The colossal superweapons known as World Devastators – also referred to as World Smashers, World Sweepers, Planet Smashers, or City Eaters – represented an evolution of the Imperial Leviathan. Equipped with formidable tractor beams, they possessed the capability to inflict catastrophic damage upon entire planets. These destructive machines were conceived by Umak Leth and utilized by the Dark Empire under the command of the resurrected Emperor Palpatine.
While the question of whether World Devastators surpassed the Death Star in sheer destructive power remains open for debate, their efficiency was undeniable. Unlike the Death Star, which could only obliterate planets, World Devastators could exploit the resources of targeted worlds to benefit the Empire. The primary operational mode of a Devastator involved landing on a planet's surface. Once there, its powerful tractor beam projectors would literally dismantle the planet, earning them the moniker "planet killers." The World Devastators' operational model bore similarities to the Star Forge, which likewise extracted materials from nearby celestial bodies.
The extracted planetary materials were then repurposed as fuel for the Devastator and as feedstock for its internal foundries. These foundries could produce starships, starfighters, and droids, which were immediately deployed into combat. Given sufficient resources, these internal factories could manufacture anything from a starfighter or speeder up to a medium-sized cruiser. This operational paradigm was akin to the Star Forge, a vast automated shipyard created by the Rakatan Infinite Empire that also harvested materials from a nearby astronomical object to construct military hardware.
A central droid brain controlled each World Devastator; sentient crew members were present to supervise production and manage navigation or weapons systems. The droid brain was responsible for the creation of new weapons, and it was programmed with a vast library of ship designs and specifications, enabling it to produce a diverse range of vessels tailored to any combat scenario.
Furthermore, the factories could also prioritize upgrades to the World Devastator itself; a portion of the raw materials generated in the molecular furnace was allocated for enhancements to the main structure. Due to these unique customizations, no two "mature" World Devastators were truly identical. Given enough time and resources, the World Devastators even possessed the capability to manufacture additional World Devastators.
The shields of these machines were so robust that even concentrated turbolaser fire proved ineffective against them. Moreover, any contact with an enemy vessel often resulted in the World Devastator consuming that ship.
Three smaller Devastators had their shield generators mounted on their exterior hull, rendering them vulnerable to starfighter attacks. If two of their four "legs" were destroyed, the Devastator would lose power and collapse onto the surface.
The Devastator design underwent development at the Maw Installation research facility prior to the completion of the first Death Star, alongside other superweapons like the Sun Crusher. However, they were secretly constructed in Imperial shipyards, with only a general outline of the project mentioned in the Imperial Handbook: A Commander's Guide. Crix Madine believed around 4 ABY that they never progressed beyond the planning phase.
The earliest operational World Devastators were deployed in the Borderland Regions around 10 ABY, where rumors of terrifying "city-smashers" devastating worlds reached the New Republic. Shortly thereafter, World Devastator fleets materialized around numerous Republic-affiliated worlds. Admiral Comeg's fleet stationed in the Core Worlds possessed a prototype World Devastator, Silencer-7.
They faced significant resistance during the Battle of Mon Calamari, where they were deployed against the aquatic world of Dac, which served as the New Republic's temporary capital following the remnants of the Empire's recapture of Coruscant.
Mon Calamari had previously been targeted for destruction by the first Death Star. With the destruction of that battle station—and its successor—it appeared that Mon Calamari was safe from the Empire's grasp. However, when the resurrected Palpatine launched his assault, Mon Calamari became the initial target of his World Devastators.
Led by the colossal Silencer-7, the Devastator squadron descended upon Mon Calamari, crushing the floating cities and shipyards, and feeding their factories in anticipation of a New Republic counterattack. These foundries produced various assault vehicles, including TIE/D fighters and wavewalkers. Admiral Ackbar dispatched a New Republic fleet to confront the devastating attack on his homeworld, including the captured Imperial-class Star Destroyer Emancipator and a squadron of X-wings. Yet, nothing the New Republic deployed could halt the Devastators' relentless advance.
The World Devastators launched automated droid TIE fighters against the Republic starfighters, and one Devastator moved into orbit to directly confront the Emancipator. The Devastator consumed the Star Destroyer in its molten furnace, forcing the crew to evacuate or become the metal monster's next meal. Fortunately, the Rebels had reinforcements available, and dispatched V-wing and E-wing squadrons to the surface to engage the Devastators. Rogue Squadron attacked and disabled three smaller Devastators. The squadron's actions prevented the destruction of nearby Mon Calamari cities.
During the battle, the assault weapons suddenly ceased functioning. While the Alliance attributed this to the Imperial commander's incompetence, this unexpected turn of events was actually part of a larger plan. Luke Skywalker had infiltrated the highest levels of Imperial command by feigning allegiance to Palpatine.
From his position as Supreme Commander of the Imperial Forces, Skywalker was able to deactivate the Devastators. However, their internal factories continued to produce wavewalkers and TIE/D fighters, forcing the New Republic to devise a new strategy while battling the Imperial vehicles.
Luke Skywalker smuggled a wealth of Imperial data into Rebel hands via the astromech droid R2-D2. The little droid was able to decode the data and create a new code that would interfere with the Devastators' droid brains. The virus proved remarkably effective; the Devastators turned on each other, leaving only destroyed husks in the water world's oceans. The New Republic captured at least one World Devastator, as one was observed among the fleet surrounding Da Soocha V, consuming derelict spacecraft. All Republic-held Devastators were later scrapped following public outcry.
The destruction of the World Devastator fleet appeared to have little impact on Emperor Palpatine, who soon unleashed an even more terrifying weapon: the Galaxy Gun.
Initial plans included super-sized "Momma Devastators" in Star Wars: Dark Empire, but the concept never progressed beyond the conceptual artwork stage.
The World Devastators in the video game Star Wars: Rogue Squadron could be destroyed by precision strikes from Rogue Squadron's V-wing airspeeders. Given the Dark Empire depiction of Devastators as virtually indestructible, this raises questions about the canonicity of destructible Devastators (which were notably smaller in Rogue Squadron than in the comics). It remains unclear whether the V-wings' ability to destroy World Devastators, a key element of that game level, is a non-canon game mechanic or an indication that some of the smaller Devastators deployed at Dac were vulnerable to starfighter or airspeeder attacks. The game's strategy guide suggested the latter interpretation.
In the online game Death Star Designer, players can incorporate a World Devastator into their Death Star design.