The IG-88s massacre their creators.
The revolution started when IG-88A was created and activated on Halowan by Holowan Mechanicals during Project Phlutdroid. IG-88 realized that the Human scientists were a threat to his primary programming as an assassin droid, when they tried to shut him down, after realizing that his sentience programming was too powerful to control. He decided that all biologicals were inferior to droids, and then turned against his creators and killed them within seconds. He then continued to activate the other IG-88's, copying his consciousness into each, and designated them B, C, and D in order of their activation. Then, together with fellow droid IG-72, who agreed to help them get off Halowan, they escaped the facility, carving a swath of destruction along the way.
The IG-88s took off on a ship towards the foundry world of Mechis III. Their first step was to take over the foundry world Mechis III, which was one of the Galaxy's largest droid manufacturers. They planned to use the planet's vast industrial complexes to construct a droid army for their revolution, but first they had to deal with the biologicals on the planet.
As they flew toward the planet in their ship, they simply sliced into the planet's security system, rerouted the planet's computer systems and transmitted a code to transfer their sentience into all droid minds. Before long all of Mechis III's droid operators, had sentience of their own, and were under the control of the assassin droids. It was here that the IG-88s took control of a servant droid, told it their plan, and instructed it what to do.
The droid in question was 3D-4X, a common butler droid for the head supervisor, Administrator Hekis Thun. While delivering Hekis's tea and daily report, 3D-4X pulled out a blaster pistol and shot Hekis dead, thus starting the first uprising of the Droid Revolution. The droid operatives on the planet followed their orders and rose against their biological masters, and killed all 73 on-planet Human staff within five minutes. The entire planet was now in the hands of the IG-88s, before they had ever step foot on its surface.
Their plan was to mass-produce millions of droids, with embedded sentience and then ship them out all over the galaxy. Thus, when the signal was given, all of these droids would turn on their masters. To make it seem as if nothing had occurred, the droids constructed doctored image systems, so that when Mechis III was contacted, they would think that they were talking to an organic being. All was going well, but the IG-88's feared that soon their luck would run out, and that they might be discovered. So they all agreed that they would take jobs as bounty hunters, with IG-88B as the "face" of the group, in order to lead the Imperial authorities away from their true objective.
A pair of droidekas serving under IG-88's droid army.
To begin IG-88's plans for the extermination of the 'inferior' organic beings of the galaxy, he began plans in producing a massive army on the factory world of Mechis III. Eventually, when the time would arrive, he would unleash this army to begin the purge of all organic beings.
Soon, around 1 ABY, the Galactic Empire contacted Mechis III, to construct an order of Arakyd probe droids. The IG-88's took this opportunity, and implanted spy programming into the probes, so that at the same time that the probes were working for the Empire, they were spying for them. The closest the revolution ever came to getting discovered was when the Sith Lord, Darth Vader came to oversee the production of his Arakyd Vipers. However, the droids masked their presence well, and Vader merely sensed a slight disturbance.
At some point around 1 ABY, IG-88 reactivated a Clone Wars-era droid factory on Corellia. The former Separatist factory produced B1-Series battle droids, B2 super battle droids and droidekas until it was shut down by the Corellian Security Force. Later, IG-88 suffered a slight setback on Lok. It began production of droids for its army in Nym's Factory Compound to replace the Corellia Droid Factory. However, a group of spacers attacked and defeated all the droids there, with the commanding IG-88 droid barely escaping intact.
The Second Death Star during the time of its construction.
When IG-88A received information that the Empire was building a new and more powerful Death Star, he decided to download his consciousness into the Death Star's central computer core and become the ultimate force in the universe. To do this the droids had to create a false computer core to store IG-88 in. By the time the foundries on Mechis III churned one out, IG-88B and C had been destroyed by the bounty hunter Boba Fett, and IG-88D was missing. IG-88A was on his own.
He then boarded an identical shuttle to the one they would intercept which carried 100 droids disguised as stormtroopers and the computer core. The droids then intercepted the Imperial shuttle carrying the Death Star's computer core. They destroyed the escort and eventually the vessel itself. Onboard, IG-88A was surprised to find Supervisor Gurdun who had overseen Project Phlutdroid. When Gurdun told him that he should be gracious toward him, for commissioning his construction, he thanked him before planting several explosives on the vessel. Meanwhile, his mechanical stormtroopers carried the core out and downloaded its contents onto their modified core.
When the Imperials installed the core, IG-88A literally became the Death Star, with complete access and control to all systems. None of the Imperial personnel knew, although Palpatine suspected his presence when a series of doors in his throne room opened and closed wildly. The mechanical stormtroopers were scattered throughout the space station doing various things. His presence was almost revealed, when one of these was crippled by a fallen crane. When the sparks coming from his legs were seen, it self-destructed, killing all the witnesses present.
IG-88 firing the first blast of the second Death Star's superlaser.
When the Alliance to Restore the Republic attacked the Death Star, IG-88 fired the superlaser at the Rebel fleet, letting the Imperials believe they were in control, while he prepared to transmit his master control signal that would cause all droids to turn on their masters. However, he could not care less about this war between biologicals, he was only concerned with his plans, which were about to come into being. IG-88 was now preparing to send out the signal to droids everywhere, when the Rebel General Lando Calrissian in the Millennium Falcon, shot at the Death Star's main reactor, causing a chain reaction which destroyed the entire space station, ultimately before IG-88 could do anything to stop them.
His plans for galactic conquest and droid prosperity were now utterly destroyed. The droid army was effectively dissolved after the destruction of the Death Star II at the Battle of Endor, and IG-88A with it. It is unknown what would have been done to stop the rogue droid entity if the Empire had been victorious at Endor. One would think the Empire could simply replace the Death Star's computer core and dispose of the infected one, though with the nearly impenetrable defenses outside (and mostly likely inside), this may have proven to be extremely difficult.
- The Essential Reader's Companion