In the Lylat system, a binary star's planets harbor evolved animal civilizations locked in an ancient struggle between order and chaos. When the exiled scientist Andross transforms Planet Venom into a staging ground for an invasion of the peaceful world Corneria, General Pepper faces an existential threat to his entire civilization. Lacking time to field trained pilots for the experimental Arwing fighter, he recruits Fox McCloud and his elite mercenary squadron—Falco, Peppy, and Slippy—to intercept Andross's assault across the system's varied worlds and outposts. The player's tactical choices during this campaign determine which theaters of war become accessible, shaping a unique path through the unfolding conflict.