Welcome to the Stellaris in-depth colonization guide. Colonization is everything in Stellaris. In fact, Stellaris is a colonization game. You claim stars and colonize world in order to build your empire.
Very first thing to consider before colonizing a new world is the planet habitability. Because habitability will determine what you get from the colonized planet.
%80 habitability penalties:
- Pop amenities usage: +20%
- Pop upkeep: +20%
- Resources from jobs: -10%
- Pop growth speed: -10%
%60 habitability penalties:
- Pop amenities usage: +40%
- Pop upkeep: +40%
- Resources from jobs: -20%
- Pop growth speed: -20%
%20 habitability penalties:
- Pop amenities usage: +80%
- Pop upkeep: +80%
- Resources from jobs: -40%
- Pop growth speed: -40%
As you can see, planets with low habitability suffer insane number of penalties. Okay, but what determines the habitability?
Climate will determine planets habitability. Any planet with less than %60 habitability does not worth colonizing. Even %60 habitability planets are not always worth it. You need to build gene clinics on them to increase habitability. Habitability bonus technologies are also worth researching as early as possible.
All in all, colonize green planets ASAP. Decide to colonize yellow planets with gene clinics or terraform them into your main species planet preference. And never colonize red planets. Low habitability planet is a liability. To go deeper, check out the latest Stellaris habitability guide. Habitability is a very unique and deep mechanic, Stellaris did a pretty good job with it.
Early Colonization
Early colonization is highly important to start building your economy, growing pops, and snowballing.
There are always two guaranteed habitable worlds (two very close planets with the same planet class as your homeworld) unless you edit Stellaris default galaxy settings. Those two planets will have 80% habitability and must be colonized immediately. Need to start breeding pops ASAP.
Again, always colonize gaia and relic worlds because they’re too good to pass.
Now let’s discuss what’s called Stellaris breeder worlds / feeder worlds. Breeder worlds are empty planets with no districts or buildings whatsoever. Only purpose of them is to breed new pops so that you can re-settle them to a specialized production planet. This is an advanced player tactic and requires some micro-managing. So, don’t bother with it unless you’re playing on higher difficulties.
Expansion Planner
Expansion planner is the perfect colonization tool. It’ll list all the surveyed planets and their habitability, sizes, districts, features, etc. Can colonize planets via expansion planner with a single click. Expansion planner also list terraforming candidates which is another useful feature for the mid-late game.
Stellaris expansion planner hotkey: F8.
You can always manually build colony ships and manually colonize planet. However, once your empire grows wide, it’s very hard to find planets inside your borders. That’s when the expansion planner becomes important.
I usually use expansion planner to find planets with very high energy districts because that’s something precious and rare.
Colony Ships
To colonize new worlds, you need to build colony ships and move them safely to their destination. Luckily colony ships do not cost pops, they only resources.
Building a colony ship will cost 200 of three basic resources for regular empires. For gestalt consciousness its 200 / 500. Not really costly except for the very early game when you’re trying to rush colonizing guaranteed habitable planets nearby your homeworld.
Pro tip: You can prebuild colony ships from your shipyard and direct them whenever you find a suitable planet. That way you can save a lot of time because colony ship build time is 360 days which is very long.
Always build colony ships with your main species. You don’t want to spread some random species with bad traits across your empire. Stellaris best species traits guide will help you get the most out of your main species.
Unique Worlds
All unique worlds in Stellaris:
- Ring segment: %100 habitability. Unique districts, best world type in the game.
- Ecumenopolis: %100 habitability. Unique districts, +20% resources from jobs, +15% pop growth, +15% pop assembly, and all building slots unlocked, second best planet type.
- Machine world: %100 habitability. No district cap, flat %10 production bonus, unique coordination district, -10 pop housing usage, +1 replicator job, all building slots unlocked.
- Hive world: %100 habitability. +10% resources from jobs, +1 spawning drone job, +6 housing from hive districts, all building slots unlocked.
- Relic world: %80 habitability. (Can be turned into ecumenopolis without any tech or perk requirement.)
- Gaia world: %100 habitability. Flat %10 production bonus, +%10 happiness.
- Tomb world: %0 habitability.
- Nanite world: %100 habitability. Nanite production. (Only for machine empires who took nanite ascension path.)
Some unique worlds are located inside unique systems in Stellaris. Wenkwort gaia is the prime example of that.
Needless to say, you should always colonize unique worlds except tomb world. Especially gaias and relic worlds.
Relic world usually comes with planetary features granting +30% bonus to research and some rare material deposits. If I can find such a world, I designate it as a tech world and boost my research. But that’s until I can turn it into an ecumenopolis. Then it becomes an alloy world because ecumenopolis can produce A LOT of alloys.
Planet Size
City and industrial districts are limited only by planet size. So, better find the biggest planet for alloy production. It’s a bit different for other districts.
Number of max districts are determined by planetary features for generator, mining, and agriculture districts. For example, you can find a planet with 40-size, but it can only have 5 mining districts because of the planetary features. Therefore, you should consider max district limits and not the planet size for energy, mineral, and food worlds.
All in all, size isn’t always important!!!
Technology and unity worlds don’t need to be very big. Because they’ll only need 7-8 city districts to unlock all building slots and have enough housing.
There is also a parameter called planet capacity. It’s very simple. Higher planet capacity means faster pop growth. Planet capacity is determined by planet size, housing, undeveloped districts, and general hospitableness. Removing blockers also increase planet capacity.