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"They're not people; they're machines! Replicators!"
Rodney McKay[src]

The Asurans are technological nanomorph life-forms from Asuras, a planet located in Pegasus, a satellite galaxy of the Milky Way. Originally created by the Lanteans as a means of fighting the Wraith and were referred to as Replicators by the Asgard, and the Tau'ri.



"When the Ancients concluded that the experiment had gone too far -- that we would never become the weapon they desired to create -- they decided to end it."

The Lanteans' attack on Asuras.

During the war with the Wraith, the Lanteans sought to create a weapon which would attack Wraith DNA. Turning to nanite technology, the Lanteans built nanites which would allow for organic assimilation and self replication, encoded with an aggression code that surpassed even that of the Wraith. Without warning, the nanites suddenly began replicating and interlocking, taking the most advanced form they knew—human. Even in this form, the aggression codes remained. Fueled by a rage they could not understand, the machines begged the Lanteans to remove the aggression programming, but the Lanteans refused, for they had created base codes that prevented the Asurans from harming them, and they were desperate to find a weapon to destroy the Wraith.

When they concluded that the Asurans would not be the weapon they sought, the Lantean Council sent a fleet of Aurora-class battleships to Asuras, wiping out the laboratory and the nanites, and deleted all references to the project from their database, save for Asuras' Stargate address. However, some of the nanites survived, and began to replicate again which resulted in the Second Birth.

After the Lanteans lost the war and returned to the Milky Way galaxy, the Asurans, having regained most of their former strength, reemerged in the Pegasus Galaxy and launched their own offensive against the Wraith. In their arrogance, the Wraith believed that they could once again utilize their superior numbers to achieve victory as they had against the Lanteans and attempted to do so but as the conflict ground on, grim realism began to set in as the Wraith command realized the Asuran offensive became practically unstoppable; not only did they possess a technological advantage, the Asurans were also immune to Wraith feeding due to the fact that they were robots, were physically superior beings and most importantly, they could more than match the quantity of Wraith production of warships and troops. At the climax of the conflict, Wraith Hive Ships were, in mere weeks at a time, falling by the hundreds and Cruisers by the thousands while the Asurans were completely unfazed by the loss of any amount of their ships, able to simply replace them in a very short time.

The Wraith, after suffering this seemingly-endless series of shattering defeats, finally concluded that they could not hope to militarily compete with the Asurans and subsequently created a shut down code that deactivated the Replicators' directive to attack them. This resulted in them returning to their homeworld where they isolated themselves to that planet alone. (SGA: "Progeny", "Reunion")

Children of the Ancients

"We’re not taking you to Atlantis. Our intention is to destroy it."

The Atlantis Expedition meet the Asuran Council and its leader, Oberoth.

Ten thousand years later, the Asurans had achieved much: they had built many City-ships as well as surrounding structures, and were able to mass-produce Zero Point Modules as fast as the Lanteans could. Most of the Asurans, such as Oberoth, were content to live as they had, but some, like Niam, desired to ascend and truly equal their creators. When the Atlantis expedition contacted them, the Asurans welcomed them at first, claiming that they were a faction who had split with the Lanteans over how to act in the war with the Wraith. Upon learning that their visitors needed ZPMs, they forcefully probed their minds and learned that their visitors, many of whom were descendants of the Lanteans, had taken up residence in a very much intact Atlantis. Intending to destroy Atlantis out of retribution, they sent one City-ship to Lantea; however, Dr. Rodney McKay, with the help of Niam, tried to alter their Base code and remove their aggressive tendencies. McKay also created a program that froze the Asurans, and rigged the City-ship to detonate. Taking Niam with them, the team escaped via Puddle Jumper after the explosion. All was well until the other Asurans reset Niam's programming and he attacked Dr. Elizabeth Weir, but he was ejected into space and eventually went dormant in orbit. (SGA: "Progeny")

Later, after Atlantis had been reclaimed by living Lanteans, the Asurans attacked the city. Having found a way to overcome the code which prevented them from harming their creators, they killed the Lanteans, occupied the city and took Major General Jack O'Neill and Richard Woolsey captive. Lt. Colonel John Sheppard, Weir, McKay, Ronon Dex, Dr. Carson Beckett, and Teyla Emmagan hatched a daring plot to rescue O'Neill, Woolsey, and Atlantis. They initially attempted to use Niam to upload a virus into the Asurans which would freeze them for seven hours, allowing them to attack the Asurans. However, Niam reactivated, forcing them to kill him. As a new plan, they modified the city's shield emitters to release a massive Replicator disruptor wave, destroying the Asurans who invaded the city. (SGA: "The Return, Part 1", "The Return, Part 2")

Angered that both attempts to take the city failed, they started to build a fleet of ships to strike at the heart of the problem – Earth. The Apollo made short work of this plan by destroying the at least seventeen ships with the Horizon weapon. The Asurans then attempted to destroy Atlantis a third time with a Stargate Satellite, firing a sustained energy beam through the Stargate at Atlantis. All attempts to destroy the satellite failed. Using their unlimited ZPMs, they were able to keep the Stargate open indefinitely. The Asurans almost succeeded in destroying Atlantis, only to have it fly away. (SGA: "First Strike")

The Enemy of My Enemy

"We overload their ZPMs – about half a dozen of them in a symmetrical pattern around the Replicator mass. The force of the explosion causes the mass to compress even further, essentially creating our own Replicator fusion bomb. The whole planet's gonna be destroyed in the process."
Rodney McKay[src]

The Asurans remained on their homeworld for a time until their base was infiltrated by the Atlantis expedition's flagship team, Atlantis Reconnaissance 1.

After stealing a Zero Point Module from the Asurans, Dr. Rodney McKay activated the Asuran command directive that forced the race to attack the Wraith. It was discovered that the directive had been deactivated for centuries by the Wraith through the use of a computer virus. The directive was reactivated by the team, but Dr. Elizabeth Weir was captured by the Asurans. Lt. Colonel John Sheppard, McKay and Ronon Dex attempted to escape in a Puddle Jumper, but got cornered by an Asuran cruiser. They were saved by the timely arrival of the Apollo which laid down covering fire for them to land in one of the ship's 302 Bays and then jumped to hyperspace without taking any damage. (SGA: "Lifeline")

Wraith battle the Asurans.

After being activated, a fleet of Asuran cruisers departed Asuras and attacked a Wraith planet. The Asuran-Tau'ri-Wraith war had begun, which at first, caught the Wraith off guard and allowed the Asurans to take a quick and decisive lead over the Wraith in the conflict. However, the Wraith began to resist more fiercely which saw the destruction of two Asuran cruisers early in the war. Despite a convincing string of successes against the Wraith in battle, the Asurans concluded that their progress was insufficient and, through careful study, recognized a weakness within the Wraith: dependence on humans as a food source. As such, the Asurans developed a new tactic: wiping out human settlements in order to starve the Wraith. (SGA: "Tabula Rasa", "The Seer")

Six human worlds were destroyed in the Asurans' new plan; however the Asurans did not abandon their original strategy of engaging the Wraith in battle and as a result, the Atlantis Expedition calculated that at least a dozen Hive ships were destroyed as well. (SGA: "Inquisition")

The allied fleet prevails in the Battle of Asuras.

After the Atlantis expedition developed the means to track the Asuran Aurora-class battleships deployed throughout the galaxy, they decided to put the Asurans on the defensive. Attacks by the Apollo and the Daedalus using new Asgard weapons forced them to retreat to their homeworld, congregating all of their ships at Asuras for safety in numbers. Thanks to a new plan developed by McKay, an alliance was formed between the Atlantis expedition, the Wraith, the Travelers and FRAN, a Replicator McKay created. The Daedalus, the Apollo, seven Wraith Hive ships and seven Travelers ships, including their Aurora-class battleship, launched an all-out assault on Asuras to turn all of the Replicators into a mass of nanites and overload their Zero Point Modules, destroying the planet in the process, taking the Asurans with it.

Thanks to FRAN sacrificing herself as part of the plan, and some improvising by McKay and Colonel Samantha Carter, the Asurans turned into a dense mass as planned and sank to the planet's core causing it to implode, destroying Asuras and the Asurans. Later, it was revealed that at least some survived off-world, as an Asuran ship commanded by Dr. Elizabeth Weir arrived to investigate the planet's destruction. It was indicated that they were not allies of the destroyed Asurans. (SGA: "Be All My Sins Remember'd")

Quest for Ascension

Asurans meditating in hope of Ascension

A group of Asurans developed an artificial means of attaining Ascension after numerous failures. They lost their physical nanite bodies and existed as beings of energy embedded in subspace in order to be one step closer to true Ascension. However, there was no higher level as they had been reduced to bodiless beings of energy that traveled the galaxy in order to find new physical bodies. They encountered and inhabited both Wraith technology and other advanced races which were hiding from the Wraith, but neither were sufficient for the task. As time grew on, this faction of Asurans were growing more and more bitter.

However, Dr. Elizabeth Weir - who was the leader of this group - attempted to locate Atlantis and use its technology to help the group regain physical bodies. She inhabited a Puddle Jumper piloted by Lt. Colonel John Sheppard and his team allowing her mind to return to and inhabit Atlantis. This allowed her to use the Nanite creation machine to construct a Replicator body that appeared as FRAN, and her eight other Asuran comrades then entered the city, wishing to regain physical bodies as well. When denied, they attempted to sink the city but relented when they feared the Nanite creation machine would be destroyed in such a move. Negotiations were made by Weir who convinced the Atlantis expedition to allow them to regain their bodies in order to create organic based bodies. However, Koracen betrayed the group and used a time delay program to create a power outage allowing him to escape. He was ultimately killed by Weir who decided that even seven Asurans were a danger.

Weir took her Asuran followers through the Stargate to enter a world where they could continue to make organic based bodies. However, this was a trick orchestrated by the Atlantis expedition who gated the group to a Spacegate, causing them to freeze and become immobile in the cold vacuum of space. This marked the death of all Asurans in the Pegasus galaxy. (SGA: "Ghost in the Machine")

With the help of an Ascended Asgard named Ran, Weir was Ascended for real and spent a time amongst the Ascended of the Pegasus Galaxy. However, after she intervened to save McKay's life, she was returned, amnesic to human form. Her transformation into an Asuran was reversed and she was once again human. After helping deal with the Vanir problem, she rejoined the Tau'ri. (SGA: "The Third Path")


The basic appearance of an Asuran as it changes its form.

"In these tiny killing machines, the Lanteans imbued an aggression that surpassed even that of their enemy. The technology allowed for organic assimilation and self-replication to increase their effectiveness ... and replicate they did."

The Asurans, though appearing as humans, were actually constructed of millions of nanites, giving them abilities such as shape-shifting, increased strength in human form, and the ability to scatter inside a human to attack or interface with them on the microscopic level.

Digital Ascension

The digital ascension process.

Digital ascension was a process, created by Koracen, in which a Replicator can ascend to a layer of subspace, much like an organic being ascends to a higher plane of existence. In this process, a replicator's consciousnesses is enabled to exist indefinitely as a field of energy. As such a being, they can essentially upload their minds to subspace and let their Nanite body disintegrate, allowing them to move freely about the galaxy at will. However, the Replicators who accomplished this grew dissatisfied with this existence, as they could not actually ascend to the higher planes, only subspace. Because of this, they regained physical form by creating new bodies in Atlantis. (SGA: "Ghost in the Machine")

Nanite construction

"Aggressive little bastards."
John Sheppard.[src]

Asuran nanites.

The Asurans, while appearing to be a human, are actually a collection of microscopic nanites that combined to form a much more complex organism that mimics the form of their creators; the Lanteans. As such, while they might appear to be Human, they are in fact a machine based species with a great level of strength which can easily overpower a Human. (SGA: "Progeny")

They were capable of being created on the surface of the nanite creation machine where the nanites coalesced into a silvery human shape whereupon an organic appearance took form. (SGA: "Ghost in the Machine")

Furthermore, their lack of a true skin meant that projectile weapons were useless against them as the bullets simply passed through their bodies. Any "wounds" simply healed at an accelerated rate with no degradation in the Asuran's movements. Certain forms of energy weapons seemed to be capable of stunning them but only for a moment. (SGA: "Progeny")

All Asurans were far stronger than humans and were capable of sending a human flying with just a single push. (SGA: "Ghost in the Machine")

Asuran probing a Human mind.

In addition to this, the nanites in their body allowed them to probe the minds of Humanoids in a similar capacity as that of the Milky Way's Human-form Replicators. All that was required was for the Asuran to move their hands to the forehead of the individual and press forward. The nanites passed through the skin where it interacted with the brain of the organic being. In this state, the Asuran was capable of replicating a virtual world with the Human being unaware of the probing. This process allowed the Asuran to experience the memories and thoughts of the Human though those with prior experience of this action can resist their attempts. When exiting the probe, the Human typically experiences a great deal of pain. This process was described by Richard Woolsey as the most painful experience he had ever seen. Despite this, it appears that the process could be made painless, as Niam did by sharing visions with the cooperative Dr. Elizabeth Weir. Other Asurans were capable of doing this act on their own kind. They were also capable of killing fellow Asurans by placing their hands in the body of another Replicator and severing the nanite bonds causing them to disintegrate into a pile of dust. (SGA: "Progeny", "The Return, Part 2", "Lifeline", "Ghost in the Machine")

Nanites reconstituting on the other side of the door after passing through minuscule cracks.

Obstacles that were in the way of the Asuran were also not a problem to them as their nanites were capable of slipping through the minuscule cracks within door mechanisms whereupon they reconstitute themselves on the other side. This meant that physical obstructions did not impede their movements. (SGA: "Progeny")

One insidious ability of the nanites was their capacity to infect other races by a simple touch. A single brief moment of contact can allow an Asuran to infect a person with the nanites which begin replicating immediately inside the body. As they begin multiplying exponentially, they start to slowly consume the body of the host. The host body remains in a coma-state while this occurs and while the nanites were quite capable of killing it, in their diminished numbers they would not be able to survive on their own. This was why they began stripping the body of raw material to produce more of their number thus transforming the host into a new Asuran.

This was only done so until they reached sufficient numbers to begin their own independent entity. This was one method through which they were capable of creating more Asurans but was not considered the standard practice and was more like a last desperate attempt to survive by the infecting Asuran. In this state, the nanites were vulnerable to electromagnetic pulses though they were capable of consuming the organic tissue of a body and integrate it into their form thus making them immune. As part of their programming, the nanites immediately find and destroy any form of Wraith DNA within the host body in an aggressive fashion.

Nanites infecting a Human body, the red spots highlighting their spread.

The nanites contain an element of the infecting Asuran's personality which attempts to subvert the mind of the Human host through trickery. The power of the Replicator personality was determined by how many nanites were within the host body and the mind worked to suppress the immune system of the host in order to give the nanites the freedom to reproduce their numbers. This was why the host was in a coma state and was completely unaware of the process. (SGA: "The Real World")

The Asuran nanites were highly aggressive due to the nature of their programming as they were to be used as a bioweapon. This was so great that it surpassed their enemies even. The technology used allowed for the organic assimilation and self-replication to increase their effectiveness. This increased to the point that the molecular machines began to form even more complex organisms and eventually evolved into the most efficient form they knew of which was that of their creators. The nanites were able to incorporate organic material into their makeup if the raw material was available. (SGA: "Progeny", "The Real World")

The unique nature of the nanites meant that Neutronium was a vital component in their manufacture. In their unaltered state and in small numbers, the nanites were also vulnerable to electromagnetic pulses which was capable of destroying the small machines. They were also incapable of surviving unaided in the void of space. Direct solar radiation severely diminishes their power levels leaving them incapacitated, but not dead. (SGA: "Hot Zone", "The Real World", "The Return, Part 2", "Be All My Sins Remember'd")

Asuran nanites were capable of creating Organic Asurans atom by atom making a living breathing being. (SGA: "This Mortal Coil", "Ghost in the Machine")


An Asuran, shot by an ARG.

"They're energy weapons. They disrupt the link between the nanites' cells. The Replicators literally fall apart when you fire on them."
―Rodney McKay[src]

Due to the nature of their construction, the Asurans have proven to be very difficult to terminate with weapon fire only stunning them temporarily. However, due to their relationship to the Human-form Replicators that invaded the Milky Way galaxy a few years ago, it was quickly discovered that the use of a disruptor weapon, also known as an Anti-Replicator gun, was capable of disrupting the link that allowed the nanites to form a Human shape. This essentially destroyed the Asuran in the process which would crumble into a pile of dust-like particles. (SGA: "Progeny", "The Return, Part 1", "The Return, Part 2")

However, the Asurans have proven to be very adaptive to weapons that can harm them and repeated uses of ARG weaponry helps the machine race to develop an immunity to the device. This combined with the ability of the Asurans to recreate destroyed members of their race demonstrates how difficult it is to actually destroy the machine race. (SGA: "The Return, Part 2", "First Strike", "Lifeline")

A group of Asurans exposed to space.

Another means of termination is to expose an individual Asuran to outer space. The individual doesn't crumble into a pile of dust, but can be frozen, as the solar radiation has the ability to freeze the bonds between nanites, incapacitating them. But they can be reactivated by anyone capable of space travel. (SGA: "Progeny", "Ghost in the Machine")

Asurans are able to kill one another, by placing their hands through the foreheads of a counterpart Asuran, after which they are able to sever the bonds of the nanites holding the body together, thus killing them as they turn into a pile of dust. (SGA: "Ghost in the Machine")

Programming and subspace link

The Base Code.

"The Ancients put in place measures to prevent us from altering the code ourselves ..."

Being a machine race, the Asurans are ultimately governed by the coding with which the Lanteans programmed them. As they were designed to be a weapon, the Asurans were created to be highly aggressive which was at the core of their being. This fuelled a rage that they were incapable of containing and even surpassed that of the Wraith. The nanites themselves had this programming present within them, which forced them to actively find and destroy Wraith tissue in the body. (SGA: "Progeny", "The Real World")

The Lanteans implanted a number of directives within the Asurans' Base code. This was incredibly complex and contained a code of over three billion chemical base sequences. It included parameters that prevented the Asurans from harming their creators and from tampering with the code themselves. Another directive prevented them from altering their physical appearance to match another living being. The basic core of their being was programmed in a way that made them feel a need to attack the Wraith. While this was the case, it was possible for outsiders to alter the Base code. Initial tampering allowed for the Asurans to alter their own programming, allowing them to bypass the directive that prevented them from harming their own creators. (SGA: "Progeny", "The Return, Part 1", "The Return, Part 2", "Lifeline", "This Mortal Coil")

Subspace link.

The Asurans were each individual units despite their basic command code being interconnected over a powerful subspace frequency. While this was the case, they were not a collective hive mind like the Milky Way Replicators. This expansive subspace network linked them all together and allowed them to know whatever their comrades were perceiving. This also allowed them to watch for signs of betrayal among their kind and were capable of resetting a rogue Asuran who has reverted to their base programming which is a highly aggressive state that attacks any enemies that it perceives. While rogue Asurans were capable of being reprogrammed by the collective, certain groups were capable of maintaining their presence and hiding within it. The subspace collective allowed the Asurans to track their own movements. (SGA: "Progeny", "Lifeline", "This Mortal Coil")

Perception through the subspace link.

A key advantage provided by the subspace link was the capacity to adapt to certain threats. This was namely the case against the threat posed by Anti-Replicator guns. While ordinarily the weapon was able to break the bonds between the nanites, continuous exposure to the energy allows the Asurans to collectively work out it's frequency and develop an immunity. Furthermore, it allowed them to restore a deceased member of their kind allowing for a destroyed Asuran to be recreated. Each of the Asurans exist within the collective and can be replicated many times. This was done through the subspace collective which was responsible for digitizing the Asuran mind and aiding in its placement within a new body. (SGA: "The Return, Part 1", "The Return, Part 2", "First Strike", "Lifeline", "Ghost in the Machine")

A further addition to the subspace network was a periodic collective update known as Merges. This allowed the Asurans to exchange new information among themselves and disseminate new data among their people. Any hacking into their network can be detected once a Merge occurs which causes all the Asurans to freeze until all the new data has been distributed among their kind. While they were capable of doing this normally, the Asurans also possessed a Central data core which acts as a backup hard drive for the collective and aids in spreading the data of a Merge. (SGA: "Progeny", "Lifeline")

The Asuran Central Data Core serves as a backup hard drive.

While a potent advantage, the subspace link and their programming has shown a number of weaknesses. Outsiders were capable of altering the base code and were capable of causing a momentary freeze that affected all the Asurans. The Wraith demonstrated the capacity of infecting the Asuran's with a virus that deactivated their directive that forced them to attack their mortal enemies. Attempts to manipulate the link can be established by a small number of nanites or by captured lone Asurans. However, despite this being the case, the Asurans demonstrated the ability to harden their defenses to prevent such attacks in the future. (SGA: "Progeny", "The Return, Part 2", "Lifeline", "Reunion", "The Seer")



"They are our creators, and ascension is the final step to equaling them, to becoming one with them."

Very little has been seen of actual Asuran society, though it appears to mimic that of the Lanteans in design. However, as a civilization, its been noted that the species actually changed little since their original construction. Most Asurans decided to continue this way of living, though some wished to break the static society they live in. (SGA: "Progeny")

Niam and the group seeking Ascension.

Some Asurans - such as Niam - sought to fight their aggressive instincts and remove it in order to achieve Ascension like their creators. Despite the feeling of betrayal their kind feel toward their makers, they simply wish to emulate their creators to the fullest extent and become one with them. This group was considered renegades by the greater Asuran society, who did not hesitate to exterminate their kind. (SGA: "Progeny", "This Mortal Coil")

Most of the Asuran species believe that they were betrayed by their creators and abandoned for the favored siblings; Humans. As such, the Asurans tend to lash out against Humans and seek to wipe out the last traces of the Lanteans. They view the Tau'ri with great envy and hatred due to the fact that many are direct descendants of the Lanteans, they are from Earth, the homeworld of the Lanteans, and they now inhabit Atlantis, the city of the Lanteans. They viewed organic-based life as being indifferent to their own and saw humans as simply another form of machine. (SGA: "Progeny", "The Return, Part 1")

It was thought by some of the Asurans of this "heretical" belief system that they should not abandon their technological origins and sought an artificial means of ascension. (SGA: "Ghost in the Machine")


Main article: Asuran technology

The Asurans had numerous advanced technologies at their disposal. More or less, however, they imitated the outdated Lantean technology in use until they were abandoned and almost destroyed by their creators, most notably City-ships and the Aurora-class battleship, because they desired to equal their creators, and it was also the most advanced technology known to them. Until Dr. Elizabeth Weir joined them, there is no evidence of them ever researching their own technology, and as the Milky Way Replicators were unable to develop their own technology, it is unlikely they could either. For this reason, most of the technology used by the Asurans is inferior to the technology used by the Lanteans just before they returned to Earth, such as their Drone weapons and Shields.


Main article: Asuran fleet

As an imitation of the outdated Lantean fleet, the Asuran fleet was primarily composed of Aurora-class battleships and cruisers.

Known Asurans

Stargate Wiki has a collection of images related to Asuran.

Worlds under Asuran control


  • It's possible the origin of their name comes from the Hindu "Asura", a demon/wraith of sorts.

See also

External links