The tournament will be played in accordance with World Rugby's Laws of the Game of Rugby Union (as amended from time to time), as varied or supplemented by EPCR.
2.1 For the pool stage, the clubs are divided into five pools of four.
2.2 Four points for a win, two points for a draw. A bonus point will be awarded to a club scoring four or more tries and to a club losing by seven points or fewer.
2.3 The five pool winners and three best-placed runners-up will qualify for the quarter-finals and will be decided as follows:
(a) The pool winner will be the club with the highest number of match points in each pool. The best-placed runners-up will be the three clubs with the highest number of match points out of the five clubs that finish second in their respective pools. For the quarter-finals, the pool winners will be ranked 1 to 5 and the best-placed runners-up 6 and 8 by reference to the number of match points earned.
(b) If two clubs in the same pool are equal on match points at the end of the pool stage, their ranking will be determined by the results of the two matches played between the relevant clubs as follows:
(i) the club with the greater number of match points from those matches; or
(ii) if equal, the club with the best aggregate points difference from those matches: or
(iii) if equal, the club that scored the most tries in those matches.
(c) If ranking remains unresolved and/or if clubs have not played each other previously in the pool stage, qualification/ranking will be determined as follows:
(i) the best aggregate points difference from the pool stage; or
(ii) if equal, the number of tries scored in the pool stage; or
(iii) if equal, the club with the fewest number of players suspended under Disciplinary Rules in the pool stage; or
(iv) if unresolved, by drawing lots.
2.4 The clubs ranked 1 to 4 will have home advantage for the quarter-finals as follows:
Club 1 v Club 8 (QF1)
Club 4 v Club 5 (QF2)
Club 3 v Club 6 (QF3)
Club 2 v Club 7 (QF4)
NB The format for the semi-final matches in the Challenge Cup recognises performances by clubs during the pool stages as well as the achievement of a winning a quarter-final match away from home.
The winner of QF1 will play the winner of QF2 in one semi-final, and the winner of QF3 will play the winner of QF4 in the other semi-final as follows:
Semi-final 1: winner QF1 v winner QF2
Semi-final 2: winner QF3 v winner QF4
The semi-final matches will be played at home venues, and the following clubs will have home venue advantage in their respective semi-final matches:
(a) For Semi-final 1
If the clubs ranked 1 and 4 win their QFs, the club ranked 1 will have home venue advantage
If the clubs ranked 1 and 5 win their QFs, the club ranked 5 will have home home venue advantage
If the clubs ranked 8 and 4 win their QFs, the club ranked 8 will have home venue advantage
If the clubs ranked 8 and 5 win their QFs, the club ranked 5 will have home venue advantage
(b) For Semi-final 2
If the clubs ranked 3 and 2 win their QFs, the club ranked 2 will have home venue advantage
If the clubs ranked 3 and 7 win their QFs, the club ranked 7 will have home venue advantage
If the clubs ranked 6 and 2 win their QFs, the club ranked 6 will have home venue advantage
If the clubs ranked 6 and 7 win their QFs, the club ranked 6 will have home venue advantage
2.5 The final match will be played at a venue designated by EPCR.
2.6 In the event of a tie at full-time in the quarter-finals, semi-finals or final, extra time of 10 minutes each way will be played. If the scores remain tied, the winner will be determined as follows:
(a) the club that scored the most tries in the match (including extra time) or
(b) if equal, by a place-kick competition.
3.1 Each club must nominate a squad of up to 41 players. A minimum of 10 of the players nominated by the club must be capable of playing in front row forward positions. All such players must, on registration, be fully and properly registered with their club and Union and available to play for the club from that date.
3.2 A club must nominate a squad of between 19 and 23 players for each match.
3.3 A minimum of six front row players must be included in each match squad such that on the first occasion that a replacement is required in each position, a replacement can be made. Where uncontested scrums are ordered due to the departure of a front row player and there is no suitable replacement, the player whose departure caused the uncontested scrums may not be replaced (ie. the club will be required to play with 14 players).
3.4 In order to reduce the possibility of uncontested scrums, each club may also nominate further front row players, referred to as Emergency Front Row players, who may be registered with EPCR on a match-by-match basis provided that all necessary details of the players have been submitted before 12 noon (GMT) on 22 September 2016. The provision for the nomination of Emergency Front Row players is not intended to allow clubs to improve the quality of their squads, and is designed to cater for illness and/or injury in the relevant positions. The players added to squads will typically come from a club's academy or similar.
3.5 Each club may register up to three additional players during the pool stage, each to replace a player previously registered. If a club registers three additional players, one such player must be a front row player. Additional players must have a three-month contract with the club and must not have played for another club in the tournament. Additional player registrations must be submitted by 12 noon (GMT) on the Tuesday before the match. De-registered players may be re-registered (in place of the relevant additional players) during the pool stages.
3.6 Each club involved in the knockout stage may register up to three further players. If a club registers three further players, one such player must be a front row player. Such registrations must be submitted by 12 noon (GMT) on 16 March 2017. The players in question must not have played for another club in the tournament.
3.7 Each club is permitted a maximum of two 'non-European players' in each match squad.
4.1 For pool matches and quarter-finals, if a club fails to wear the strip designated by EPCR and there is a colour clash, that club must change strip. For the semi-finals and final, in the event of a colour clash, the club to change strip will be at EPCR's discretion.
5.1 Players will be subject to doping control as set out in EPCR's Anti-Doping Programme, which is based on and subject to Regulation 21 (Anti-Doping) of World Rugby's Regulations.
6.1 Where reasonably practicable, a player shown a red card will have his case heard within seven days of the relevant match.
6.2 EPCR will appoint a Citing Commissioner for each match. The Citing Commissioner will be entitled to cite a player for any acts of Foul Play that warranted the player being shown a red card. Clubs will not have the power to cite a player but may refer incidents to the Citing Commissioner within 26 hours of the start of the match. The Citing Commissioner will have 50 hours from the start of the match to submit a citing complaint to EPCR, although this deadline may be extended in certain circumstances. EPCR may refer the complaint to a Citing Officer (also referred to as a 'Gatekeeper') to determine whether it should proceed. The case will then proceed to a disciplinary hearing.
7.1 Where a match is abandoned after 60 minutes or more, the result will stand.
7.2 Where a match is abandoned after fewer than 60 minutes, (a) if both clubs and the EPCR Board agree, the result will stand, or (b) the match will be replayed in full no earlier than 48 hours after kick-off of the abandoned match (unless both clubs and EPCR agree otherwise), with both clubs entitled to select new teams.
8.1 Each club must announce its match squad by 12 noon (GMT) on the Wednesday before a Thursday match, by 12 noon (GMT) on the Thursday before a Friday match and by 12 noon (GMT) on the Friday before a weekend match. The match squad announced must not differ from the squad that plays save in exceptional circumstances. Breaches of the match squad regulations may result in fines being imposed by the Board of EPCR.