the Champions Cup. The three losing teams will all compete in the 2017–18 European Rugby Challenge Cup.
The following teams took part:
|Aviva Premiership||Top 14||Pro12|
|Northampton Saints||Stade Français||Connacht||Cardiff Blues|
A draw was held on 15 March 2017 to determine the two semi-final matches, and the semi-final winner that would have home advantage in the final.
19 May 2017
|Stade Français||46 – 21||Cardiff Blues|
20 May 2017
|Northampton Saints||21 – 15||Connacht|
26 May 2017
|Northampton Saints||23 – 22||Stade Français|
Below is the list of coaches, captain and stadiums with their method of qualification for each team.
Note: Placing shown in brackets, denotes standing at the end of the regular season for their respective leagues, with their end of season positioning shown through CH for Champions, RU for Runner-up, SF for losing Semi-finalist and QF for losing Quarter-finalist.
Director of Rugby
|Captain||Stadium||Capacity||Method of Qualification|
|Bath||Todd Blackadder||Matt Garvey||Recreation Ground||14,500||Aviva Premiership top 6 (5th)|
|Benetton||Kieran Crowley||Dean Budd||Stadio Comunale di Monigo||6,700||Pro12 top Italian team (10th)|
|Castres||Christophe Urios||Mathieu Babillot||Stade Pierre-Fabre[a]||12,500||Top 14 top 6 (5th) (QF)|
|Clermont||Franck Azéma||Damien Chouly||Stade Marcel-Michelin||19,022||Top 14 top 6 (2nd) (CH)|
|Exeter Chiefs||Rob Baxter||Jack Yeandle||Sandy Park||12,800||Aviva Premiership top 6 (2nd) (CH)|
|Glasgow Warriors||Dave Rennie||Ryan Wilson||Scotstoun Stadium||7,351||Pro12 top Scottish team (6th)|
|Harlequins||John Kingston||James Horwill||Twickenham Stoop||14,800||Aviva Premiership top 6 (6th)|
|La Rochelle|| Patrice Collazo
|Jason Eaton||Stade Marcel-Deflandre||16,000||Top 14 top 6 (1st) (SF)|
|Leicester Tigers||Matt O'Connor||Tom Youngs||Welford Road||25,800||Aviva Premiership top 6 (4th) (SF)|
|Leinster||Leo Cullen||Isa Nacewa||RDS Arena
|Pro12 top 7 (2nd) (SF)|
|Montpellier||Vern Cotter||Louis Picamoles||Altrad Stadium||15,697||Top 14 top 6 (3rd) (QF)|
|Munster|| Johann van Graan
(For Rassie Erasmus)[b]
|Peter O'Mahony||Thomond Park||26,200||Pro12 top Irish team (1st) (RU)|
|Northampton Saints|| Alan Dickens (For
Jim Mallinder) [c]
|Dylan Hartley||Franklin's Gardens||15,500||Play-off winner|
|Ospreys||Steve Tandy||Alun Wyn Jones||Liberty Stadium||20,827||Pro12 top 7 (4th) (SF)|
|Racing 92|| Laurent Labit
|Dimitri Szarzewski||Stade Yves-du-Manoir
U Arena [d]
|Top 14 top 6 (6th) (SF)|
|Saracens||Mark McCall||Brad Barritt||Allianz Park||10,000||Aviva Premiership top 6 (3rd) (SF)|
|Scarlets||Wayne Pivac||Ken Owens||Parc y Scarlets||14,870||Pro12 top Welsh team (3rd) (CH)|
|Toulon||Fabien Galthié||Duane Vermeulen||Stade Mayol||18,200||Top 14 top 6 (4th) (RU)|
|Ulster||Les Kiss||Rory Best||Kingspan Stadium||18,196||Pro12 top 7 (5th)|
|Wasps||Dai Young||Joe Launchbury||Ricoh Arena||32,609||Aviva Premiership top 6 (1st) (RU)|
The twenty competing teams are seeded and split into four tiers, each containing five teams.
For the purpose of creating the tiers, clubs are ranked based on their domestic league performances and on their qualification for the knockout phases of their championships, so a losing quarter-finalist in the Top 14 would be seeded below a losing semi-finalist, even if they finished above them in the regular season.
|4||Racing 92||Leicester Tigers||Ospreys|
Based on these seedings, teams are placed into one of the four tiers, with the top seed clubs being put in Tier 1. The nature of the tier system means that a draw is needed to allocate two of the three second seed clubs to Tier 1 and to allocate one of the three fourth seed clubs to Tier 2. The tiers are shown below. Brackets show each team's seeding and their league (for example, 1 Top 14 indicates the team was seeded 1st from the Top 14).
|Tier 1||Exeter Chiefs (1 AP)||Scarlets (1 Pro12)||Clermont (1 Top 14)||Wasps (2 AP)||Munster (2 Pro12)|
|Tier 2||Toulon (2 Top 14)||Saracens (3 AP)||Leinster (3 Pro12)||La Rochelle (3 Top 14)||Racing 92 (4 Top 14)|
|Tier 3||Leicester Tigers (4 AP)||Ospreys (4 Pro12)||Bath (5 AP)||Ulster (5 Pro12)||Montpellier (5 Top 14)|
|Tier 4||Harlequins (6 AP)||Glasgow Warriors (6 Pro12)||Castres (6 Top 14)||Benetton (7 Pro12)||Northampton Saints (Play-off)|
The following restrictions will apply to the draw:
Teams in the same pool play each other twice, at home and away, in the group stage that begins on the weekend of 13/14/15 October 2017, and continues through to 19/20/21 January 2018. The five pool winners and three best runners-up progress to the quarter finals.
Teams are awarded group points based on match performances. Four points are awarded for a win, two points for a draw, one attacking bonus point for scoring four or more tries in a match and one defensive bonus point for losing a match by seven points or fewer.
In the event of a tie between two or more teams, the following tie-breakers will be used, as directed by EPCR:
|Winner of each pool, advance to quarter-finals.|
|Three highest-scoring second-place teams advance to quarter-finals.|
|La Rochelle (5)||6||4||0||2||156||121||+35||18||17||3||1||20|
|Racing 92 (7)||6||4||0||2||128||105||+23||14||10||1||2||19|
The eight qualifiers were ranked according to their performance in the pool stage and competed in the quarter-finals which were held on the weekend of 30/31 March, 1 April 2018. The four top teams were at home in the quarter-finals against the four lower teams in a 1v8, 2v7, 3v6 and 4v5 format.
The semi-finals were played on the weekend of 20/21/22 April 2018. In lieu of the draw that used to determine the semi-final pairing, EPCR announced that a fixed semi-final bracket would be set in advance, and that the home team would be designated based on "performances by clubs during the pool stages as well as the achievement of a winning a quarter-final match away from home". Semi-final matches must be played at a neutral ground in the designated home team's country.
Home country advantage was awarded as follows:
30 March 2018
|Scarlets (4)||29–17||(5) La Rochelle|
|Try: Patchell 60' c
S. Williams 75' c
Con: Halfpenny (2/2) 62', 76'
Pen: Halfpenny (5/6) 4', 11', 18', 25', 45'
|Report||Try: Sazy 8' c|
Boudehent 80' c
Con: Balès (1/1) 9'
Noble (1/1) 80'
Pen: Balès (1/1) 40'
31 March 2018
|Munster (3)||20–19||(6) Toulon|
|Try: Murray 27' c
Conway 74' c
Con: Keatley (2/2) 28', 75'
Pen: Keatley (2/2) 31', 55'
|Report||Try: Ashton 64' c|
Con: Trinh-Duc (1/1) 65'
Pen: Belleau (1/1) 9'
Trinh-Duc (2/2) 60', 67'
Drop: Belleau (1/1) 18'
1 April 2018
|Clermont (2)||17–28||(7) Racing 92|
|Try: Betham 33' m
Pen: Parra (4/4) 5', 9', 17', 44'
|Report||Try: Nakarawa 24' c|
Andreu 63' c
Palu 65' m
Con: Machenaud (2/3) 24', 63'
Pen: Machenaud (3/4) 31', 40', 41'
1 April 2018
|Leinster (1)||30–19||(8) Saracens|
|Try: Ringrose 3' c
Leavy 46' c
Lowe 57' c
Con: Sexton (2/2) 3', 47'
McFadden (1/1) 58'
Pen: Sexton (3/3) 20', 33', 42'
|Report||Try: Cowan 63' c|
Con: Farrell (1/1) 64'
Pen: Farrell (3/3) 11', 15', 26'
Bosch (1/1) 34'
21 April 2018
|Leinster (1)||38–16||(4) Scarlets|
|Try: J. Ryan 9' c
Healy 26' c
McFadden 39' c
Fardy 49' c
Sexton 59' c
Con: Sexton (5/5) 10', 27', 40', 51', 60'
Pen: Sexton (1/1) 18'
|Report||Try: Beirne 78' c|
Con: Patchell (1/1) 79'
Pen: Halfpenny (3/3) 5', 21', 33'
22 April 2018
|Racing 92 (7)||27–22||(3) Munster|
12 May 2018
|Pen: Sexton (3/5) 16', 38', 53'
Nacewa (2/2) 73', 78'
|Report||Pen: Iribaren (4/5) 3', 21', 44', 70'|