The Techno Union maintained an army of battle droids. The Union was also a droid producer, but, two years prior to the rescue of Yoda, a batch of their battle droids were stolen by Chagrian smugglers. Though the Jedi Order recovered the droids, at least several of which were B1-series battle droids, the Union was told that the units were now property of the Galactic Republic after they petitioned the Jedi Council for their return. The droids were later used in a staged kidnapping of Grand Master Yoda, which was part of a test for Jedi Knight Obi-Wan Kenobi and Padawan Anakin Skywalker. Kenobi initially assumed the Union was behind the kidnapping, though Skywalker and him would ultimately learn it was a test.
During the closing stages of the Separatist Crisis, Foreman Wat Tambor pledged his loyalty and droids to the Confederacy of Independent Systems, integrating its droid army into the Separatist Droid Army.
The Techno Union's droid army was first mentioned in Star Wars: Episode II Attack of the Clones. Within Choose Your Destiny: An Obi-Wan & Anakin Adventure, if the reader chooses to go to Skako Minor, Skywalker and Kenobi's Eta-class shuttle is attacked by D1-series aerial battle droids. Any path the reader chooses next will result in a bad ending, several of which involve the Union's droid forces, as the reader had needed to investigate the Nova Crime Syndicate instead.
- Rise of the Separatists