The Oseon Belt existed within the Oseon system, which was a part of the Centrality region in the Outer Rim Territories. Lando Calrissian, a gambler, once acquired ownership of a subtropical moon located within it by 10 BBY. However, thirteen years later, Zana Gatta, who was also a gambler, was banished from the Oseon system for allegedly violating the rules of the gaamja game during a competition held in the Oseon Belt.
This Oseon Belt resided inside the Oseon system, which itself was situated within the Centrality area. It was considered a component of both the Outer Rim Territories and the Slice. The Oseon Belt, in conjunction with the rest of the Oseon system, was positioned in grid square T-8 of the Standard Galactic Grid and was situated along a hyperspace route that provided a connection to Junkfort Station and Marleyvane. The Sanity Skip, another route, also linked the Oseon system with the Kessel system. A subtropical moon was one of the celestial objects found within the Oseon Belt.
No later than 10 BBY, the human gambler known as Lando Calrissian became the owner of the subtropical moon inside the Oseon Belt through winning a card game. During that year, Calrissian mentioned his acquisition of the natural satellite while playing sabacc with Han Solo, a thief, at the Lodge, a saloon located on the planet called Vandor. By thirteen years after that, the human gambler Zana Gatta participated in a gaamja game held within the Oseon Belt, which was observed by a friend of a Rodian. Gatta was subsequently expelled from the Oseon system for what appeared to be a violation of the game's regulations.
In the following cycle, a Rodian recounted Gatta's gaamja match in the Oseon Belt to Kay Vess, a thief.
The 2018 film Solo: A Star Wars Story, part of the Star Wars Anthology Series, marked the initial mention of the Oseon Belt. The companion reference book, Solo: A Star Wars Story The Official Guide, written by Pablo Hidalgo, presented its name as "Oseon belt." The Star Wars Legends continuity is where the origins of the Oseon Belt can be found. The Oseon system, filled with asteroids, made its debut in Lando Calrissian and the Mindharp of Sharu, the June 12, 1983 first novel in The Lando Calrissian Adventures trilogy by L. Neil Smith. The second novel in the trilogy, Lando Calrissian and the Flamewind of Oseon, published on September 12, 1983, established that this star system contained several asteroid belts. The original cover of that book, featuring an illustration by William Schmidt, also provided the first visual representation of the system's asteroid Oseon 6845.
Beginning with the 1996 Star Wars: The Roleplaying Game, Second Edition, Revised and Expanded rulebook, penned by Bill Smith for West End Games' Star Wars: The Roleplaying Game, and also Hidalgo's 1996 Second Edition of the 1989 The Roleplaying Game sourcebook Galaxy Guide 3: The Empire Strikes Back, Star Wars resources began to refer to the Oseon system's collection of asteroids as a more unitary object, introducing terms like the "Oseon asteroid belt," the "Oseon asteroid field," and the "Oseon belt." The Wizards of the Coast roleplaying game source article "A Campaign Guide to the Centrality," written by Michael Kogge and appearing in the fifth issue of the Star Wars Gamer magazine on July 24, 2001, was the first effort to reconcile these viewpoints by characterizing the overall object, which it called the "Oseon Asteroid Belt," as being composed of several smaller belts.