Null-class Advanced Recon Commando

The Kaminoans sought to improve the Fett genes, and the first production resulted in six young clones who were "uncommandable." These clones were labeled as Null-class and were scheduled for termination, but Kal Skirata, a Mandalorian training sergeant employed by Jango Fett to train clone commandos, saved them from destruction. The subsequent batch of clones, consisting of 100 individuals, was designated as the Alpha-ARCs and received training directly from Fett.

Kal volunteered his services to train them into "black ops" commandos. He provided them with names and educated them about their Mandalorian heritage, keeping them isolated from the other clones during their training. Even before reaching the age of two, Ordo and his Null brothers had already completed flash instructions and live ordnance tests, achieving remarkably high scores. After their accelerated growth phase, they underwent training in Mandalorian military tactics and survival combat, learning to kill and destroy by any means necessary.

During their training, the Nulls were also subjected to near-fatal "training" torture to build resistance to interrogation. Kal taught his clone troopers a technique to resist interrogation by detaching from reality, effectively becoming someone other than the person being interrogated. This method involved visualizing the pain and fear as being contained in a box, focusing so intently on its physical reality that it fragmented and ceased to register, imagining oneself in a different location, or concentrating on the next bearable moment—the next meal, second, or step, repeatedly until the ordeal concluded.

They also received specialized training in essential warfare skills, including assassination, black ops, anti-terrorism, covert operations, espionage, slicing, and medicine. Kal further enhanced their training by teaching them how to use a wide range of weapons, from blaster rifles to Verpine sniper rifles, as well as hand-to-hand combat. Later in their training, they acquired the skills necessary for maneuvering in zero-gravity environments.

Under Kal's guidance, the Nulls remained separate from the other clones throughout their training. The other clones only encountered the Nulls in the vicinity of Tipoca City when they were either stealing equipment or sabotaging systems. Darman of Omega Squad recalled instances of the Nulls scaling the supports of the massive domed ceilings, swinging hundreds of meters above the floor, and precisely placing blaster fire within centimeters of the Kaminoan technicians. Boba Fett, Jango's unaltered clone son, provoked the Nulls by asserting that his father could defeat Kal at any time. Ordo responded by forcefully submerging Boba's head in a refresher.

Under Skirata's tutelage, they learned to leverage their strong independence, inherent creativity, and physical superiority, combined with their training in advanced combat, weapons, and vehicles, to become virtually unstoppable one-man armies. The Null ARCs displayed a level of unpredictability that was uncommon among clones, remaining loyal only to Skirata and their fellow Nulls.

Early in the development of the clone army, Jango Fett and his Mandalorian military advisors advocated for the creation of clones capable of handling covert missions too sensitive for standard units.

Before the clones' gestation period, the Kaminoans altered Fett's DNA to prioritize behavioral genes that emphasized qualities like loyalty, aggression, and discipline, ensuring that the clones would not act too independently.

To achieve the desired outcomes, the Kaminoans modified the clones' aging process: each Null would age at twice the rate of a typical human. By the age of ten, a Null would physically resemble Jango Fett in his early twenties, making them fit and ready for combat.

Their genetic makeup granted them enhanced intelligence, improved perception, and eidetic memory, allowing them to perfectly recall photographic images. During training, their intelligence test scores were thirty-five percent higher than those of other commando types, and they achieved remarkably high scores in training exercises. The combination of intense training and genetics resulted in mental capabilities that surpassed those of standard clones.

Their physiology was significantly enhanced: they were stronger, faster, and heavier than basic clone troopers.

During training, each clone developed Jango Fett's Concord Dawn accent and speech patterns, mirroring the flash-learned standard clone troops.

When the Kaminoans initiated the cloning process, they produced twelve prototypes, designated as Null-class Advanced Recon Commandos. The extreme physiological modifications resulted in the deaths of half of the prototypes during gestation. The "enhancements" to the Fett genome caused the survivors to exhibit erratic behavior and a tendency toward disobedience, making their loyalties unpredictable. Kal Skirata, a Mandalorian warrior brought to Kamino to assist in the training of a special unit, agreed with the Kaminoans' rationale for "modified" troopers, stating that an "unaltered" Jango Fett was not the ideal infantry soldier. Disappointed by the unsatisfactory results of their wayward creations, the Kaminoans deemed the initial 12 prototype clones complete failures and intended to eliminate them.

Kal Skirata's intervention, along with Fett's support, saved the clones. Skirata was tasked with training the prototypes as intelligence units. As a result of the Kaminoans' genetic manipulation, the Nulls developed intense loyalties, exclusively to Kal Skirata.

Among the side effects of the modifications were heightened sensitivity to minor personal details, a picky appetite, and a preference for sweets, which Skirata speculated might be due to their maturation and the metabolic demands of their accelerated aging.

The Null ARCs were also known as Skirata's personal army. The Grand Army reluctantly tolerated the Nulls and Kal Skirata, primarily to ensure their cooperation during the war, as they possessed unique skills that their brethren lacked. The Null ARC Troopers served in the Special Operations Brigade of the Grand Army. All Null ARCs held officer ranks, except for Null-12. When asked by an Omega Squad commando why he was only a sergeant, 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 responsible for locating General Grievous's hiding place on Utapau towards the end of the Clone Wars. This information was initially sent to Kal Skirata and then traced back to the Supreme Chancellor's Office. Recognizing the obvious trace, Skirata withheld the information from his superiors pending an investigation, until a diplomatic package arrived from Utapau, informing the Senate of Grievous's location.

Although they served in the Grand Army of the Republic, Kal Skirata instructed them to remain vigilant for any evidence leading to the whereabouts of Kaminoan Chief Scientist Ko Sai, as Skirata sought to discover how to slow down the aging process and grant all clones a full lifespan.

The experience gained from developing Null ARC troopers significantly contributed to the production of the Alpha-class Advanced Recon Commandos. During the Clone Wars, the Null-class and Alpha-class ARCs harbored animosity towards each other. The Alpha-class ARCs viewed the Nulls as a source of embarrassment and a stain on Jango Fett's legacy of a fully Republic-loyal clone army, while the Nulls considered the Alpha-class ARCs to be even more stubborn than Jango, often referring to them as "Alpha Planks," implying they were nothing special and just ordinary ARC troopers. The highest-ranking Null, Captain Ordo, managed to maintain a professional relationship with Alpha Captain Maze, despite their initial dislike for each other.

• Galactic City spaceport hostage siege
• Mission to Kamino
• Mission to Coruscant
• Sabotage of Olanet Droid Factory
• Battle of Gaftikar
• Mission to Utapau

Null ARC troopers

• N-5 ("Prudii"), Lieutenant
• N-6 ("Kom'rk"), Lieutenant
• N-7 ("Mereel"), Lieutenant
• N-10 ("Jaing"), Lieutenant
• N-11 ("Ordo"), Captain
• N-12 ("A'den"), Sergeant

Skirata's reflections during Ko Sai's capture indicate that he named all twelve Nulls, even though the other six perished before reaching an identifiable embryonic stage.