The PRO16 (known as the Guinness PRO16 for sponsorship reasons) is an annual rugby union competition involving professional sides from Canada, Ireland, Italy, Scotland, South Africa, the United States, and Wales. The league is one of the three major professional leagues in Europe (along with the English Premiership and the French Top 14), the most successful European teams from which go forward to compete in the European Rugby Champions Cup, the pan-European championship which replaced the Heineken Cup after the 2013–14 season. The Pro14 is the second domestic club competition in the professional era to span both the Northern and Southern Hemispheres, and the second, to the Southern Hemisphere competition Super Rugby, to cross continents and to span both the Western and Eastern Hemispheres.
Tournament format
editThe league season takes place between September and May, with teams split into four conferences; each consisting of one Irish and Welsh team and two teams from two of Italy, Scotland, South Africa, and North America (either Canada or the United States) to make a four team conference. The winners and runners-up of each conference advance to the play-offs.
Regular season
editEach year the teams will be seeded 1 to 16 based on their previous year's final positioning: first by play-off result, then by regular season record. The seedings for the current season are as follows:
| Seed | Team | Method used for seeding |
|---|---|---|
| 1 |  Leinster |
2017–18 Pro14 champions |
| 2 |  Scarlets |
2017–18 Pro14 runners-up |
| 3 |  Glasgow Warriors |
2017–18 Pro14 losing semi-finalists (76 points) |
| 4 | Munster |
2017–18 Pro14 losing semi-finalists (69 points) |
| 5 | Edinburgh |
2017–18 Pro14 losing quarter-finalists (68 points) |
| 6 |  Cheetahs |
2017–18 Pro14 losing quarter-finalists (63 points) |
| 7 | Ulster |
62 points |
| 8 |  Benetton |
55 points |
| 9 | Cardiff Blues |
54 points |
| 10 | Ospreys |
44 points |
| 11 | Connacht |
39 points |
| 12 | Zebre |
36 points |
| 13 | Dragons |
20 points |
| 14 | Southern Kings |
11 points |
| 15 |  Toronto Nomads |
New club (won draw) |
| 16 |  New York Knights |
New club (lost draw) |
The positions in each conference are also seeded 1 to 16:
| Conference A | Conference B | Conference C | Conference D |
|---|---|---|---|
| 1 | 2 | 3 | 4 |
| 8 | 7 | 6 | 5 |
| 9 | 10 | 11 | 12 |
| 16 | 15 | 14 | 13 |
The teams are then placed in conferences starting with the highest seeded (#1) team and continuing in order through the lowest seed (#16) team. Each team is placed in the highest seeded position available such that:
- No conference has more than one team from the same country, or more than one team from North America.
- Each conference has exactly one team from Ireland and exactly one from Wales.
The conferences for this season are as follows:
| Conference A | Conference B | Conference C | Conference D |
|---|---|---|---|
| Leinster |
Scarlets |
Glasgow Warriors |
Munster
|
| Benetton |
Ulster |
Cheetahs |
Edinburgh
|
| Cardiff Blues |
Zebre |
Ospreys |
Dragons
|
| New York Knights |
Toronto Nomads |
Connacht |
Southern Kings
|
The regular season is made up of 21 rounds:
- 1 home and 1 away game against each team in their own conference (6 games total).
- 1 game, either home or away, against the teams in the other conferences (12 games total).
- 3 additional regional derbies.
- Each Irish team will play the Irish teams in the other conferences an additional time, such that each derby is played once at home and once away.
- Each Welsh team will play the Welsh teams in the other conferences an additional time, such that each derby is played once at home and once away.
- Each Italian team will play the other Italian team three additional times, such that the derby is played twice at home and twice away.
- Each Scottish team will play the other Scottish team three additional times, such that the derby is played twice at home and twice away.
- Each South African team will play the other South African team three additional times, such that the derby is played twice at home and twice away.
- Each North American team will play the other North American team three additional times, such that the derby is played twice at home and twice away.
Play-offs
editEight teams will qualify for the championship play-offs: the winners and runners-up of each conference. The conference winners will be seeded 1 to 4 based on their regular season records, while the runners-up will be seeded 5 to 8. The conference winners compete in two play-offs in the first round, with the winners receiving byes to the semi-finals as hosts and the losers advancing to the quarter-finals as hosts. The conference runners-up compete in two elimination play-offs in the first round, with the winners advancing to the quarter-finals as the away teams. The quarter-final winners advance to the semi-finals as the away teams and challengers to the two teams that received byes. The winners of the semi-finals advance to the final, played on a neutral site. This season, the final will be played at Aviva Stadium in Dublin.
| First round | Quarter-finals | Semi-finals | Final | ||||||||||||||||
| Match 1 | |||||||||||||||||||
| 1 | Conference winner #1 | Home | |||||||||||||||||
| 4 | Conference winner #4 | Away | Quarter-final #1 (QF1) | ||||||||||||||||
| Losers of match 1 | Home | ||||||||||||||||||
| Match 2 | Winners of match 2 | Away | Semi-final #1 (SF1) | ||||||||||||||||
| 5 | Conference runner-up #1 | Home | Winners of match 1 | Home | |||||||||||||||
| 8 | Conference runner-up #4 | Away | Winners of QF2 | Away | Final – Aviva Stadium, Dublin | ||||||||||||||
| Winners of SF1 | |||||||||||||||||||
| Match 3 | Semi-final #2 (SF2) | Winners of SF2 | |||||||||||||||||
| 6 | Conference runner-up #2 | Home | Winners of QF1 | Away | |||||||||||||||
| 7 | Conference runner-up #3 | Away | Quarter-final #2 (QF2) | Winners of match 4 | Home | ||||||||||||||
| Winners of match 3 | Away | ||||||||||||||||||
| Match 4 | Losers of match 4 | Home | |||||||||||||||||
| 2 | Conference winner #2 | Home | |||||||||||||||||
| 3 | Conference winner #3 | Away | |||||||||||||||||