Droidekas, alternatively referred to as destroyer droids (or simply destroyers), and humorously nicknamed rollies within clone trooper slang, represented a specific model of battle droid. These droids were first deployed by the Trade Federation during the Invasion of Naboo, and later saw service with the Confederacy of Independent Systems throughout the Clone Wars. The Colicoids of Colla IV were responsible for their manufacture, and the droidekas were engineered to be exceptionally lethal, with the primary function of eliminating enemies with extreme force. They possessed the ability to transform, curling into a spherical shape for rapid movement (up to 75 kilometers per hour), or deploying on three legs, activating a shield generator, and engaging targets with weaponry. Prior to the events of the Invasion of Naboo, the Jedi Master Qui-Gon Jinn and his Padawan Obi-Wan Kenobi were confronted by droidekas aboard a Droid Control Ship.
Encased in bronzium plating, droidekas were armed with a variety of both protective and offensive systems. Notably, they utilized dual repeating blaster cannons and personal deflector shield generators. This meant that massed clone trooper assaults were often decimated by the droideka's rapid-fire weaponry, leaving few options for the clones unless they could bypass the shield with an EMP or call in artillery support. Some destroyers were referred to with he/him pronouns while others were referred to with she/her. Moreover, the pronoun it/its could also be used for a droideka.
The shields of a droideka were remarkably resilient, capable of easily withstanding or diverting high-speed, short-range attacks, thereby rendering blasters or other sidearms ineffective. The droideka's capacity to fire through its shield was due to its polarized nature, which allowed the droid's blaster projectiles to pass through while blocking incoming objects. Most handheld weapons lacked the necessary power to penetrate this defense. Despite their formidable nature, droidekas possessed vulnerabilities that could be exploited for their destruction; they had a blind spot to the rear, and their shields were ineffective against slow-moving, stationary objects. Coordinated rear attacks, combined with a diversion and a precisely thrown Electro Magnetic Pulse grenade, proved to be a highly successful strategy. Another method for neutralizing a droideka involved crushing it with a substantial, heavy object.
During the Battle of Naboo, droidekas carved paths through the Gungan ranks, employing their deadly repeating blasters, and subsequently targeted the shield generators carried by the Fambaa. Later, they were integrated into the Separatist Droid Army during the Clone Wars, fighting against the forces of the Galactic Republic. Following the massacre of the Separatist Council by Darth Vader, the droidekas were deactivated.
In the aftermath of the war, a droideka known as "The Unwinder" achieved prominence as a champion within a gladiatorial arena. Another droideka was discovered in a scrap yard managed by the Bidvel and [Davil], and was activated by C1-10P, ultimately saving the droid from the two scavengers. After a B2-series super battle droid inquired about their next course of action, C1-10P proposed the formation of a group dedicated to assisting other droids. On the planet Koboh, droidekas and other former Separatist units were reprogrammed and used as soldiers by the Bedlam Raiders. During the Galactic Civil War, the Droideka Oppressor and Droideka Sentinel variants were utilized by smugglers, as well as by the Alliance to Restore the Republic and the Galactic Empire. At least one droideka served as a security droid on Quarantine World III, pursuing Doctor Chelli Lona Aphra when she attempted to steal the Triple-Zero protocol personality matrix. Aphra later reprogrammed a droideka mark one, Dek-Nil, transforming him into a probability droid. The Scarabi, a mercenary group, employed a droideka to safeguard one of their safe houses.
During the conceptual design phase of the droideka, Doug Chiang did not initially consider its walking capabilities; he envisioned it solely as a rolling unit that would remain stationary when firing, essentially functioning as a static weapons platform. However, George Lucas desired the droideka to embody the characteristics of a gunslinger, owing to its prominent dual blasters. Consequently, the decision was made for the unit to be capable of walking. The challenge of animating the droideka's unfolding and walking motions fell to Hal Hickel of Industrial Light & Magic, who faced considerable difficulty in creating a plausible walk cycle for a design that was not originally intended for such movement.