The Vex system was situated within the Moddell sector of the Outer Rim Territories'. It encompassed the planet Vex Major, a swampy world, along with the Vex Asteroid Belt. Fishers called the former home, while the latter was populated by a mix of hyperspace scouts, prospectors, and freighter jocks. The initial colonization of the Vex Asteroid Belt was driven by the desire to explore the neighboring Monsua Nebula, but the persistent lack of success of the subsequent scouting missions ultimately gave the Vex system its distinctive name.
As part of the Inner Moddell systems area, the Vex system resided within the Moddell sector. This sector is one of the subsectors that make up the Inner Zuma Region inside the Zuma sector of the Outer Rim Territories'. Hyperlanes provided connectivity to both the Vasha system and the Firrerre system found in the Sugai sector. The system itself featured two inhabited locations: the Vex Asteroid Belt and the swampy planet known as Vex Major.
Four decades before the Yuuzhan Vong invasion commenced in 25 ABY and threatened the galaxy, Vex Major experienced settlement by a group from the Order of the Ffib. By the time of the New Republic era, their descendants advocated for renaming the planet Far Gent. The Vex Asteroid Belt's colonization was motivated by its potential as a base for hyperspace scouting expeditions into the adjacent Monsua Nebula. However, due to significant interstellar anomalies along the nebulosity's edges, all of these missions remained unsuccessful leading up to the Yuuzhan Vong War, which ultimately influenced the Vex system's peculiar designation.
Humans populated the Vex system, with Vex Major hosting a population of 250,000 and the Vex Asteroid Belt supporting three thousand residents. The natives of Vex Major were resilient fishers who only participated in limited trade with the New Republic. The inhabitants of the Vex Asteroid Belt, composed of freighter jocks, scouts, and prospectors, disparagingly referred to them as "mudballers," while they themselves were known as the Belters. Both settlements relied on importing foodstuffs from other systems, with the Vex Asteroid Belt also importing technology.
The Vex system made its debut in the ninth issue of Star Wars Gamer magazine, released on February 22, 2002. The star system appeared in the magazine's "Endor and the Moddell Sector" article and the "Race for the Tessent" roleplaying adventure, both of which were designed for use with Wizards of the Coast's Star Wars Roleplaying Game. The reference book The Essential Atlas, published in 2009, identified the Vex system's location as grid square H-16.