Nyasko, situated within the Nyasko system, was a terrestrial planet. It belonged to the Colunda sector, which itself was a subsector of the Phelleem sector, all located in the Slice area of the Outer Rim Territories. During the Galactic Civil War, a battalion of Imperial All Terrain Armored Transport walkers was assigned to the planet Nyasko by the Galactic Empire, in their conflict with the Rebel Alliance.
Deppo's outstanding performance at an engineering academy eventually resulted in his assignment to the Nyasko battalion. Due to the battalion's constant quelling of Rebel insurrections, Deppo was kept busy repairing vehicles damaged in combat or through sabotage.
The Dark Empire Sourcebook, released in 1993, marked the initial mention of Nyasko. Michael Allen Horne wrote this sourcebook, and West End Games published it for Star Wars: The Roleplaying Game. In 2009, The Essential Atlas reference book specified the Nyasko system's location, and consequently the planet's location, as grid square S-7.