* The annual competition features regional teams from the southern hemisphere, five each from New Zealand, South Africa and Australia.
* The British and Irish Lions tour of Australia in June/July has meant an early start for Australia's teams, who begin play on Friday. All teams will start the 'proper' first round on Feb. 22.
* The competition started as the Super 12 in 1996, a year after the sport turned professional, and was expanded to 14 teams from 2006 and 15 in 2011 after the Melbourne Rebels were added.
* The competition changed to a conference-based system for each country in 2011, extending the season and guaranteeing more local derbies.
* South Africa's Southern Kings, based in Port Elizabeth, will join the competition this year as the country's fifth representative, replacing the Johannesburg-based Lions, who finished last in the 2012 competition.
* The Lions will play a two-legged promotion/relegation playoff against the team that finishes bottom of the South African conference for entry to the 2014 competition.
* Each team will play the other four sides in their conference at home and away, and four of the sides in each of the other two conferences once to give a total of 16 games.
* Each team will also receive two bye weeks throughout the competition.
* Teams earn four points for a win, two for a draw, plus a bonus point for scoring four tries in a match or losing by less than seven points.
* The top side in each conference will advance to the playoffs in the positions 1, 2, 3 dependent on their individual competition points.
* The teams ranked four to six, based on their points total, will also qualify for the playoffs and can come from any conference.
* Teams ranked one and two will receive a bye in the first round of the playoffs with the third-ranked team playing the sixth ranked side, while the fourth ranked side will play the fifth. The higher ranked teams have home advantage.
* The winners of each of those first round of matches will then advance to the semi-finals against Team 1 and Team 2, with the lowest ranked qualifier playing the top seed on the weekend of July 1/2. Teams 1 & 2 have home advantage.
* The two winners advance to the final on Aug. 4.
* New Zealand teams have dominated the competition, winning 11 of the 17 finals. The Canterbury Crusaders are the most successful with seven titles.
* The Waikato Chiefs are defending the title having won it for the first time last year.
* South Africa's Bulls are the only South African champions, having won the title in 2007, 2009, 2010.
* Australia's ACT Brumbies have won the title twice, while the Queensland Reds won it in 2011. (Compiled by Greg Stutchbury; Editing by Nick Mulvenney)