Originally conceived by the Yovshin Swordsmen, Jar'Kai was a sword-fighting style that involved wielding two weapons simultaneously. A comparable technique, known as Niman, which also used two blades, was created by the Royale Macheteros serving the Kashi Mer monarchy. During the First Great Schism, Niman was embraced by both the Legions of Lettow, a group aligned with the dark side, and the Jedi Order. Subsequently, Niman evolved into the sixth form of Lightsaber combat, retaining its original designation.
Notably, the fourth form of lightsaber combat, Ataru, incorporated dual blades within its training practices. Ahsoka Tano achieved mastery in this form at a young age, while still a Padawan, a feat that would challenge even seasoned Jedi Masters.

The Yovshin Swordsmen's Jar'Kai style derived its name from a city located on Atrisia. This city, Jar'Kai, was also the place where the original Jar'Kai dueling sabers were manufactured. The Yovshin employed these weapons, which were specifically designed for dual-wielding.
The Kashi Mer's Royale Macheteros developed Niman, a dual-blade style named after the dual triumvirate of the Kashi deities. The Legions of Lettow, a group of Dark Siders responsible for the Jedi Order's First Great Schism, adopted this style. Following the Jedi's victory over the Legion, the Jedi Order embraced Niman, refining it into the sixth form of lightsaber combat, which retained the same name. Before the Order adopted Niman, some Jedi, such as Awdrysta Pina, who wielded a pair of Jedi katanas in combat, engaged in dual-blade combat. Many Jedi Knights and Sith Lords trained in Form VI with the intention of acquiring a basic understanding of dual-bladed combat, but very few ever fully mastered Niman.
Notable Niman dual-blade practitioners included Jedi Master Kavar, who used a shoto as his secondary weapon, and Exar Kun, a Jedi trainee who became a Sith Lord and occasionally wielded an additional weapon. However, few duelists practiced classic Niman, although the Jar'Kai tactic was widely used. Many Jedi and Sith were known to use a secondary blade in combat, but few did so consistently.

Dual-blade fighters, whether they were classical Niman duelists or individuals using the Jar'Kai tactic, were able to maintain a strong offense because the speed of attack afforded by two blades could overwhelm most opponents. A common tactic involved continuously attacking with one blade while using the other for defensive purposes, allowing the duelist to maintain their guard while attacking. However, both blades were commonly used for offensive purposes, creating a continuous wave of attacks.
Another advantage of Jar'Kai was that the two blades made it easier to defend against multiple opponents, as there were simply more blades to parry with. Asajj Ventress, a dual-blade practitioner, demonstrated this during her mission on Ruul, where she fought against up to three Jedi at once. Dual blades could also be used defensively or to compensate when fighting another opponent who used multiple blades, as demonstrated when Kit Fisto stole and used one of the blades of the cyborg General Grievous, whose mechanical body allowed him to wield up to four lightsabers at once.
The "Rising Whirlwind," which involved the duelist swinging their blades around their body to create a "whirlwind" of deadly attacks, and the "Twin Strike," in which both blades were swung in an arc toward the opponent in a powerful attack, are two well-known Jar'Kai techniques and maneuvers.
Jar'Kai, while a complete fighting system in itself, could be easily adapted to other styles. After beginning her training under Darth Tyranus, Asajj Ventress quickly incorporated Makashi techniques into her Jar'Kai practice. Because Makashi was Tyranus's preferred form, Jedi Master Luminara Unduli was able to recognize his training techniques in Asajj's fighting abilities, and she made this observation. Mace Windu also incorporated Jar'Kai tactics into his own Vaapad style while on a mission on Haruun Kal, and his former apprentice, Depa Billaba, did the same.

Despite its advantages, Jar'Kai had its drawbacks. Because both hands held individual lightsabers, two-handed blows were impossible, and the duelist was unable to put all of their weight behind blocks, which weakened their defensive capabilities. As a result, an enemy with a single hilt could simply attack a Jar'Kai practitioner's defense with brute force, battering away until the dual-blade duelist's guard gave way, as demonstrated during Anakin Skywalker's duel with Asajj Ventress on Yavin 4. However, this weakness was not absolute, as some duelists possessed the physical strength to block power attacks with only one arm; Grievous, for example, was able to effectively defend against and deliver heavy power blows due to his mechanically augmented strength. Asajj Ventress eventually developed the physical strength needed to compensate for this weakness, allowing her to hold up simultaneous bladelocks with both Anakin Skywalker and Ahsoka Tano, both of whom were Form V practitioners; she had even withstood two separate bladelocks with the towering General Grievous, who was using all four of his lightsabers.
Second, dual blades were more difficult to control than a single blade due to the gyroscopic effect inherent in lightsabers. As a result, Jar'Kai required specialized training, and without it, a secondary blade was more of a hindrance than an advantage. Fortunately, dual-blade training was fairly common among most Force-using organizations, though advanced training appeared to be less common.
A third notable characteristic is that Jar'Kai practitioners were frequently overly reliant on their weapons and bladework, which stunted the development of their other abilities. The Jedi Battlemaster Raskta Lsu, for example, was an exceptional duelist, but her devotion to lightsaber combat prevented her from developing her Force abilities, forcing her to rely on both her skill with the blade(s) and the support of more Force-adept allies to compensate. Some duelists, such as Asajj Ventress, became overly reliant on having two blades to back up one another, which put them at a disadvantage if they lost one; however, this weakness could be overcome with time.
Darth Maul, while fighting the Dark Jedi Komari Vosa on Cog Hive Seven, considered Jar'Kai to be "predictable." This makes sense, given that his mentor, Darth Sidious, could wield two sabers at any time.
Because both Niman and Jar'Kai were developed before the invention of lightsabers, they were designed with metal blades in mind. Jar'Kai even had a specialized type of sword, the Jar'Kai dueling saber, designed specifically for the dual-blade style. However, because lightsabers are sword-like, the styles were easily adapted.

Traditional Niman dual-blade regiments used a short lightsaber, the Shoto, as the off-hand weapon because the smaller blade was easier to control. This appeared to be a relatively common practice among Jar'Kai duelists within the Jedi Order, with individuals such as Sora Bulq, Aayla Secura, and others doing so. The Zabrak Maris Brood took this concept a step further by wielding dual guard shotos in combat.
However, because specialized weapons were not required to use Jar'Kai, many dual-blade combatants simply wielded two standard blades in combat. In fact, weapons other than lightsabers have even been used as secondaries, including electrostaffs, as demonstrated by Shaak Ti and Obi-Wan Kenobi, swords made of lightsaber-resistant material, which Revan or Meetra Surik may have done, and even simple knives, as demonstrated by Mara Jade Skywalker. Obi-Wan Kenobi even used a lightwhip on one occasion. Furthermore, depending on the duelist's anatomy, the number of lightsabers wielded was not limited to two. The Priapulin Master Skwelli was known among the Jedi for wielding six lightsabers. General Grievous frequently wielded four, splitting his mechanical arms to create an extra set of appendages. Grievous was able to wield six sabers by using Repulsorlifts built into his legs to grasp them in his talon-like feet, though this has never been documented. The Besalisk Jedi Pong Krell also used his extra set of arms to dual-wield double-bladed lightsabers.

During his duel with Count Dooku on Geonosis, Anakin Skywalker used Jar'Kai in conjunction with his Ataru skills. While his sudden flurry of attacks briefly caught Dooku off guard, Skywalker's lack of advanced training in either Jar'Kai or Ataru allowed Dooku to break through the Jedi's weapon array, forcing Skywalker into a defensive position before destroying one of the lightsabers. Obi-Wan Kenobi, Skywalker's master, also demonstrated skill in dual-blade combat, taking up the lightsaber of the deceased Jedi Ky Narec alongside his own during his duel with Narec's fallen student, Asajj Ventress, on Rattatak. Skywalker himself used Jar'Kai in battle several more times during the Clone Wars, including during a battle with fallen Jedi Barriss Offee in the aftermath of the bombing of the Jedi Temple.
Ventress, a Jar'Kai practitioner, originally adopted the style after Narec's death, wielding his lightsaber alongside her own. However, without Narec's guidance, she spiraled down the path of the dark side, which was reflected in her bladework, which became furiously aggressive. She demonstrated her skills to Count Dooku during his visit to Rattatak, viciously killing the competitors in The Cauldron in a furious display of bladework and raw Force power. During her subsequent duel with the Count, she attacked him in a blind rage, but was ultimately defeated. However, her skills impressed the Count and his Sith Master, Darth Sidious. The Count awarded her a high-ranking position in the CIS military, as well as the twin curved lightsabers of his former student, Komari Vosa. Ventress developed her skills under Dooku's tutelage, applying her dual-blade combat skills to Makashi, while wielding these new lightsabers. Eventually, her dueling prowess allowed her to easily hold her own against up to three opponents, as she demonstrated during her mission to Ruul.

Her skills even progressed to the point where she could fight and defeat or at least hold her own against Jedi Council masters, which few of her contemporaries could do. However, despite her abilities, she had flaws. She lacked the physical strength needed to compensate for Jar'Kai's inherent weaknesses in her early years; her blows lacked power, as evidenced by Dooku's casual defensive moves during their fight on Rattatak; and she was vulnerable to power attacks, as evidenced by her retreat from Anakin Skywalker's offensive frenzy during their duel on Yavin IV. However, she eventually developed the physical strength needed to compensate for this weakness, demonstrating the ability to hold up simultaneous bladelocks with both Anakin Skywalker and his Padawan, Ahsoka Tano, both of whom were Form V practitioners.
Darth Maul is also known to have trained in Jar'Kai and mastered it to the point where even Darth Plagueis recognized his skill in dual-blade combat. However, Maul rarely used Jar'Kai, preferring to wield a saberstaff instead, as demonstrated during his duels with Jedi Master Qui-Gon Jinn on Tatooine and Naboo. During much of the Clone Wars, he also appeared to prefer a single-blade approach to dual-wielding, as seen in his duels with Obi-Wan Kenobi. However, he was able to defend against and defeat Komari Vosa, even though she had a two-to-one saber advantage over him. Maul took up both his own saber and the Darksaber in his final duel on Mandalore with Darth Sidious. Despite his infrequent use of Jar'Kai, his skill in the style had clearly improved significantly, allowing him to fight almost evenly with his former master, who also used dual blades, though he was ultimately overpowered. When the reborn Maul dueled Darth Vader on Kalakar Six, he used Jar'Kai after his saberstaff had been sliced in half, allowing him to unleash his full potential and bring Vader to his knees.
Luke Skywalker initially used dual blades to combat Lumiya's lightwhip, as the weapon's multiple extensions easily defeated standard defensive techniques. In their rematch, Skywalker used his newly created shoto to support his full-length lightsaber, entangling the energy beams of her whip with one blade while cutting apart the physical strands. Skywalker disarmed Lumiya by shorting out the energy beam of her whip with a power attack, though he lost his lightsaber in the process, before attacking her with the shoto. Dual-blade combat became one of Skywalker's preferred methods for dealing with lightwhips, and he used it several times during various rematches with Lumiya, though he only used a single weapon in their final encounter. He also encouraged his wife, Mara Jade Skywalker, to build her own shoto for the same reasons. Skywalker also demonstrated his dual-blade skills while training his students.

While many duelists have used Jar'Kai at some point, fewer have done so on a regular basis. Awdrysta Pina, who practiced with a pair of Jedi katanas, Kavar, Bastila Shan, Vandar Tokare, and Fortris Gall are among the ancient Jedi who did so.
During the Jedi Civil War, many of the Dark Jedi who pledged allegiance to Darths Revan and Malak's Sith Empire used Jar'Kai against their former Jedi brethren. Many of the Sith who followed Darth Traya's Sith Triumvirate used the Jar'Kai form in combat.
During the New Sith Wars, the Sith Lord known as the Dark Underlord practiced Jar'Kai, wielding two Sith swords. During this time, the style also had its share of Jedi practitioners, including the Echani Jedi Master Raskta Lsu and the Twi'lek Jedi Newar Forrth. The Twi'lek Dark Jedi Boc Aseca attempted to imitate Forrth more than a millennium later, resulting in a clumsy but effective fighting style.
During the Clone Wars, General Grievous incorporated Jar'Kai elements into his combat style. He frequently used two lightsabers in battle, but he also demonstrated the ability to wield four by splitting his mechanical arms and hands lengthwise, resulting in four arms. Grievous's contemporaries, Asajj Ventress, Sora Bulq, and Saato, also used Jar'Kai in combat. Bulq, a master of all known forms of lightsaber combat, frequently wielded a shoto as his secondary weapon in combat, applying his Jar'Kai skills to his Vaapad practice, the legendary Form VII variant that he had helped Mace Windu develop prior to his defection to the CIS. Keelyvine Reus and Pong Krell were two other Jar'Kai practitioners active during the Clone Wars. Darth Sidious was also extremely skilled in Niman/Jar'Kai, using both his primary and backup lightsabers to fight his former Sith apprentice Darth Maul and Savage Opress, though he rarely used it. His skill, however, allowed him to overcome their combined abilities and overpower Maul shortly after his brother's death.

Ahsoka Tano was also proficient in Jar'Kai and wielded both a lightsaber and a shoto. She used an extremely complex Ataru-Shien reverse grip style in her Jar'Kai tactic, which was worthy of mastery. She was able to hold her own against both Anakin Skywalker and Obi-Wan Kenobi on Mortis and pose a challenge to Grievous, who was a master of Jar'Kai and was using four lightsabers at the time. Tano lasted significantly longer against Grievous than she had in their previous duel on Skytop Station, which occurred before she began using two lightsabers. Tano later lost her shoto and it was revealed that she had become somewhat vulnerable to the weakness of becoming overly reliant on it, a trait she shared with Asajj Ventress, and she was unable to defeat the treacherous Barriss Offee in combat when using a single lightsaber.
Count Dooku, a renowned Makashi practitioner, considered dual-blade combat styles to be inferior, believing that duelists should either make do with a single blade or not at all. He even blamed double-bladed lightsabers for this.
During the Dark Times, Maris Brood, a Zabrak Jedi Padawan who used two guard shotos in combat against Darth Vader's secret apprentice, Galen Marek, was a notable Jar'Kai practitioner. Many of Marek's unstable clones—including the two more successful clones, Starkiller and the Dark Apprentice—adopted the form during their training under Vader, using it during their emergence. Starkiller studied Ataru and Niman to take advantage of their dual-blade training regimes and facilitate his mastery of Jar'Kai, and he also frequently chained Force-based attacks into his bladework as part of Niman. Jeng Droga and Sa Cuis, two of Darth Sidious's Dark Jedi, favored dual blades.

Fourteen years after the destruction of the second Death Star, many of the New Reborn were trained in the Jar'Kai style, most notably Axmis' apprentice, Alora. Many Jedi also used Jar'Kai to fight Axmis' Reborn.
A'Sharad Hett, a Jedi Knight from the Clone Wars era, was a well-known dual-blade fighter who used his late father's weapon alongside his own. After falling to the dark side and becoming the Sith Lord Darth Krayt, he continued to practice Jar'Kai in conjunction with his knowledge of Form VI lightsaber combat. Various members of Krayt's Sith Order also practiced Jar'Kai, including the third Darth Wyyrlok and Darth Reave.
Micah Giiett, Joclad Danva, and Serra Keto were among the other Jar'Kai practitioners.
Some duelists maintain their dual-blade combat skills and use them frequently, but not consistently.
Kas'im, a Sith Lord and Sith Blademaster, demonstrated his dual-blade combat skills against Darth Bane in the final year of the New Sith Wars, before the events of the Seventh Battle of Ruusan, using the Ataru subform. Kas'im, who had mastered all seven classic forms and typically used a double-bladed lightsaber, always discouraged his students at the Korriban Sith Academy from using Jar'Kai, claiming that it was inherently flawed. However, Kas'im's Jar'Kai expertise was such that he was able to confuse Bane and nearly defeat him.

Known Jedi duelists who sometimes employed Jar'Kai include Aayla Secura. During the Clone Wars' most intense battles, she often used a shoto alongside her lightsaber, though she could effectively use a standard blade as her off-hand weapon.
Luke Skywalker, Grand Master of the New Jedi Order, demonstrated his proficiency with this dual-blade technique during the Yuuzhan Vong War, frequently combining a shoto with his regular lightsaber. Approximately five years following the Swarm War's conclusion, Skywalker engaged in actual Jar'Kai combat with the Dark Lady Lumiya on Roqoo Depot and at Gilatter VIII during the Second Galactic Civil War. When Lumiya resurfaced, Luke Skywalker requested his wife Mara Jade to construct a shoto. She accompanied Luke on Roqoo Depot during his fight with Lumiya, and simultaneously, she battled Dark Jedi Alema Rar. Mara Jade also utilized a Jar'Kai variation during her duel against her nephew and Lumiya's Sith apprentice, Jacen Solo, on Kavan, employing both her shoto and vibroblade.
Sith Master Lomi Plo employed Jar'Kai against Skywalker in two of their three duels, using a standard lightsaber and a shoto.

During the Battle of Korriban in the Great Galactic War, Jedi Master Kao Cen Darach wielded his own single-bladed lightsaber alongside his apprentice's double-bladed one against Vindican and his apprentice, Malgus. While Darach managed to injure Vindican, Malgus mirrored the Jedi's action, seizing his own master's lightsaber and using the additional blade to overcome Darach's diverse weaponry, ultimately defeating him.
To equalize the battle against General Grievous' numerous weapons, Kit Fisto picked up the lightsaber of his former Padawan, Nahdar Vebb, during their duel. With this second lightsaber, he unleashed his Jar'Kai skills, combining them with his mastery of Form I lightsaber combat, pushing back Grievous and holding his own against three of the General's IG-100 MagnaGuards.
Beyond his application of this fighting style against Dooku on Geonosis, Anakin Skywalker executed Jar'Kai against Duros bounty hunter Cad Bane, using his own lightsaber and his Padawan Ahsoka Tano's in the Devaron system. He also used Luminara Unduli's lightsaber in the Progate Temple on Geonosis before freeing her from Queen Karina the Great and giving it back. Furthermore, he engaged in Jar'Kai against former Knight Barriss Offee.

During the Summertime War on Haruun Kal, both Mace Windu and his former student, Depa Billaba, occasionally utilized their mastery of Form VII lightsaber combat with two blades. Shaak Ti also seemed to possess some training in this style, skillfully wielding an electrostaff alongside her lightsaber during the Battle of Coruscant. Sources indicate she wielded dual lightsabers following the Jedi Purge.
Barriss Offee, formerly a Jedi, showcased considerable skill in Jar'Kai after taking Asajj Ventress' lightsabers. Her proficiency was sufficient to overwhelm Ahsoka Tano and put up a strong fight against Anakin Skywalker.
It is understood that many, if not all, duelists have at some point applied Jar'Kai in battle, even without specialized knowledge, typically when the situation warranted or allowed it. Known duelists include Exar Kun, Aurra Sing, Lycan, Quinlan Vos, Corran Horn, Anakin Solo, Saba Sebatyne, Vestara Khai, and Kol Skywalker.
George Lucas initially envisioned lightsabers as exceptionally heavy and unwieldy, making dual-blade combat seem impossible. However, he later decided to lighten lightsabers to facilitate faster choreography in Star Wars: Episode V The Empire Strikes Back, implicitly opening the door for dual-blade fencing. Dual-blade combat first appeared in Star Wars (1977) 96, where Luke Skywalker fought with a short lightsaber as an off-hand weapon to counter Lumiya's lightwhip.
William C. Dietz and Dave Dorman's novella, Dark Forces: Jedi Knight, suggests that dual-blade combat predates the invention of the lightsaber. Furthermore, in the Star Wars computer game Star Wars: X-Wing Alliance, there exists a pair of "Jar'Kai dueling sabers" that are simply ordinary metal swords. This also implies that Jar'Kai existed before lightsabers, even though X-Wing Alliance was released before the behind-the-scenes "invention" of lightsaber forms. A Wizard of the Coast supplement confirmed this, revealing that the Jar'Kai style and swords originated with the Yovshin Swordsmen of Atrisia.

Originally, Dooku was intended to showcase his skill with two blades against Jedi Master Yoda in Star Wars: Episode II Attack of the Clones, potentially making him a Jar'Kai practitioner. However, this idea was later abandoned, and in the novel Labyrinth of Evil, Dooku was described as disliking the use of multiple blades, making him an unlikely Jar'Kai practitioner. Promotional pictures featured Christopher Lee wielding two lightsabers with visual effects; one such image appears in the Star Wars: Attack of the Clones: The Visual Dictionary. Additionally, the comic version of Attack of the Clones included the scene of Dooku wielding two lightsabers.
In the video game Star Wars: Knights of the Old Republic, a character's proficiency in the Jar'Kai form was determined by a set of three feats called Two-Weapon Fighting. Acquiring these feats enhanced the character's skill in dual sword or lightsaber combat, while also improving their ability to wield double-bladed lightsabers and swords, and even dual blasters. However, in the game's sequel, Star Wars: Knights of the Old Republic II: The Sith Lords, the Enhancement D-Package implant allowed a character to effectively use two weapons without needing to acquire the Two-Weapon Fighting feats. Furthermore, Sith Marauders and Jedi Weapon Masters could learn the "Superior Two-Weapon Fighting" feats, granting unparalleled mastery of two-weapon combat.
Similarly, in the Star Wars Roleplaying Game: Saga Edition, characters can acquire Dual Weapon Mastery feats that serve the same purpose. Curiously, none of these feats are required to take the Jar'Kai talent of the Jedi Knight prestige class, although Niman is a prerequisite.