John McGlashan College won this year's competition after beating South Otago High School in the straight final between the top two teams.
The Otago secondary schools rugby council met on Friday night to decide on the future of the competition, and opted for the inclusion of semifinals.
It is the only significant change to the 10-team competition, which will kick off on April 30 and include the same 10 schools as this year.
All schools will meet over the first nine weeks before the top six split into two pools of three: the first, third and fifth-ranked teams in one and the second, fourth and sixth in the other.
They will carry all points from their first nine games into the next phase before playing three cross-pool games, with the top four advancing to the semifinals.
The bottom four teams after the first nine weeks will combine with the top two teams from the under-18 division one grade, which was West Otago and the Otago Boys' Third XV this year.
To accommodate the introduction of semifinals, the competition is starting a week earlier and will wrap up on August 6.
This year's competition lacked interest after the top six was formed, as John McGlashan and South Otago had already all but booked their spots in the automatic final.
Otago secondary schools rugby council chairman Murray Munro said naming sponsor Southern Wide Real Estate had been retained, and the Otago Daily Times is also again on board.
''We had a good review of the season and everyone was delighted with the way it went,'' Munro said.
''We're delighted to have next year's format sorted in September. It took until March last time with all the changes.''
With sponsors on board, teams would again be spared the $3500 fee teams were hit with under the old Highlanders competition, and travel would again be subsidised, Munro said.
While there had been talk in recent months of a few Southland schools wanting to reignite a joint Otago-Southland competition, no Southland schools had officially approached the Otago secondary schools council.
A two-week window had been left after the conclusion of the competition to decide which Otago or Southland team would compete in the South Island final.
