No playoffs in football except Australia. Generally, if you're 1st in the league, you win.
To further explain it and confuse it, the way the leagues in England(and the rest of Europe) work is like this:
In England, there are 20 teams in the Premier League. At the end of the season, the top four teams qualify for the Champion's League. The 5th place team gets into the Europa League, which is a pointless tournament.
The bottom three teams get relegated to the League Championship, the division below the PL. The top two teams from the Championship get promoted, along with the winner of the 4-team playoff between teams 3-6. The Championship and leagues below have similar promotion/relegation, so a team can have a monumental collapse and fall several tiers in a few years. I think Leeds did that. In Italy, they had a match-fixing scandal that saw one team dropped two levels as punishment. edit: I might be wrong about that. AC Milan was threatened with that punishment, but they managed to get out of it.
They also have two domestic tournaments through the season, the FA Cup(762 teams were in it this season) and the League Cup(92 teams).
MLS, even though you didn't ask, tries to be a hybrid of the European league system and the American playoff system, much like Australia. Last year's(and many years before) setup was with split league with East/West conferences, even though every team played every other team twice. Then they had the top 3 teams in each side go into the playoffs with wildcard spots between the 4 top ranked teams that didn't qualify. Dumb system, as that allowed a West team to win the Eastern Championship. They've changed it a lot for this year, with each team playing 3 games against conference opponents and 1 against non-conference opponents. Not sure if they've addressed the wildcard idiocy or not.