At the end of Mass Effect 2 we see the Reapers outside the Milky Way approaching and during Mass Effect 3 in the Galaxy Map they seem to appears on the edges and make their way inward.

I am wondering, do the Reapers just sit and wait outside the Milky Way wanting for the next cycle to begin or is there any Galaxy's outside the Milky Way which the Reapers attack as well?

4 Answers 4


Reapers sleep in the dark space somewhere outside the Milky Way galaxy. Then they attack the Milky Way galaxy. That's all we know for sure (so far). Other galaxies are never mentioned.

There is a similar discussion at the Mass Effect (wikia) site, but there are no definitive answers there either; just some good guesses based on what we know and don't know about the Reapers. But if you're interested in theories without Bioware backed lore, its a good read.

For what it's worth, it is my guess that they might operate in other galaxies too, but probably don't. It depends on if Bioware wants to expand that much. They haven't written themselves out of that possibility, but I doubt they'll need to go that far; there are lots of stories left to tell in this galaxy.

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    Three years later, Mass Effect: Andromeda is released... told in a new galaxy. I guess the BioWare writers do need to go to other galaxies to tell stories. Though I still posit there's more left to say in the Milky Way. :-)
    – Mufasa
    Commented Mar 9, 2017 at 22:59

From what we know of the Reapers, it was mentioned that they go into hibernation for 50 000 years to conserve energy in dark space (presumably the space between galaxies). How far outside the Milky Way they are is unknown, but they are likely near its edge (far enough to not be discovered, but close enough to get there on their own).

I don't think it was ever hinted the Reapers do the same to other galaxies, though I suppose it might be possible.

Furthermore, their regular FTL drives would not be fast enough to get them anywhere close to Andromeda for example, especially because they need to conserve their energy supplies.

If I am not mistaken, the Reapers have a maximum FTL speed of 10 000 times LS... meaning that, the Reapers would need about 270 years of continuous travel (and energy expenditure) to get to Andromeda.

I don't think they can do this without expending most of their energy reserves in the first leg of the journey and finding other means to replenish (which might be possible if they can find something in the void between galaxies... though they'd need something akin to Trek's bussard collectors that are absorbing background radiation, etc. from subspace and normal space to generate energy - in the absence of this technology, the Reapers would likely need to create something like that to keep them self-sufficient, and we don't know if their programming allows them to go for that, considering their sole focus on the 'great experiment').

What they COULD consider doing is building a sufficiently large Mass Relay (unless they can use the Citadel itself) that could catapult them close to Andromeda, where they could build a connecting Mass Relay.

However, I doubt the Reapers are operating in other galaxies. After the Leviathans were turned into the first Reapers, there hasn't been a single mention or any indication that they were interested in other galaxies (which makes the Reapers a bit stupid to be honest... you have a proverbial universe to explore and you want to participate in an endless repetitious cycle of extinction for millions upon millions of years with technology that doesn't really advance?).


The Reapers live in the dark space between galaxies. It's not told if they actually watch over any other galaxy but the Milky Way, but it's highly unlikely, because de intergalaxy distancies are waaay waaaaay bigger than the intestar spaces.

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    not really that much bigger - Andromeda is something like 20 times further away than the Milky Way is across, so if the Reapers can cover the whole Milky Way in a human lifetime, they can easily cross over to other galaxies in the tens of thousands of years they have been waiting. Commented May 26, 2014 at 21:41
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    Within the Milky Way the Reapers have access to the mass relays to jump instantly over the long, uninhabited distances between star systems; we have no idea how long it took them to build that relay system, but it would have to be at least 100,000 years (they'd have to cross at sub-light speed at least once to build a relay). And it would take at least 2.5 million years for one of them to reach Andromeda to set up a relay there.
    – KutuluMike
    Commented May 27, 2014 at 17:20

The Reapers intelligence is bound by their programing from the Catalyst & the Catalyst is bound by the programing of the Leviathans. As commented on by the Leviathans = the catalyst/reapers are fulfilling their original purpose. It might not be what the Leviathans had wished but it is fulfilling their purpose and not radically different from such thus the Catalyst/ Reapers can only twist their original programing not completely change and or abandon it.

Thus the Catalyst/Reapers are only concerned with the Biological Vs Synthetic problem within the Milky Way galaxy since the Leviathans never spread out beyond The Milky Way. Being "Apex species" thus not feeling threatened in anyway necessitating the need to spread to other galaxies made them myopic and self centered and them creating myopic & concerning the Milky Way galaxy only creations

  • Whilst this seems like some nice reasoning do you have any evidence for it you can edit in to support your case?
    – TheLethalCarrot
    Commented Feb 28, 2019 at 8:28

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