The story
Access Match Era (2017-present)
Starting in the 2017-18 Pro D2 season LNR introduced a new playoff format which the top six teams in the table would qualify for. Teams finishing first and second in the table would receive a bye while the third through sixth teams contest the first playoff round, with the winners advancing to play away in the semi-final. The Pro D2 final is then held at the home ground of the highest remaining seed, the winner of this game is crowned Pro D2 champions and gains direct promotion to the Top 14, replacing the team who finished bottom in the table.
The runner up contests an access match at their home ground against the team who finished second bottom in the Top 14, for the right to play in the Top 14 the next season.
Starting in the 2023–24 season the second bottom side in the Pro D2 contests a similar access match with the runner up of the Nationale, with both teams playing for the right to play in the Pro D2 the next year.
1st Place Promotion and Playoff Expansion to 5th Placed Sides (2004-2017)
Following the reduction of the Top 16 to the Top 14 the promotion format for the Pro D2 was changed to increase competition in the playoffs, as previously there was no jeopardy for the team having already won the league. Starting in the 2005–06 season the team finishing at the top of the table in the regular season was declared the winner and received automatic promotion to the Top 14. Teams placed 2nd through 5th then played in a direct playoff format to fight for the 2nd promotion slot.
During the 2004–05 season a playoff occurred in the Pro D2, however instead of automatic promotion, as would follow, the playoff winner became host for an Access Match for the 13th finishing side in the then Top 16. This match was won comprehensively by Section Paloise, meaning Stade Aurillacois were not promoted.
Notes
§ In this season the Top 16 relegated additional teams to become the Top 14, therefore the first access match was played between Stade Aurillacois, winners of the Pro D2 playoffs, and Section Paloise, the 13th placed team in that years Top 16. The access match finished 13-46 and so despite winning the playoff format, Stade Aurillacois were not promoted.
Establishment of the Pro D2 (2001-2004)
For the first season of the Pro D2 it was decided that promotion would be given to the top two sides in the table, however following that first year a playoff format was introduced, with the top 4 sides qualifying and playing in a single elimination bracket to decide the champion for that season, and subsequent promotion to the Top 14. The second promotion slot was given to the remaining playoff team which had the highest position in the league table.
From Wikipedia’s article on Pro D2, shared under CC BY-SA 4.0.4