MLS playoff format
Major League Soccer revised its playoff format for the 2012 season. Here is a rundown of how it works: The conference semifinals will be decided by two-game aggregate series, with the lower-seeded team hosting the first leg. If the total score is tied after 180 minutes of action, two 15-minute extra time periods will be played in their entirety. If the total score still is tied, the winner will be decided by penalty kicks. The conference championships will follow the same format as the semifinals. MLS Cup will be a single match hosted by the higher-seeded team. If the score is tied after 90 minutes of play, two 15-minute extra time periods will be played in their entirety. If the score still is tied, the match will be decided by penalty kicks.
-- Source: Major League Soccer