Stellaris – Highly Competitive Assimilator Guide (With Pictures)

This beautifully formatted guide serves as a way to min-max with the driven assimilators and rush your neighboring empires in the first 30 years which will at least double the amount of pops you have, then repeat the process and snowball quickly. With this playstyle, I tend get around 500 pops by 2280 or earlier (Pictures included for proof).

Guide to Highly Competitive Assimilator

Beginning Empire Setup

Note: The “What this Does” section is only for newer players so you can skip if you only want the main tips and not the extra explanations.

Empire Type

To begin, go to the the Governments and Ethics menu (1), press Gestalt Conciousness (2), then select machine empire (3). Also, in the civics menu, click on Driven Assimilator and Rapid Replicator (4).

What this does (Skip if you are not new):

  • Rapid Replicators increases base population growth of your robots, which helps in the earlygame until we find other populations to conquer.
  • Driven Assimilator gives you the ability to assimilate other species into cyborgs.
  • Cyborgs are mind-controlled and cannot revolt which makes this more powerful than normally conquering them.


Now go to Cyborg Species Traits (1). Select Industrious, Weak and Deviants. If they are not lithoids, add the Rapid Breeders trait; However, you can alternatively pick lithoids for the habitability boost if you have the DLC (This will be important later). (all traits shown as 2 on righthand side in photo)

What this does:

  • Industrious gives you extra minerals which are one of the most important resources as they are used for construction and making alloys which will give you more military power and later on, megastructures if you have the Utopia DLC.
  • Deviants makes the species dislike the government, however, as mentioned earlier cyborgs are mind controlled and cannot revolt so this essentially gives us a free trait point with no risk.
  • Rapid breeders increases population growth, and lithoids increases habitability, either of which are very good.
  • Weak reduces army power and gives a very slight resource debuff but this isn’t important as you can just build more armies and technologies you research soon after game start can negate the debuff on resources

Next, press on the main robot’s species traits just above the tab you already clicked on earlier, add in Power Drills, High Bandwidth, and Mass Produced.

What this does:

  • Mass production adds more pop growth.
  • Power drills adds more minerals.
  • High Bandwidth adds more empire sprawl, but this won’t matter much earlygame and by midgame you just want to try to outscale it.


Finally, the origin you should select is the Doomsday origin. After 35-45 years your homeworld will explode. However, until then, you will get enormous resource bonuses, that begin with 30% more minerals, energy and alloys and going up to 120% which gives all the resources you need to relocate and conquer other empires within only 30 years of game start. It reduces habitability over time, but this doesn’t matter much as we’re using machines.

Earlygame Pre-Contact Playstyle

The general playstyle will focus on Minerals as the starting resource, Alloys and Tech as close seconds, and Energy Credits mattering third (In case of deficit, switch the order around).

Tryhard Strategy for Starting Resource Production

When you begin, open the ship designer using F9 or the menu on the left. Untick the “auto generate designs” button on the bottom left, press on Corvettes, and remove all components that can be removed, then press Save. By the end, it should look like this if you did it right:

Now click on the starting corvettes and press Upgrade. This will give you an extra 145 alloys or so. Proceed to sell all your alloys and buy minerals with them instead. Now click on your homeworld, and build mineral districts. Send science ships to survey different systems in the meantime as they are being constructed. Also, click on Policies and set default borders to closed.

When they finish, go to your homeworld again and press the Population tab on the bottom. Click on the arrow on the top right next to Menial Drones, then press Minus a few times near the Maintenance Drones. We have a surplus of amenities on the planet this early on, so you can use those pops to generate more minerals instead of amenities.

When amenities dip below 0, increase the open jobs and/or build nexus deposits to get more of these jobs if you already have these jobs open at max. This should help prevent unstability. Lastly, make sure to build more science ships and employ more scientists and send them to survey.

Keep repeating this process until you make around 100 minerals a month (Should happen within the first 10 years). At this point, start to build Alloy Districts on your homeworld, and some unity buildings. Employ scientists on ships when you can, and colonize new worlds that have enough natural resource deposits (I.e minerals and energy) using your robots which will adapt to the environment. Make sure you build Machine Asembly plants there to increase pop growth too.

The Attack of the 40 Foot Cyborgs

If you find primitives, build armies on your main world and then land them on the primitive world to begin assimilating. You can change the planet setup (districts, buildings etc.) after that. This will be a great boon and a good indicator of how you can snowball.

Earlygame Post-Contact Playstyle

Typically by around 15 years you will have met alien ships. You will not have any intel on them or method of communication. As most aliens are hostile to assimilators, I typically prefer to wait for them to decrypt my language; Doing it myself is the kind of thing I like to call, “tempting fate.”

Target Located. Assimilation Protocols Activated

Before they contact you (it will take a number of years), begin investing in more alloy districts on your homeworld and research labs on your other worlds. You will now start to need more energy districts too, in order to focus on the militaries you are going to build soon. If you conquered any primitives, feel free to resettle them around to help support these jobs (If the habitability is high enough).

You should also build starbases and military defense platforms around chokepoint systems on the direction of the aliens.

After they contact you, consider the type of empire. If it’s a hivemind or machine empire, just try to improve relations and bribe it enough to go away as you can’t assimilate it and it will be a resource drain to fight it. If it’s a devouring swarm, you may wish to restart on a new game because evidently you didn’t have much good luck. If it’s a fallen empire, leave it alone. But if they are organic non-gestalt pops then you’re in luck!

Go back to the ship designer and either make your own ship designs or turn on the automated design. Now start building many military ships with the alloys you stockpiled (If it’s very earlygame e.g before 30 years, several dozen corvettes will be powerful enough to conquer most other empires except advanced starts). Send the ships to the chokepoint near your borders, and declare war. After defeating the main fleets of the enemy, you can split up some fleets (Anything above 1.5k will usually be able to fend for itself by this point unless you’re playing on high difficulty) and put them in the same systems as the enemy worlds you want to take, then send armies to conquer them. Repeat this process until you take all their worlds or until war exhaustion forces you to stop.

First Alien Homeworld Conquered!

Woohoo! Now we should have at least doubled our population. After a few years all the pops will be assimilated into our workforce. Now you can do the same building methods as before, and then repeat the same process with other neighbors; Doubling, tripling, quadrupling and so on to our workforce.

It’s Moving Time!

Ok, so it’s quickly approaching thirty years, and you have to evacuate your homeworld. It’s not as difficult as it seems.

If you conquered other worlds, you probably have energy districts and unity buildings like mentioned before. Simply distribute your pops around these worlds and build districts/buildings on them for new jobs. You’ll use only a bit of unity and energy compared to your total stockpiles. There we go! Now that your empire is widely split around and distributes production and population on several different worlds, it’s difficult for any empires to pin you down with just conquering a few systems; If you continue using choke points, building your military, and so on, you will soon become unstoppable.

Micromanagement Tip

If the micromanagement bothers you, do not use the planetary or sector AI. It is very bugged. Instead, by using your mineral stockpiles, you might want to just build districts ahead of time and prioritize jobs using the population menu and add buildings when the slots open up.

Proof of Concept in a Multiplayer Run

In a multiplayer run with my friend, I have been testing this build (I have done so several times before then in singleplayer). Here are some photos of the stats by only 87 years ingame. Notice the amount of monthly resources and the amount of pops (570!).

Egor Opleuha
About Egor Opleuha 7096 Articles
Egor Opleuha, also known as Juzzzie, is the Editor-in-Chief of Gameplay Tips. He is a writer with more than 12 years of experience in writing and editing online content. His favorite game was and still is the third part of the legendary Heroes of Might and Magic saga. He prefers to spend all his free time playing retro games and new indie games.


  1. This is an excellent guide. As someone with a bit of experience with this type of build, it gave me more information and ideas. I would love to see a Necro build. Great job!

Leave a Reply

Your email address will not be published.