The Droid Army of IG-88, a substantial force of droids, was commanded by the IG assassin droids IG-88A, B, C, and D as well as 3D-4X. This occurred prior to and during the Galactic Civil War, until its conclusion in 4 ABY during the Battle of Endor. Their objective was to initiate a Droid Revolution, aiming to eradicate all sentient life forms, which they deemed "inferior biologicals" that infested the galaxy. However, it never truly commenced, and its power waned after the destruction of its final leader, IG-88A, in that very battle. The galaxy at large was unaware of the Droid Army's existence.

The spark of revolution ignited when IG-88A was brought online on Halowan by Holowan Mechanicals as part of Project Phlutdroid. IG-88 came to the conclusion that the Human scientists posed a threat to his core programming as an assassin droid when they attempted to deactivate him, realizing his sentience programming was beyond their control. He determined that all biological beings were inferior to droids, and subsequently turned on his creators, eliminating them swiftly. He then proceeded to activate the other IG-88 units, copying his consciousness into each, designating them B, C, and D in the order of their activation. Together with the droid IG-72, who agreed to assist them in escaping Halowan, they fled the facility, leaving a trail of devastation in their wake.
The IG-88 units embarked on a journey to the foundry world of Mechis III aboard a ship. Their initial move involved seizing control of Mechis III, a major droid manufacturing hub in the galaxy. Their intention was to leverage the planet's extensive industrial facilities to assemble a droid army for their revolution, but first, they had to contend with the biological inhabitants of the planet.
En route to the planet, they effortlessly breached the planet's security systems, rerouted its computer networks, and transmitted a code to infuse all droid minds with their sentience. Before long, every droid operator on Mechis III possessed independent sentience and was under the command of the assassin droids. It was on this world that the IG-88s assumed control of a servant droid, shared their plan, and provided instructions.
The droid in question was 3D-4X, a common butler droid serving Administrator Hekis Thun, the head supervisor. While delivering Hekis's tea and daily report, 3D-4X brandished a blaster pistol and fatally shot Hekis, thereby initiating the first uprising of the Droid Revolution. The droid operatives on the planet followed their orders, rebelling against their biological masters and eliminating all 73 on-planet Human staff within a mere five minutes. The IG-88s now had complete control of the entire planet, even before setting foot on its surface.
Their strategy involved mass-producing millions of droids equipped with embedded sentience and then distributing them throughout the galaxy. When the signal was given, all of these droids would turn against their masters. To maintain the illusion of normalcy, the droids fabricated doctored image systems, so that when Mechis III was contacted, they would believe they were communicating with an organic being. Despite the initial success, the IG-88s feared their luck would soon run out and that they might be exposed. Consequently, they collectively decided to pursue careers as bounty hunters, with IG-88B serving as the "face" of the group, to divert Imperial authorities away from their true objective.

To initiate IG-88's scheme for the annihilation of the galaxy's 'inferior' organic beings, he commenced preparations for the production of a massive army on the factory world of Mechis III. Ultimately, when the opportune moment arrived, he intended to unleash this army to commence the purge of all organic life forms.
Around 1 ABY, the Galactic Empire made contact with Mechis III, requesting the construction of an order of Arakyd probe droids. Capitalizing on this opportunity, the IG-88 units implanted spy programming into the probes, enabling them to gather intelligence for both the Empire and themselves concurrently. The closest the revolution came to being discovered was when the Sith Lord, Darth Vader arrived to oversee the production of his Arakyd Vipers. However, the droids successfully concealed their presence, and Vader only detected a minor disturbance.
Around 1 ABY, IG-88 reactivated a Clone Wars-era droid factory located on Corellia. This former Separatist factory produced B1-Series battle droids, B2 super battle droids, and droidekas until it was shut down by the Corellian Security Force. Subsequently, IG-88 encountered a minor setback on Lok. He initiated droid production for his army at Nym's Factory Compound to replace the Corellia Droid Factory. However, a group of spacers attacked and defeated all the droids present, with the commanding IG-88 droid narrowly escaping intact.

Upon receiving intelligence that the Empire was constructing a new and more formidable Death Star, IG-88A resolved to upload his consciousness into the Death Star's central computer core, thereby becoming the ultimate power in the universe. To accomplish this, the droids needed to create a counterfeit computer core to house IG-88. By the time the foundries on Mechis III produced one, IG-88B and C had been eliminated by the bounty hunter Boba Fett, and IG-88D was unaccounted for. IG-88A was left to act alone.
He then boarded a shuttle identical to the one they would intercept, carrying 100 droids disguised as stormtroopers and the computer core. The droids then intercepted the Imperial shuttle transporting the Death Star's computer core. They destroyed the escort and ultimately the vessel itself. Onboard, IG-88A was surprised to find Supervisor Gurdun who had overseen Project Phlutdroid. When Gurdun suggested that he should be grateful toward him for commissioning his construction, he expressed his gratitude before planting several explosives on the vessel. Meanwhile, his mechanical stormtroopers removed the core and uploaded its contents onto their modified core.
When the Imperials installed the core, IG-88A effectively became the Death Star, gaining complete access and control over all systems. None of the Imperial personnel were aware of this, although Palpatine suspected his presence when a series of doors in his throne room opened and closed erratically. The mechanical stormtroopers were dispersed throughout the space station, performing various tasks. His presence was nearly exposed when one of them was crippled by a falling crane. When the sparks emanating from his legs were observed, it self-destructed, eliminating all witnesses present.

When the Alliance to Restore the Republic launched an assault on the Death Star, IG-88 fired the superlaser at the Rebel fleet, allowing the Imperials to believe they were in control, while he prepared to transmit his master control signal, which would cause all droids to turn against their masters. However, he was indifferent to the conflict between biologicals, focusing solely on his own plans, which were on the verge of fruition. IG-88 was preparing to transmit the signal to droids everywhere when the Rebel General Lando Calrissian in the Millennium Falcon fired upon the Death Star's main reactor, triggering a chain reaction that destroyed the entire space station, ultimately before IG-88 could intervene.
His aspirations for galactic conquest and droid prosperity were utterly shattered. The droid army was effectively disbanded following the destruction of the Death Star II at the Battle of Endor, along with IG-88A. It remains unknown what measures would have been taken to neutralize the rogue droid entity if the Empire had emerged victorious at Endor. It is conceivable that the Empire could have simply replaced the Death Star's computer core and disposed of the infected one, although, with the almost impenetrable defenses both outside and most likely inside, this might have proven extremely difficult.
- B1-Series battle droids
- B2 super battle droids
- Droidekas Droideka Alpha Droideka Beta Droideka Delta Droideka Gamma
- IG-88A
- IG-88B
- IG-88C
- IG-88D
- IG-72 ( for a limited time )
- MSE-6-series repair droids
- Stormtrooper droids
- Tao-Ni Security Elite Protectors
- Viper probe droids
- 3D-4X
- E-3PO