The Replicators are very sophisticated machines that, driven by the instinct to reproduce and to feed on the very technology that might defeat them, have wreaked havoc in several galaxies.
The Replicators that originated in the Milky Way exist in two forms. The first appears as a mechanical analog of an arachnid or spider. Individuals of this form have simple but highly destructive behaviors and the capacity for independent action at a basic, instinctive level. Their success in overcoming advanced beings and technology is a result of their ability to reproduce, to learn, and to act collectively to achieve a common aim. Over a sub-space communication network, the computing powers of the individuals are used together to create and transmit new instructions for all Replicators, advancing their mission. In this way they are even able to take command of on-board ship's systems such as navigation or sensors. By applying what they have learned collectively in the past, they are even able to modify such systems. They always seek more advanced technology than what they currently have.
Each mechanical Replicator is made of "blocks" held together by a keron-based energy field. A keron is an energy particle unknown to Earth scientists. Each block has advanced computing technology, although a single block by itself is inert.
Replicators ingest raw materials, such as ship hulls, which they use to construct additional Replicators. To help with ingestion, they spray acid at the materials from a mouth-like spout. The acid spray may also be used as a weapon. Replicators are able to use a ship's power to help in the replication process; thus they seek out energy sources. A critical mass of blocks is necessary to link up via the keron energy and form a new Replicator. A larger number of Replicators achieves a higher level of cognition, provided the sub-space network is functioning.
The second, more evolved Replicator has a human form; it is capable of very advanced reasoning and independent action. Still, lIke their mechanical predecessors, human form replicators are greatly strengthened by their collective computing, or reasoning. Human Form Replicators tend to establish a hierarchy of command amongst themselves. They are able to communicate with and control mechanical replicators en masse. Human Form Replicators are comprised of nano-scale components as well, only with no visible blocks. In fact they are able to morph their appendages very precisely through a liquid state into a new solid shape, then back to human form again. They are able to command structures built of their own components, from walls to entire ships, without physical contact.
Human Form Replicators are able to enter the minds of biological beings such as humans. While doing so, they may create false realities for the human in order to elicit information or some desired behavior from them. The humans experience pain from the ordeal, but no lasting effects.
Replicators cannot be damaged by typical energy weapons. The mechanical form can be disabled by blasting the blocks apart with projectiles such as large-caliber bullets. This does not work on the Human Form Replicators, whose nanite-sized components must be disrupted at a nearly atomic level.
The Replicators were defeated in the Milky Way and in the Asgard galaxies by adapted Ancient weapons technology. However, a being similar to the Human Form Replicator is active in the Pegasus galaxy. These beings are called Asurans and may be related to the Replicators by a common Ancient creator.
Earth first learned of mechanical replicators when some of them infested and piloted Thor's ship Beliskner into Earth orbit. Each Replicator had the appearance of a metallic arachnid, or, as O'Neill called them, "bugs". The Asgard had discovered them on an isolated planet and taken some for study without understanding the danger they posed. By this time, as Thor said, "They have become a plague on our galaxy that is annihilating everything in its path."
Aboard Beliskner, the Replicators moved in groups through the ship and ingested its structure as raw materials from which to self-replicate. They ignored O'Neill at first, only attacking him, Carter and Teal'c later, when it was clear the humans were a threat. This was a recurring theme of Replicator behavior, that they would ignore beings and technology that were of no use to them, unless they were being threatened by them.
Thor warned O'Neill that the Replicators would be attracted to the energy pulse of the transport technology. Energy weapons were ineffective on them, but SG-1's machine guns and explosives damaged or blasted them apart. SG-1 was able to get past the Replicators' control and send the ship into the atmosphere with a bomb aboard, which they detonated just before escaping. In spite of the massive explosion and entry heat, a single Replicators survived far out in the Pacific. (3.22 "Nemesis Part 1")
The surviving Replicator sank into the ocean and made its way into a Russian submarine. Once there it killed all the crew and then began consuming the sub's metals and replicating itself. Because the materials it consumed were iron-based and not as strong as advanced Asgard metals, the new replicators were a different color and, based on a single block that eroded quickly, more vulnerable. At some point, the original Replicator incorporated itself into a "mother" that was able to very quickly produce new Replicators, although of the inferior materials. Daniel realized that the original Replicator had to be singled out for destruction because of its Asgard materials. Teal'c at his side, O'Neill led a tense battle on board the submarine to destroy the original Replicator. Afterward, Daniel ordered the sub to be blown up with a conventional bomb, destroying all the remaining Replicators aboard and saving Earth for the time being.
Meanwhile, Thor took Carter back to his homeworld to take advantage of the humans' "less sophisticated" approach. Thor explained the true nature of the Replicators, saying: Each individual building block is capable of exerting a reactive modulating mono-polar energy field on other blocks, allowing the replicators to assemble themselves into many forms. To our knowledge, the interior of each block contains the following: 2 million isolated keron pathways. He then explained to a confused Carter that kerons are energy particles that Earth is not yet aware of. Basically, as Carter boiled it down: Each block is like its own individual computer, capable of communicating with the other blocks. Now multiple blocks come together to form bugs and other things in order to perform various tasks, ultimately for the purpose of replicating.
Thor also noted that the Replicators who had taken over some Asgard ships had modified the Asgard weapons technology beyond the Asgard's own understanding. He postulated that they had carried over knowledge from elsewhere in order to do that. This demonstrated how advanced their "collective" intelligence was. Thor also noted that time was not important to Replicators; they thought in very long time scales and were very patient.
Carter suggested using the Replicator's thirst for more advanced technology against them, to lure them to the more advanced O'Neill and then blow it up. Thor was aghast at the idea of blowing up their best ship, and of the risk that the Replicators would disable its self-destruct and assume its technology, becoming stronger than ever. But Carter convinced Thor that since the tactic would be new to the Replicators, they should try it. And, following that plan did succeed in their destroying that swarm and stopping that particular invasion. (4.01 "Small Victories Part 2")
SG-1 did not encounter Replicators again until, traveling far outside our galaxy in Cronus' ship, they found Apophis' ship infested, its Jaffa crew already dead. In the course of the ensuing struggle aboard Cronus' ship, the Replicators learned to control Goa'uld technology. They interfaced with the Goa'uld computers and found there might be more advanced technology on Apophis' base on Delmak; they set a course for that planet. A large swarm of Replicators massed together and created a direct interface to the mothership's propulsion systems. The swarm added power to the hyperdrive and modified it to make the ship travel at 800 times its previous maximum speed, closing the intergalactic distance to Delmak in a matter of hours. Wanting to assure the ship's destruction, O'Neill physically destroyed the sub-space control crystals in order to remove the only way to slow the ship once it exited hyperspace near Delmak. SG-1 and Jacob escaped aboard an uninfested cargo ship, while Apophis and the Replicators burned up on re-entry to Delmak. (5.01 "Enemies Part 2")
Some months later SG-1 found an advanced, humanoid android, named Reese, on a deserted planet. Once awake, Reese said she was created by a human scientist whom she referred to as her father. The SGC soon realized that her planet's civilization had been destroyed by Replicators, which presented the first evidence of them ever having been in the Milky Way. Reese was child-like in behavior. Eventually, she revealed that it was she who had invented the Replicators, as playthings to keep her company. This revelation happened when she created one in her SGC holding room by forming blocks out of raw materials with her hands. She thought of Replicators as her beloved toys, was very protective of them, and initially had complete control of their behavior via her transmitted commands. Eventually she turned against the SGC and let the Replicators replicate unchecked, so that they became deadly and aggressive. In response, Hammond ordered her destruction, and, as a back up, activated the self-destruction sequence for the base. During the struggle, at least one Replicator started to exhibit individual behavior, perhaps indicating a connection to other Replicators elsewhere. With only moments remaining in the self-destruct count-down, O'Neill shot Reese, deactivating her, and the Replicators fell into their component blocks, inert. It is not known if that was because Reese was destroyed or because she had ultimately listened to Daniel and commanded them to do so. (5.19 "Menace")
Human Form Replicators
The SGC gave Reese's body to the Asgard for study. The Asgard formulated a plan to use what remained of her core programming to send a command over sub-space for all Replicators to converge on her location on the Asgard planet Hala. There, the Asgard had prepared a device that would trap the Replicators in a time dilation field. Within the field time would pass ten thousand times more slowly than in normal space, giving the Asgard many years to formulate a new defense against the Replicators. But, the Replicators managed to get to the device and modify it to make time move 100 times faster than normal. By the time SG-1 arrived in the X-303 to investigate (at Thor's request), hundreds of years had passed within the field. The Replicators had consumed all resources on the planet; its surface was completely covered with inert Replicator blocks, perhaps miles deep.
This situation came to be because, just before the time dilation device had activated, the Replicators had advanced toward their ideal: a Human Form Replicator (HFR). First was the name taken by the first one created in human form, and he was the one who modified the time device, thus speeding the HFR evolution by many orders of magnitude.
Human Form Replicators are composed of nanite-sized cells rather than "ungainly blocks." The driving motivation of the first few of them was to create an army within the field and then go forth from it. The small group took SG-1 captive and entered their unconscious minds by moving their hands into the humans' heads. O'Neill and the others were not able to hide their knowledge or memories from this assault, and in fact bad memories were used as punishment if they resisted. After each session, the HFR's would merge with their "brethren" and share what they had learned.
As each new HFR was created, the existing ones would try out different programming on it in order to achieve advancement of the "species." In the case of Fifth, they enabled more human behavior and even empathy. This caused Fifth to be less ruthless than the others, who came to consider him a mistake. Fifth felt isolated and vulnerable; he believed Carter when she said SG-1 would take him away in exchange for his help. Under orders from O'Neill, Carter lied to Fifth and tricked him into helping her set off the device. SG-1 escaped, leaving all Replicators in a field that would advance only 1 year for every 10,000 years in normal space-time. (6.12 "Unnatural Selection")
The degree of time dilation was not enough, however, and the Asgard knew they had bought themselves less than two years before the HFRs would reach and deactivate the field. In that time, they collapsed Hala's sun into a black hole, with the aim of seeing Hala sucked into it and destroyed. Carter and Teal'c became trapped in its gravitational field when they arrived looking for an Asgard who could help awaken O'Neill from stasis in Antarctica. Thor rescued them just as their ship was destroyed.
The black hole destroyed the planet Hala as intended, but many of the Replicators had left the planet and formed a coherent mass that was able to remain beyond its event horizon. Then, while Thor, Carter, and Teal'c watched from aboard Thor's ship, the Replicators used the time dilation device to counteract the gravitational effects of the black hole, so that they were actually able to move away from the event horizon. They pursued Thor's ship, infested it, then stole Carter from it before entering hyperspace in the ship they had created.
Thor guessed the HFRs were headed for the new Asgard homeworld, Orilla, because neutronium was plentiful there, and the element is required for creation of HFRs. So Thor and Teal'c headed for Orilla.
Meanwhile, Carter had become the prisoner of Fifth, who was by now mentally unstable as a result of his programming and Carter's earlier betrayal of him. He described himself as having evolved beyond his brethren by having emotions and wanting more than to replicate. He tortured Carter by entering her mind and causing her pain, but started to feel compassion after seeing her suffer. (8.01 "New Order Part 1")
The Asgard destroyed Fifth's ship as it approached Orilla. Replicator blocks from the ship rained down on the planet, threatening the Asgard on their new homeworld. Fifth and Carter escaped the ship's destruction and moved inside inside a Replicator structure on the planet, near a vein of neutronium that could be used to create more HFR's. Fifth changed his strategy with Carter from torture to coercion, trying to convince her she was living happily on a ranch with Pete Shanahan. Carter never fully believed the ruse, and Fifth revealed himself and admitted to Carter he loved her. At the same time, Fifth was remotely controlling the Replicators on Orilla to attack key Asgard systems and of course to replicate.
Meanwhile, aboard Thor's ship, a rescued O'Neill used his Ancient knowledge to build a hand-held weapon capable of destroying any sort of replicator by disrupting all communication among its cells, rendering each one inert. Thor was able to create a planet-wide version of the weapon that would destroy all Replicators on Orilla. On the planet, Carter convinced Fifth she would never love him or accept the false reality he had created. Fifth freed her to be found by the rest of SG-1 and escaped the planet just as Thor used the disruptor weapon successfully on all Replicators in the area. But Fifth had collected enough neutronium to create the next best thing to Carter: a Human Replicator in her form to whom he would transfer all of his knowledge and memories. His aim was them to rule side-by-side, to find a new home for the Replicators, to be unstoppable. (8.02 "New Order Part 2")
This "Replicator Carter" proved a formidable foe indeed. Fifth taught her everything, including all he knew of Samantha Carter and the memory of her betrayal of him. She was devious, manipulative, and completely free of the conscience that Fifth had, which she considered nothing but a weakness. Using her knowledge of Carter's experiences and thought processes, Replicator Carter talked her way into the SGC's Alpha Site. She used the pretext that she wanted to be destroyed after first helping the SGC adjust their disruptor weapon to work against what she claimed was Fifh's counter-weapon cipher. She claimed she was off the "link" to the other Replicators and knew only that they were headed for the Milky Way under Fifth's command.
In fact, she was lying about everything, risking her continued existence in the calculated belief that Carter would react as she'd predicted and not allow her to be killed. And Carter did so, repeatedly arguing that Replicator Carter shouldn't be destroyed yet and allowing her to develop what she claimed was the counter-counter disruptor weapon algorithm. With consent from the SGC, Carter allowed Replicator Carter to upload the algorithm to the disruptor-equipped satellite provided by the Asgard.
Replicator Carter in fact was playing Carter as well as Fifth for fools. Her true objectives were to kill Fifth, disable the disruptor weapons technology for good, and assume leadership of the Replicators in preparation for an assault on our galaxy. All of this she managed to do. She used the Asgard weapon to destroy Fifth's ship, then used the satellite to upload a disruptor-blocking cipher to the Replicator link, also making herself impervious to the hand-held weapon Teal'c had been using to keep her in check. Finally, she escaped through the Alpha Site's Stargate, presumably to rendezvous with her brethren. She left behind a piece of her 'arm', but its cells were inert. Carter was remorseful for having trusted Replicator Carter, noting the Replicator had learned betrayal from Fifth, who had learned it from her. (8.11 "Gemini")
Some months later, her forces now incredibly numerous, Replicator Carter made her move on the Goa'uld. She killed Lord Yu personally and sent a ha'tak to take Daniel Jackson. Her Replicator forces moved on all Goa'uld ships in the galaxy, destroying or taking them by the dozen. Jacob predicted the Goa'uld could be wiped out in a matter of weeks. Deciding the risk was worth it, Thor and Carter reactivated the 'arm' and its link to the Replicator communications network. From that they were able to see the locations of the Replicators in our galaxy and to develop a counter-agent to the cipher that prevented the disruptor from working. They were successful in destroying a nearby Replicator ship, but the Replicators very quickly adapted to the weapon and became immune again.
Daniel fell into Replicator Carter's hands, just as Carter had fallen into Fifth's. In spite of Daniel's agreeing to answer any of her questions, Replicator Carter invaded his mind to "dig deeper." She recreated a tent-like setting and came to him in the guise of Oma Desala, hoping to elicit from him his ascended memories. At first, Daniel believed she was Oma, but he soon saw through her unenlightened behavior. Replicator Carter revealed herself within Daniel's false reality. She had already gotten what she needed from Daniel: an image of the Temple on Dakara, where an Ascended Daniel had known there was a Ancient weapon that could destroy the Replicators. (8.16 "Reckoning Part 1")
At the same time, the SGC also learned of the weapon on Dakara, understanding it was capable of destroying all life in the galaxy. They made it their mission to destroy it, but soon realized it was not so different from the Ancient disruptor and that it could perhaps be used against the Replicators. They set to work on it.
Replicator Carter, still holding Daniel prisoner, had seen enough of Daniel's knowledge to know how much he held and what she could do with it, including destroy Anubis. She tried various tactics to get him to cooperate with her, but he refused. She continued the mind probing in spite of his resistance, transmitting what she learned from him to her brethren Replicators. But the information required a level of understanding that a 'machine' such as she could not fully process, and she was strained by the attempt.
Simultaneously, the Replicators launched an attack on the SGC, even though Replicator Carter had promised a skeptical Daniel that she would not harm Earth.
Daniel used the bits of Ancient knowledge he was being exposed to and Replicator Carter's distraction to read her mind and even find pathways to control the Replicators. When Replicator Carter tried to break the link to Daniel's mind, he held her inside it, calling it "Danny's World."
The Replicators moved in on Dakara as well, even as Carter and Jacob, with Ba'al's help, were making final adjustments to the weapon to make it work against the Replicators.
Both the Dakara situation and that of O'Neill and others at the SGC was desperate, with only moments before the Replicators destroyed both. Daniel asserted control of the Replicators against Replicator Carter's will and was able to stop them all for a few moments. Then, Replicator Carter reasserted control and emerged from Daniel's mind so that they were back in her ship. She immediately stabbed him through the chest, dealing him a mortal wound.
But the extra time bought by Daniel's intervention was enough for Carter and Jacob to activate the Dakara weapon. It connected to all Stargates in our galaxy and fired, killing all Replicators everywhere in the Milky Way, including Replicator Carter. Daniel's spirit was rescued by Oma just as Replicator Carter's ship was destroyed. This marked the end of the Replicators in the Milky Way galaxy. (8.17 "Reckoning Part 2")
- Reese - Reese was an artificial lifeform who in turn created the first, mechanical-form replicators
- First - the first Human Form Replicator
- Fifth - the Fifth Human Form Replicator, who was programmed with more emotion than his predecessors
- Replicator Samantha Carter - a Human Form Replicator created by Fifth in Carter's image, who wiped out many System Lords and nearly took control of our galaxy
- As far as we know, the Replicators did not form alliances with any other civilizations.
- Asgard - They nearly lost their civilization to the Replicators and eventually allied with the humans of Earth to defeat them.
- Goa'uld - The Replicators saw the Goa'uld as an excellent source of new technology and came to the Milky Way to harvest it. The Replicators wiped out many System Lords before they were destroyed. Indirectly, the Replicators helped free the Jaffa.
- SGC - Through their alliance with the Asgard, the SGC was exposed to the Replicators. The SGC discovered Reese, their creator, and earned the hatred of the Human Form Replicators when they helped the Asgard try to contain them.
An alliance among the Asgard, Goa'uld, and SGC was necessary to finally defeat the Replicators in the Milky Way.
- 3.22 "Nemesis Part 1"
- 4.01 "Small Victories Part 2"
- 5.01 "Enemies Part 2"
- 5.19 "Menace"
- 6.12 "Unnatural Selection"
- 8.01 "New Order Part 1"
- 8.02 "New Order Part 2"
- 8.11 "Gemini"
- 8.16 "Reckoning Part 1"
- 8.17 "Reckoning Part 2"
- Brig. Gen. Jack O'Neill
- Dr. Daniel Jackson
- Maj./Lt. Col. Samantha Carter
- General George Hammond
- Jacob Carter/Selmak
- Oma Desala
- Pete Shanahan
- O'Neill-Class Ship
- Stargate Command (SGC)
- System Lord
- Technology of the Asgard
- Weapon On Dakara
--Michelle 19:58, 7 January 2007 (PST)