Route 20 starts from the south at Floccesy Town, where a Youngster and a Lass are. The northern section of the route leads to Floccesy Ranch before looping southwest to the route's western exit. Although this route appears early in the game, travelers cannot head eastwards until they have earned their first badge.
Once the Basic Badge has been obtained, Hiker Jerome will let them pass. The route continues down a set of steps into a small valley, before heading east to Virbank City. This route is the first place travelers from Aspertia City will encounter dark grass.
During the autumn season, leaves will pile up at various spots on the route. This enables access to secluded items not reachable in other seasons, as well as trainers on the south end of the route. Also, Route 20, Floccesy Town and Floccesy Ranch may occasionally rain in unison.
Route 20 first appeared in Legendary Tornadus. Blake and Whitley traveled there to find out what happened to a delivery truck carrying supplies for an upcoming school event. In reality, Blake and Looker were investigating the area to find and arrest Giallo, one of the Seven Sages who had been spotted in the area. Shortly after arriving, Blake and Whitley were attacked by Tornadus, which proceeded to transform into its Therian Forme.
Outmatched by the Cyclone Pokémon's power, Blake is forced to send out his newest team member, Kelden, and has it battle alongside Dewott in order to take down Tornadus. As they battle, Blake discovers that Tornadus was actually going after Giallo, who had rejected Colress as the new leader of Team Plasma. With Tornadus too focused on trying to capture Giallo, it easily falls to Dewott and Kelden's combination, forcing the Team Plasma Grunts controlling to recall it and retreat. After Giallo is arrested, the supplies are successfully delivered to the Trainers' School.