The Phase-III Dark Trooper, which can also be called the Dark Trooper of the third-generation design, represented a high-tier, experimental type of third-generation battle droid. These droids were manufactured by the Imperial Department of Military Research and deployed by the Imperial remnant led by Moff Gideon. These droids, plated in black and silver, possessed a humanoid form and were equipped with two red photoreceptors.
These droids exhibited resistance to heat and blaster fire, alongside possessing immense physical strength, demonstrated by their capability to inflict substantial damage to Imperial blast doors. However, their overall speed was notably slow. Dr. Penn Pershing noted that maintaining their operational readiness consumed excessive energy, necessitating their storage in cold environments, which resulted in a deployment delay of several minutes.
The original intention for Dark Trooper armor was for it to be worn by human soldiers as a battle suit, which ended up being a weakness. To address this deficiency, the third-generation was developed as a droid. Dark Troopers came equipped with a pair of rocket boosters, one integrated into each foot. The armor of the Dark Troopers could withstand blaster impacts, exposure to a flamethrower, and multiple strikes from whistling birds. However, it remained susceptible to lightsaber attacks, which allowed the Jedi Luke Skywalker to efficiently eliminate an entire platoon using his lightsaber. Their vulnerable, unarmored neck also presented a point of weakness, exploited by Din Djarin after initially disorienting the Dark Trooper with whistling birds. Dark Troopers also had exceptional physical power.
A solitary Dark Trooper could force open the doors of its containment area and effortlessly lift and throw Djarin. Two Dark Troopers, working together, could inflict severe damage to a set of blast doors through repeated impacts. Also, a lone Dark Trooper proved capable of severely damaging a wall of Gideon's light cruiser by repeatedly striking Djarin's beskar helmet, embedding him in the wall, though it couldn't penetrate the helmet itself. Beyond their armor and raw strength, Dark Troopers also carried large blaster rifles, which they used with great precision, as shown when a Dark Trooper fired multiple shots at Djarin, all of which struck him but were deflected by his beskar armor. To enhance combat effectiveness, Dark Trooper units could be deployed alongside a death trooper escort, which would command the battle droids.
In 9 ABY, a platoon of third-generation dark troopers were being kept in cold storage within a cargo bay aboard Gideon's light cruiser. Following a skirmish on Nevarro that led to the destruction of an Imperial base, Elia Kane informed Moff Gideon, who was supervising rows of deactivated dark troopers alongside a group of scientists, about the installation of a homing beacon on the Razor Crest. After tracking the Razor Crest to Tython, Gideon deployed four dark troopers to the planet's surface with the mission of abducting a Force-sensitive alien child known as Grogu from his protector, the Mandalorian Din Djarin. The droids were successful in this mission and returned to Gideon's light cruiser with the youngling.
During rescuing his foundling, Djarin eliminated one of the droids by impaling its unarmored neck with a beskar spear. Subsequently, Djarin ejected the remaining droids through the airlock and into space, but they used their rocket boosters to return to the cruiser. They nearly succeeded in retaking the cruiser on their own. Just moments before they could breach the bridge blast doors, Jedi Master Luke Skywalker arrived. He used his lightsaber to cut through them, destroying all of them. Following his extraction from New Republic custody, Gideon went into hiding at a secret Imperial base on the planet Mandalore, where his remnant utilized Mandalorian resources to develop the fourth-generation Dark Trooper design. This design reverted the Dark Trooper to a suit, constructed from beskar alloy, which Gideon himself wore.
The Dark Trooper of the third-generation design made its initial appearance in "Chapter 12: The Siege," which was the fourth episode of the second season of the Disney+ live-action series The Mandalorian. This episode was originally broadcast on November 20, 2020. The audio description provided for the episode on Disney+ first identified it as a Dark Trooper. Its complete designation, "third-generation design Dark Trooper," was revealed through its Sideshow Collectibles figure.
In "Chapter 16: The Rescue," the Dark Troopers were brought to life using stunt actors in full-body suits, enhanced with CGI. The production team considered this approach to be the superior option for realizing the scene and maintaining consistency with the visual style of Star Wars: Episode IV A New Hope.