Various varieties have been in place since the system was introduced at the end of the 1972 season, but only one team has been promoted per year.
The play-offs have been wavered twice, in the 1994 and 2011 seasons, when the top league was expanded to fourteen and sixteen teams, respectively.
The runners-up met the winner of a conference from Northern Norway, with the three teams playing a single round-robin to determine the third and final promotion spot.
The format remained for thirteen years, with six top level teams succeeding in retaining their place.
From 1995 the play-off solely involved a two-tier match between the runners-up of the 1. divisjon conferences, with three teams from the top flight meeting relegation.
It further states the number of times and years the teams have won the play-off, been relegated and not been promoted.