Rail - class Advanced Recon Commando The Rail - class Advanced Recon Commando was a post - Galactic Republic generation of ARC troopers that was secretly bred by the Kaminoan scientists in a plot to liberate Kamino from the rule of the Galactic Empire . Unlike the clone troopers that served in the Clone Wars before becoming Imperial stormtroopers , the Rail - class ARC troopers were trained to have absolute loyalty to their Kaminoan creators instead of Emperor Palpatine . Created to compliment Kamino ' s army of Anti - Imperial clone troopers as an elite force , the ARCs were stationed within the Tipoca City Cloning Facility to protect the Kaminoans ' precious batches of young clones that were still being developed to fight the Empire . When the Empire learned of Kamino ' s plans for insurrection , the Sith Lord Darth Vader dispatched a special detachment of the 501st Legion , under the command of the bounty hunter Boba Fett , to Kamino with orders to annihilate the entire army of rebel clones . Thus , the Rail - class ARC troopers made their first and last stand alongside the Anti - troopers at the Kamino uprising in the year 12 BBY . History . Kamino ' s Secret Clone Army . Following the rise of the Sith Lord Darth Sidious as Emperor of the galaxy , he quickly consolidated his Galactic Empire with an iron fist . Paving the way for Imperial rule were the Imperial stormtroopers , clones of the late bounty hunter Jango Fett that served as the Galactic Republic ' s clone troopers prior to the Emperor ' s ascendancy to absolute power . It was then that the Kaminoans found their homeworld placed under Imperial occupation by their own creations , no less . Having made the mistake of indoctrinating the original Fett clones with absolute loyalty to the Republic , and thus the Empire , the Kaminoans sought to rectify their error by discreetly breeding a new clone army that was completely obedient to their Kaminoan creators . While the majority of the army was composed of Anti - trooper s , a special force of elite soldiers were created to compliment the regular soldiers . Hence , the Kaminoans engineered a new generation of Advanced Recon Commandos — the " Rail - class " ARC troopers . Under the observation of the Kaminoans , the Rail - class ARCs and the rest of the rebel clones were grown and trained for nearly a decade . The Rail - class ARC troopers were equipped with the ARC - variant Phase I armor , which included the command pauldrons and kamas . Their primary weapon was the chainguns . The Uprising on Kamino . Approximately twenty years after the Kaminoans created the first clone army for the Republic , the Sith Lord Darth Vader sent the 501st Legion to destroy the rebel clones and bring Kamino back into line . The 501st ' s mission commander was the bounty hunter Boba Fett , who also happened to be a clone of Jango Fett . While the Anti - troopers defended Tipoca City ' s outer perimeter , the Rail - class ARC troopers remained within the cloning facility to protect the batches of undeveloped rebel clones . Despite their fast growth and training , the Anti - troopers proved to be no match against Fett and the battle - hardened stormtroopers of the 501st Legion , many of whom were veterans of the Clone Wars . After storming the facility , Fett and his stormtroopers were suddenly engaged by the Rail - class ARC troopers , some of whom tried to take the fight outside and prevent the Imperials from breaching the Tipoca City . Their efforts failed , however , and the life support systems were destroyed , thus aborting the unborn Anti - troopers before they had a chance to fight . With the rebel Kaminoans ' capabilities to defend the city or grow another clone army severely diminished , they opted to escape from Kamino before the battle was completely lost . In the meantime , the last of the Rail - class ARC troopers joined the remaining Anti - troopers as they desperately fought against their relentless Imperial clone brethren . Though they battled hard , Fett and the 501st stormtroopers succeeded in crowding the rebel clones out onto the platforms where they were exterminated to the last clone . With the death of the Kaminoan insurgents that bred the rebel clone army , the Rail - class ARC troopers perished along with the Anti - troopers and the " " clone rebellion " " not only ended in failure , but would never be publicly known since all information regarding the Kamino Uprising became highly classified . Behind the scenes . Rail - class ARC troopers could be identified if a player targeted one of the chain - gun wielding troopers on " " during the level " Kamino : Changing of the Guard " , an ' unofficial ' clone revolution .