From 18 to 15
Three teams to be cut - one from Australia and two from South Africa.
Competition goes from 18 teams and four conferences to 15 teams in three conferences.
New Zealand - Blues, Chiefs, Hurricanes, Crusaders, Highlanders
Australia - Four Australian teams plus Japan's Sunwolves
South Africa - Four South African teams plus Argentina's Jaguares.
120-match regular season plus eight-team, seven-match finals series
18 rounds (16 matches per team, two bye weeks)
Each team will play eight matches within their conference (four home and four away)
Each team will play eight cross-conference matches - against four of the five teams from each of the other two conferences (four at home and four away)
Each team will play 12 of the other teams within the season (85 per cent of opposition teams, is up from 70 per cent in 2016).
Finals series: Three conference winners and five wild card places - the next-best performing teams based on competition points after the conference winners regardless of conference. Conference winners and fourth-placed team on competition points will host quarter-finals.