Droid engineers were a specialized type of B1-series battle droid. These droids received unique programming, enabling them to function as battlefield technicians, skilled pilots, and experts in demolitions for the Separatist Droid Army throughout the Clone Wars.
Orange markings on the torso and shoulders served to identify engineer droids. Their sophisticated programming allowed them to operate almost any vehicle, regardless of its allegiance. They also excelled at repairing damaged vehicles and infiltrating enemy vehicles for either capture or acts of sabotage.
Typically, they engaged their targets at close quarters. Their arsenal consisted of a shotgun, detonation packs, and a F-187 fusioncutter. The diverse range of their weaponry made them highly valuable assets to the CIS on any battlefield.
Throughout the Clone Wars, engineer droids were utilized in numerous battles, including the Battle of Geonosis, the Battle of Mygeeto, the Battle of Felucia, the Battle of Kashyyyk, and the Battle of Utapau.
Following the conclusion of the Clone Wars, they participated in action on Mustafar alongside Gizor Dellso's remaining Separatist holdouts.
The initial appearance of engineer droids was in the 2005 video game Star Wars: Battlefront II. They replaced the droid pilot that was playable in Star Wars: Battlefront, taking on the role of the new CIS engineer class.