The number of automatic qualifiers for the Rugby World Cup will increase from eight to 12 for the 2011 tournament being staged in New Zealand.
New Zealand beat Japan and South Africa for the right to host 2011
The top three teams in each of the four pools in this year's tournament will avoid having to play qualifiers.
International Rugby Board chairman Dr Syd Millar said one of the reasons was to cut down on fixture congestion.
"This will reduce the potential number of games that have to be played in the years before a tournament," he said.
He also said it would help raise the standard of the game in countries outside the Home Nations and Tri-Nations and make games in this year's tournament more meaningful.
"It raises the prospect of several Tier Two unions qualifying automatically," he added.
"It will add excitement and relevance to more pool matches at each tournament, including the 2007 World Cup."