The 'Super Eight' structure of the Super League will be scrapped at the end of the season.
The format involved the top two flights being split into three tiers of eight, leaving the middle eight to play in the Qualifiers for the final four positions in the following campaign of the Super League.
A one-up, one-down relegation system will be introduced from 2019, following masses of criticism of the original scheme.
"We have looked at a competitive structure that really isn't working: effectively it provides too much uncertainty," new Super League chief executive Robert Elstone told reporters.
"The job starts with building a positive working relationship with the Rugby Football League and that's recognising Super League's responsibilities to the wider game, too."
The Leeds Rhinos were the only club to vote against the changes to the rules.