I was rewatching Stargate-SG1 and noticed something while I was watching "Menace" where we learn that the android Reese created the Replicators and sent them out in to the galaxy.

We know that the Replicators integrate technology they consume to their own and lastly we know of no race that were capable of travelling between galaxies (and that lives in the Milky Way) aside from the ancients

My question is, how did they end up in the Asgard galaxy (Ida) and why didn't they consume everything in the Milky Way long before the series began?

Is is ever explained?

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  • 4
    I'm not sure why the close vote. I've improved it a little by adding a link to the episode Frozendragon's referring to but the question seems very clear and worthwhile.
    – Valorum
    Commented Feb 8, 2014 at 14:04
  • @Richard - I'm guessing English. I'm VTCOing in the review queue, especially after your edit Commented Feb 8, 2014 at 14:51
  • @Richard - that's me forgetting how to spell "keep" :) Commented Feb 15, 2014 at 8:31

6 Answers 6


The short answer is that it's not explained in canon. Although the Asgard have had a presence in the Milky Way Galaxy for a very long time (and hence it would be logical to assume they encountered the Replicators there) Thor explictly states that they were first encountered in the Ida Galaxy.

THOR : They were discovered on an isolated planet in our home galaxy some years ago. The creators were not present.

TEAL'C : Most likely destroyed by their own creation.

THOR : The Replicators were brought aboard an Asgard ship for study before the danger could be fully comprehended.

O'NEILL : We do that all the time. I kinda expected more from you guys.

THOR : Overconfidence in our technologies has been our undoing. The entities learned from the very means that were employed to stop them. They have become a plague on our galaxy that is annihilating everything in its path.

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    Since we know from Stargate: Atlantis that an entirely different civilisation of Replicators were also built by the Ancients, presumably separately, it could just be that Reese's Replicators and the Ida Replicators have no direct link.
    – evilsoup
    Commented Feb 8, 2014 at 15:31
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    @evilsoup - The Asurans (portrayed in Atlantis) bear only the most superficial similarities to the Replicators in SG:1. It's far more likely that the Replicators found in Ida came from the Milky Way since they're completely identical. I assume they hitched a ride on an Asgard ship or followed them in an Ancient ship.
    – Valorum
    Commented Feb 8, 2014 at 17:41
  • @evilsoup if they had no direct link they wouldnt have been able to reverse engineer the source code for the ida replicators from reese
    – severa
    Commented Feb 9, 2014 at 3:43
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    @sumbuddyx - You are of course correct.
    – Valorum
    Commented Feb 9, 2014 at 9:48
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    @evilsoup - Because the Milky Way replicators created by Reese and the replicators we see in the Ida galaxy are completely identical. By comparison, the Pegasus "Asurans" are merely called 'Replicators' by the Atlantis crew because they share similar characteristics. Later we see that there may be a crossover due to the fact that they also use the horseshoe-crab type replicators. The AR guns work on both because the techology (Kuon-based) is similar
    – Valorum
    Commented Feb 9, 2014 at 11:04

Officially there is not explanation about how they are even connected let alone how they left the Milk Way for the Ida galaxy and why the Asgardians didn't knew about them before. For the most part everything about the Milk Way Replicators are just but pure speculation by fans. Only the Asurans had a background explained. Reese's appearance made no advancement in explaining who was responsible for the Replicators, they just added a new robot to be the source of the other robots but who created the first robot, Reese, still remains unknown.

But I've always wondered how it would be possible to explain their similarities and the fact the Ancients had an specific weapon to destroy Replicator blocks.

This is my idea in how it could have happened in any way this was explained in any type of media;

I think Reese was created by an Ancient scientist who lived in the Milk Way before the plague. Much like we saw in other instances, the Ancients had worked with many different researches over their time in our galaxy and some of them didn't function properly or were at very early stages of development such as their time technology as seen in Window of Opportunity. For me, Reese was created with the purpose of researching in how to build an advanced artificial being. The Replicators could have been intentionally part of her project, a robot who could create new robots such as some algorithms we have in real life computing which can evolve and develop new and better algorithms than the original ones, such as Evolutionary Algorithms and Genetic Algorithms or they could have been an unintentional byproduct of her design, since she was clearly created to act and think like an organic being.

She then lost the control of her Replicators and they made a mess in the city but eventually the Ancients or the Ancient responsible for Reese created the disruptor or an predecessor of this technology and ended the Replicator uprising. This would also explain why they found Replicator blocks lying around the planet. Reese's father then decided to put her to sleep, because he/she didn't wanted to lose the project. It wouldn't be the first time an Ancient hid a project which other Ancients decisively disagreed with the progress, such as the Time Jumper by Janus. It's also possible those hypothetical Ancients living on Reese's planet had achieved a way to input a code into the hive-mind of the Replicators making them, the Ancients, not a target as they did with the Asurans.

During the Ancient-Wraith war, it's possible they decided to revive the project, already knowing how to stop the Asurans if needed and also how to control them direct on their programming, seemed to be a nice idea. Nonetheless, again the Replicators started to generating trouble when they adapted and decide to kill humans in order to get rid of the food source of the Wraiths and were shutdown again as we know.

The Ida galaxy Replicators could have travelled with an Ancient ship. If the idea of the Ancients from Reese's planet had achieved a way of making themselves invunerable to the Replicators, a single entity could have survived and travelled with the Ancients during one of their trips to Ida, which probably happened a lot since they and the Asgard were in an Alliance. This would explain how a Replicator could travel in an Ancient ship and not attacked it, since it wouldn't have a taste for anything Ancient because of their programming. It is also possible some Ancient had decided to bring the project to Ida galaxy in order to continue it without the others knowing.

I like to think that's what happened, it makes sense in my head. I know probably the Asurans were added because they wanted something like the Replicators back and didn't care much about the connections.


reese's planet was an ancient outpost for a small civilisation living in Ida, thus explaining the lack of other ancient tech. The people tried to evacuate home to The Ida Galaxy, but the replicators followed them and killed them anyway consuming all the ancient tech they could, the ancients tried to destroy what they can and so all the replicators went through in order to get as much as they could. This gives them a head start on the Asgard making it harder for them to contain/beat them. The ancients destroy the stargaze to late, allowing all the bugs through but essentially trapping them in Ida. Fan explanation, but not contradicted anywhere to my knowledge.

  • Do you have a reference for your claims?
    – AncientSwordRage
    Commented Apr 3, 2016 at 12:20

Expanding on one of Richard's comment above, an alternate, and bleak, explanation surfaces:

After lotusing Reese's planet, the replicators set out to search for food elsewhere.

At this point they encounter the Ancients, and integrate their technology and philosophy (to some extent) into their own.

Recognizing that Ancients pose a threat to their immediate dominance, they do the machiney thing and use their new-found hyper drives to colonize every galaxy the Ancients know of but are not present in, explaining their presence in Ida, and their absence in Pegasus and the Ori Home Galaxy.

In other words:

The entire universe is overrun by replicators, except the Milky Way, Pegasus and Ori Home galaxies.

  • 1
    Fan fiction but quite plausible.
    – Valorum
    Commented Feb 10, 2014 at 12:14
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    @Richard: More of a fan theory. Recall what happened the first time Samantha Carter blew up a solar system: Their ship, as well as that of Apophis was flung far afield, where they encountered the replicators, despite being in the ass-end of nowhere. In 05E01 Enemies they are 4 million light years out, and only a mass exodus of replicators in ancient (Ancient) times can account for their presence here. Commented Feb 10, 2014 at 12:27
  • This is less plausible given that they never run into replicators in Stargate: Universe.
    – Paul
    Commented Feb 10, 2014 at 16:31
  • @Wil Wasn't the Ida galaxy 4 million light years out?
    – Kvothe
    Commented Feb 10, 2014 at 17:09
  • @Kvothe: Yes, approximately. But there are a lot of galaxies that are 4 million light years out. Commented Feb 11, 2014 at 7:04

The answers are not in any single episode or any single show. You really have to watch Stargate-SG1 and Stargate-SGA (Atlantis) in their entirety to come to the conclusion.

The Ida Galaxy is the Asgard designation for the Pegasus Galaxy which is the Terran designation for the next closest galaxy in our local cluster.

The Events of SG1 took place primarily in the Milky-way Galaxy until the events of the Ori took them to another galaxy that has never been pin pointed.

The replicators were creations of the Ancients (Au-Terran's) which as we all know was the first human species to evolve in any Galaxy that we know of to date, not counting the races in the Great Alliance and others seeded by the Ancients.

Thus we can determine that the Replicators never left the home galaxy, in fact After the Ancients created the replicators they sent them forth to attack the Wraith, after years of war the Wraith found the shut down code for the replicators, this is not before the events of the Ancients realization that the replicators would never be the weapon they intended and attempted to destroy them. In fact they closely destroyed their world but a few cells survived and continued the primary directive.

The true question is how the replicators (Reese) got from the Pegasus/Ida Galaxy got to the Milkyway. More then likely the replicators stowed away on either a Asgard ship or an Ancients ship, as both races being in the so called "Great Alliance" had inter-galactic hyper-drives landed on the closest planet and continued.

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    The Ida and Pegasus galaxies are not the same. The Ida galaxy is the Asgard home galaxy, and the Vanir split from the rest of the Asgard and moved to the Pegasus galaxy. I'm not sure of the source of the information but the wiki lists Pegasus as 3 million light years away, and Ida 4 million.
    – M_the_C
    Commented Oct 2, 2014 at 19:54
  • I thought, that there were 2 distinct and separate places where replicators were made: In Peguasus galaxy they were created by Ancients. They didn't move anywhere from there and were ultimately destroyed during SG:A series, this 'though' may be enforced by often describing them (Pegasus's Replicators) as rather stale, unwilling to take actions, develop and explore (mentioned I believe when it was explained why didn't they develop better technology than one the Ancient had at time of their creation)
    – Hary
    Commented Oct 2, 2014 at 22:41
  • 2nd 'race' of Replicators was constructed in Ida galaxy and during SG-1 brought to Milky Way one. They were the expansive and searching ones, also I think, primitive at start, though to the point when they managed to create human-form when in time-dilation field IMO there is no direct connection between those 2 forms of replicators
    – Hary
    Commented Oct 2, 2014 at 22:43
  • "Au-Terran" isn't anything. Did you perhaps mean Lantean?
    – Izkata
    Commented Oct 2, 2014 at 23:17
  • @Hary There are 3: The two you describe, and the ones this question asks about. The ones in this question happen to look identical to the primitive form of the Ida galaxy ones, hence the question about a connection
    – Izkata
    Commented Oct 2, 2014 at 23:18

One of the anicent warships in orbit of the replicator planet in Pegasus gets a hitchhiker just a few Nanites nothing that would show up on the scanners the ship leaves orbit and sets course for the Milky Way and arrives at Reeses planet where the cells having been exposed to the vacuume of space thaw as the ship enters the atmosphere and migrate to the planet.

Ff a few thousand years[Sic] the Goa'uld finding an anicent city hoping to find some tech they can manipulate/steal and transplant humans to the planet. Ff again the humans having overthrow their Goa'uld masters (like the Galarns backward engineering the memory devices) find an amount of Nanites in a Goa'uld research lab after the damage caused by the ancients trying to destroy them, leaving the replicator planet and entering resses planet as well as exposure to deep space are unable to replicate. Using the Goauld research Resses father creates Reese based on the Nanites terminator style (building a working android from research into tiny machines not the time travel bit that's just silly....) and the rest we know.

This bits a reach. Some of the replicators make it through the gate to a protected planet aren't beamed away by thorns hammer resses instruction is protect me so the desire for the most powerful tech is paramount and interface with the technology where they find the location of IDA seeing the delicious Asgard tech leave on mass and create the beachhead, having some of their number beamed away by the asgard for experimentation in an attempt to forfull resses order take on the replicate at all costs concept explaining why the didnt just stay in the milkyway and overwhelm it, and the asgard wrongly assume they are native to Ida due to their numbers everything after that we know.

  • 1
    This seems extremely speculative. There's no evidence of nano-scale replicators in SG1 until much, much later on.
    – Valorum
    Commented Nov 12, 2014 at 20:47
  • Of course it's all completely speculative it's a theory to try and fix gaping plot holes.
    – Fionntán
    Commented Nov 12, 2014 at 20:52
  • 2
    You'll find that theories without basis tend to get voted down, especially when they contradict the show itself.
    – Valorum
    Commented Nov 12, 2014 at 20:53
  • It doesn't contradict the show because the show doesn't provide any background.
    – Fionntán
    Commented Nov 12, 2014 at 20:59

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