Tallaso, a world located within the Tallaso system, could be found in the D'Aelgoth sector of the Western Reaches, which itself was part of the Mid Rim. This planet is classified as a planet. During the reign of the Galactic Empire, the Human named Riggins Delahrg held the position of Imperial governor on Tallaso. This individual, Riggins Delahrg, exploited his position by demanding money from the indigenous planetary government of Tallaso and accepting bribes from both galactic business organizations and criminal groups seeking to take advantage of the planet's assets. Delahrg's role guaranteed a luxurious existence for him and provided considerable local influence, although his power was comparatively minor within the broader framework of the Galactic Empire.
Following the Battle of Endor in 4 ABY, as the Empire began to disintegrate, Tallaso was abandoned by Imperial forces. As a result, the people of the planet revolted, removing Delahrg from his position. Delahrg resorted to theft before escaping, eventually making his way to the Vandron system, which housed the nearest operational Imperial bureaucracy.
The planet Tallaso was first referenced in Heroes & Rogues, a sourcebook from 1995. This book was written by Rick Stuart and Paul Sudlow for use with Star Wars: The Roleplaying Game by West End Games. In 2009, the reference work The Essential Atlas specified the location of the Tallaso system, and consequently the planet, as grid square K-17.