The revised structure, which has been approved by the RFU Board, will now see the bottom side following the 22 regular-season Championship matches relegated to SSE National League One while the top four will go on to compete in two-legged semi-finals, which will be followed by a two-legged final.
The system for the recently-completed 2010/11 season saw the top eight sides after the 22 matches go into the promotion play-offs and the remaining four teams in the relegation play-offs. The new structure will also provide a minimum of six games in the revised British & Irish Cup.
Rob Andrew, the RFU's professional rugby director, said: "The reduction from an eight team promotion play-off to four will ultimately reward those clubs who best perform across the season, whilst encouraging a hugely competitive league to reach the top four.
"The amended structure also shows a further commitment to the British & Irish Cup which will include six pool matches played on a similar format to ERC competitions."
Geoff Irvine, chairman of the Championship Clubs, said: "The clubs believe these changes will improve the competition, providing quality rather than quantity of fixtures. It should also help with congestion of fixtures which results in player welfare issues."