Null - class Advanced Recon Commando Numbering only six , the Null - class Advanced Recon Commandos were the first clones of Jango Fett created by the Kaminoan cloners , and the prototypes for the Grand Army of the Republic . They were deemed a failure by the Kaminoans and were not put into mass - production . They were saved from termination by Mandalorian mercenary Kal Skirata who later adopted all of them . All of the Nulls were named after Mandalorian warriors . History . The Kaminoans attempted to enhance the Fett genes : the initial production run produced six " uncommandable " young clones . They were designated Null - class and slated for termination , and they were saved from destruction by Kal Skirata , a Mandalorian training sergeant hired by Jango Fett to train clone commandos . The next batch of clones , 100 of them , were designated the Alpha - ARCs and trained by Fett himself . Training . Kal volunteered to train them as " black ops " commandos , named them , and taught them their Mandalorian heritage — sequestered from the other clones throughout their training . Even before two years of age , Ordo and his Null brothers had already undergone flash instructions and live ordnance tests , obtaining immeasurably high scores . After completing their accelerated growth they trained in Mandalorian military and survival combat to kill and destroy by any means possible . During training , the Nulls also endured near - death " training " torture to become resistant to interrogation . Kal taught his clone troopers an interrogation resistance technique of shutting out reality to become someone who was not being interrogated . This technique could be done by visualizing putting the pain and fear in a box , by concentrating on its physical reality so minutely that it fragmented and ceased to register , by imagining that one were somewhere else , or by focusing on the next moment one could bear to think about — the next meal , second or step , time after time until the ordeal ended . They also had special training for essentials of warfare such as assassination , black ops , anti - terrorism , covert ops , espionage , slicing , and medicine . Kal furthered their training , teaching them how to handle a wide variety of weapons : from blaster rifles to Verpine sniper rifles and hand - to - hand combat . Later in their training , they learned the skills of maneuvering in zero - g . Special training . They received special training that allowed them to act without thinking ; they claimed that it resembled the Jedi ' s use of the Force . Life during training . Under Kal ' s supervision , the Nulls were separated from the other clones throughout their training . The other clones only ever saw the Nulls around Tipoca City when they were stealing equipment or sabotaging systems . Darman of Omega Squad remembered the Nulls scaling the supports of the huge domed ceilings , swinging around hundreds of meters above the floor , and placing blaster fire to within centimeters of the Kaminoan technicians . Fett ' s unaltered clone son Boba Fett angered the Nulls by saying that his father could beat Kal whenever he wanted . Ordo retaliated by sticking Boba ' s head down a refresher . Under Skirata ' s supervision they learned to use their fierce independence , innate creativity , and physical superiority with their training in advanced combat , weapons and vehicles to become virtual one - man armies . The Null ARCs were quite unpredictable by clone standards , loyal only to Skirata and other Nulls . Genes . Early during the clone army ' s development , Jango Fett and his Mandalorian military advisers advocated the creation of clones capable of handling covert missions too delicate for the standard units . Before the clones ' gestation , the Kaminoans changed Fett ' s DNA to ensure the dominance of behavioral genes that emphasized such qualities as loyalty , aggression , and discipline lest the clones act too independently . To achieve the desired results , the Kaminoans altered the clones ' aging process : each null would age at twice the rate of regular human beings . At the age of ten , a null would resemble Jango Fett in his early twenties and therefore was fit and prepared for combat . Their genetic structure gave them greater intelligence , better perception , and eidetic memory — allowing perfect photographic recall . During training , their intelligence tests scored thirty - five percent higher than other commando types and developed immeasurably high scores in training . The intense training and genetics gave them mental capabilities beyond that of standard clones . Their physiology was greatly improved : they were stronger , faster , and heavier than basic clone troopers . During training each clone developed Jango Fett ' s own Concord Dawn accent and speech patterns , just like the flash - learned standard clone troops . When the Kaminoans began cloning , they produced twelve prototypes , designated as Null - class Advanced Recon Commandos . Their extreme physiological modifications killed half of the prototypes during gestation . The " enhancements " to the Fett genome handicapped the survivors with erratic behavior and an inclination toward disobedience , making their loyalties unpredictable . Kal Skirata , a Mandalorian warrior who had been brought to Kamino to assist in the training of a special unit , concurred with the Kaminoans ' rationale behind " modified " troopers ; an " unaltered " Jango Fett was not the ideal infantry soldier . Disappointed with the unsatisfactory results of their wayward creations , the Kaminoans deemed 12 of the first 100 prototypes complete failures and intended to kill them . Kal Skirata ' s intervention , along with Fett ' s support , saved the clones . Skirata was charged with training the prototypes as intelligence units . Due to the Kaminoans ' genetic tinkering , the Nulls had very intense loyalties , and were loyal only to Kal Skirata . Among the modifications ' side effects were high sensitivity to minute personal details , a peckish appetite , and a sweet tooth , which Skirata theorized might be due to their maturation and the metabolic need to fuel their rapid aging . Overview . The Null ARCs were also known as Skirata ' s private army . The Nulls and Kal Skirata were reluctantly tolerated in the Grand Army , if only to ensure their cooperation during the war , because they had unique skills that their brethren lacked . The Null ARC Troopers worked in the Special Operations Brigade of the Grand Army . All Null ARC ' s were officers , except for Null - 12 who when asked why he was only a sergeant by one of the Omega Squad commandos , A ' den replied , " I preferred to be an NCO . If it ' s good enough for " Kal ' buir " , it ' s good enough for me . " Two Clone Intelligence units , Null - 6 and Null - 10 , were the troopers who located General Grievous ' s hiding place on Utapau near the end of the Clone Wars . The information was sent to Kal Skirata first and the intel was traced to the Supreme Chancellor ' s Office . Since the trace was obvious Skirata withheld the information from his superiors pending an investigation when a diplomatic package was received from Utapau informing the Senate of Grievous ' s location . Though they worked for the Grand Army of the Republic , Kal Skirata had them keep alert for evidence leading to the location of Kaminoan Chief Scientist Ko Sai , so Skirata could find out how to decelerate the aging process to give any clone a full life span . The experience of developing Null ARC troopers contributed much in the production of the Alpha - class Advanced Recon Commando s . During the Clone Wars , the Null - class and Alpha - class ARCs harbored grudges against each other . Whereas the Alpha - class ARCs saw the Nulls as an embarrassment and shame to Jango Fett ' s legacy of a fully Republic - loyal clone army , the Nulls viewed the Alpha - class ARCs as even more stubborn than Jango and often referred to Alpha - class ARCs as " Alpha Planks , " nothing special , ordinary ARC troopers . The highest ranking Null , Captain Ordo , managed to retain a professional relationship with Alpha Captain Maze , although the two had originally disliked each other . Known operations . Null ARC troopers While the other six Nulls died before even being recognizable as embryos , Skirata ' s thoughts during the capture of Ko Sai reveal that he did name all twelve of them .