Oon Tien existed as a planet situated within the Kathol sector of the expansive Outer Rim Territories. It also served as the original homeworld for the Jarell species. Around 300 years prior to the outbreak of the Galactic Civil War, this planet was discovered by Galactic Republic colonists, which then led to its inhabitation by Humans. The indigenous Jarell monarchies engaged in trade with the newly arrived Human settlers, obtaining advanced technology and weaponry that instigated a transformation within Jarell society. Leading up to the Galactic Civil War, Oon Tien underwent integration into the Kathol sector, evolving into a significant center for both agricultural production and manufacturing.
After Oon Tien was brought under the control of the Imperial regime, Moff Kentor Sarne, the governor overseeing the sector, proceeded to construct stardocks in orbit around the planet. This action transformed Oon Tien into the central location for the construction and upkeep of his fleet. Even after Moff Sarne proclaimed himself a warlord following the death of Emperor Palpatine during the Battle of Endor, Oon Tien remained under his dominion. In the year 8 ABY, Kal'Shebbol, Sarne's sector's capital, fell to the New Republic. As Sarne began his retreat, he gave the order for Governor Manon Flint to defend the stardocks against any New Republic advances, no matter the cost. As the New Republic worked to increase its influence in the area, the planet would cause problems for them.
Oon Tien was a planet that resided in the Oon Tien system, which itself was located in the Kathol sector of the Outer Rim Territories. Hyperspace travel routes connected Oon Tien to the Torize, Kolatill, and Corjain systems, placing it close to the Trition Trade Route. Oon Tien was Torize's neighbor at fourteen hours away, Kolatill was nineteen hours distant, and travel to Corjain took eleven hours. Oon Tien, a wet, water-covered, and mountainous world, functioned as the original homeworld for the Jarell species. As the world was brought into the Kathol sector's economic structure, it developed into a major hub for agricultural activities and manufacturing. After the Imperial forces took control, the planet became home to the largest shipyard in the sector, thanks to Moff Kentor Sarne, who ruled the Kathol sector as an Imperial official and later as a warlord. He had three stardocks built in orbit. Sarne defended the Oon Tien system with at least two dozen IPV-1 System Patrol Craft, a full wing of TIE Fighters, and hundreds of proton mines because the planet served as a major maintenance hub for his fleet.
The Jarells, native to the planet, had a basic society based on monarchic city-states and had developed basic metalworking skills when Galactic Republic colony ships found the system around 292 BBY. Human colonists made their homes on the planet, constructing multiple settlements and coexisting with the Jarell city-states. The Jarell monarchs began trading valuable gemstones and periods of indentured servitude of their young for weapons and advanced technology from the Human settlers. The traded equipment played a role in a series of internal revolutions that changed Jarell society, but the conflicts never posed a threat to the Human settlements.
In the decades leading up to the Battle of Yavin, Oon Tien became more connected to the Kathol sector, and several large manufacturing complexes were built on the planet. The world also developed a large agricultural industry. When Oon Tien was taken over by the Galactic Empire, Moff Kentor Sarne made Governor Manon Flint the commander of the system. Sarne built three stardocks in orbit, each with the ability to service and repair capital ships up to 300 meters long. The docks were the main maintenance facilities for Sarne's forces and were the largest shipyards in the sector. When the Moff left the Empire after the Battle of Endor in 4 ABY and declared himself a warlord, Oon Tien became part of Sarne's holdings.
After the fall of Kal'Shebbol, the sector's capital, to New Republic forces in 8 ABY, Sarne was forced to retreat into the Kathol sector. Sarne ordered Governor Flint to defend the docks at all costs, or destroy them if the New Republic managed to invade the system. As the New Republic spread its influence throughout the sector, Oon Tien would prove to be one of the most troublesome planets because it was too heavily defended by Imperial loyalists to fall easily or quickly.
Oon Tien was the location of multiple settlements of both Human and Jarell origin. The three stardocks in orbit, which were the center of the Empire's fleet construction and maintenance programs in the sector, were the most notable installations on the planet. Because of the presence of industrial and agricultural based corporations, Oon Tien had large manufacturing and farming complexes on the surface.
Oon Tien was described in The DarkStryder Campaign, a supplement for Star Wars: The Roleplaying Game by West End Games.