In Brawl, each match had one, or more, "game series" that it covered, and the opponent and stage was chosen based on that. The modifiers were random. For example, the first stage was always Zelda themed, which meant fighting in the Twilight Princess or Wind Waker stages, against Link, Toon Link, Zelda or Ganondorf. The conditions were random too, so, aside from a 1 vs 1 battle, you could get matches like player and Link vs Ganondorf and Zelda. The second stage could be either Yoshi or Donkey Kong themed, following the same pattern (in the case of team matches, characters from the available series in that spot fill the team), although the stage matches each series there (so, if you got a simple player vs Yoshi, you'd only fight in the Yoshi stage).