The regular season uses a double round-robin format, in which each team plays the others home and away.

There is relegation and promotion between both the Rugby Pro D2 and Nationale 2, the fourth-level competition.

Nationale conducts a play-off system similar to the one currently used in Pro D2, with the top six teams qualifying for the play-offs and the top two teams receiving byes into the semi-finals.

The winner of the play-offs earns the league championship and automatic promotion to the next season's Prod D2; the runner-up enters a play-off with the second-from-bottom Pro D2 team, with the winner of that play-off taking up the final place in Pro D2.

The semi-finals and final take place in May, with the semi-finals being held over two-legs and the final taking place at a predetermined site.