Stellaris – How to Build a Colossus

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If you are a fan of Stellaris, I can almost guarantee that you are a fan of Star Wars too. Well, what if I told you that you can create a Death Star power-level weapon? All you have to do is learn how to build a Colossus in Stellaris.

The strength to lay waste to an entire planet can be your empire’s. It will take some time, but well worth it for teaching those neighbors a lesson they won’t soon forget.

Recommended Read: What Is the Best Shroud Covenant in Stellaris?

As you can guess, the rest of the galaxy will not be too happy about you creating a weapon of that magnitude. So before learning how to build a Colossus, you should decide if you want to carry the burden of that power.

To build a Colossus in Stellaris, you will first need to unlock the Colossus Project ascension perk. Once unlocked, you will receive a special project to research the Colossus ships. After completing the special project, construction can commence at a Colossal Assembly Yard.


Table of Contents


What Is a Colossus?

Before explaining how to build a Colossus, I should first explain what one of them is.

A Colossus class ship is a special kind of military ship in Stellaris. While most ships are customizable for a specific purpose, Colossi ships only have one function.

That function is to destroy planets. Colossus ships are ginormous and forgo traditional ship weaponry for one super, planet-killing weapon instead.

These weapons can destroy planets in a wide variety of ways, each as catastrophic as the last. Some will blow it to smithereens, Death Star style. Others may flood the planet, drowning its denizens.

Now, acts of planetary genocide are a bad thing, and you would imagine that pacifist empires cannot build Colossi. Well, that is not the case, and pacifists are free to create these weapons of mass destruction as well.

Bear in mind that your pacifist factions and citizens will not be happy about you constructing or using them.

Whether you build one for evil or as a deterrent, this guide will explain the process of how to build a Colossus step by step.


How to Build a Colossus in Stellaris

Building a Colossus is a long-term project, and you won’t be seeing one until the late game, at least.

If getting to the late game is something you are struggling with, I can help with that. I have a guide with a very strong beginner build, published on Gamer Empire.

I made this build to help newer players reach the later stages of the game. It should help you get far enough to build a Colossus.

Building a Colossus takes five easy(ish) steps, and they are as follows:

Step 1: Reach End Game Technology Level

As you can imagine, putting a weapon that is capable of destroying an entire planet into a spaceship is some top-tier sci-fi power.

This is what will take up most of your time when building a Colossus.

You will want to unlock an engineering technology called Titans. This research project will not manifest itself until your empire is very advanced.

Players are not helpless and can speed this process up.

Creating more research buildings, improving scientists, unlocking research buffs, and creating a build optimized for research; are all steps players can take to unlock Titans faster.

Now is a good time to mention something important.

The Titan research project requires the Apocalypse DLC to unlock. If you do not own this DLC, you will not be able to build yourself a colossus.

If you are trying to rush this stage, be careful not to get tunnel vision, concentrating only on research.

It takes a lot to run an empire, and while research is one of the most important parts, you should take care not to neglect other facets of your empire.

When you do unlock the Titan research project, you are ready to move on to the next stage.

Step 2: Unlock the Colossus Project Ascension Perk

With your technology level now being the envy of the galaxy, your empire stands ready to create a weapon that will make your foes quake.

On your way to getting this far, you have likely unlocked quite a few ascension perks. To advance, you are going to need one more, the Colossus Project perk.

Throughout a game of Stellaris, you are only ever allowed eight ascension perks.

As the game goes on, your time between perks becomes greater as the unity cost for traditions becomes higher.

Depending on your unity production and how many traditions you have already unlocked, you could be in for a long wait here at stage two. I do have a couple of tips to speed this step up.

First, you probably have known for a while that you want to build a Colossus, so plan early.

When you think you are getting close to late-game tech, save your next ascension perk. Then as soon as you unlock Titans, you can unlock it straight away, in a few short clicks.

Second is to not soft lock yourself out of the Colossus project perk by unlocking all your traditions too fast. I have done this as a spiritualist empire before.

I wanted to build a colossus but used up all of my ascension perks before I even unlocked titan tech. Locking myself out from ever being able to build one.

After you unlock the perk, it is time for stage three.

Step 3: Research the Special Project

With the perk unlocked, there are only a few more hoops to jump through before construction work can begin in earnest.

A new special project will appear in your situation log. You will have to pause work on your engineering research while this special project is underway.

About halfway through the special project, you will receive an in-game prompt. This is to select the first planet killer weapon you wish to unlock.

The weapons offered to you will depend on your ethics. For example, pacifists cannot build world cracker Colossi.

Upon completion of this special project, every player will get a pop-up informing them of your empire’s capability of creating planet-killer weapons.

With all the boring science out of the way, the next phase is building your glorious new super weapon.

Step 4: Building a Colossal Shipyard

A project of this size requires a dedicated construction area. Now, you may already have one of these constructed if you have access to the Juggernaut or Star Eater technologies. For now, I will assume that you don’t.

Colossal Assembly yards are buildings built on top-tier starbases, also known as Citadels. Another requirement is that the citadel must have at least one Shipyard module installed.

At this stage of the game, chances are high that you already have a citadel with shipyards installed.

Building the assembly yard there will save you a lot of time compared to upgrading a base to the top tier.

If your building slots are full on your citadel, you can replace one of the buildings with a colossal assembly yard.

The installation work will take some time, but while you wait, you can tweak your Colossus designs in the ship designer menu.

At this stage, you may start receiving new research projects for different colossus weapons.

Step 5: Building the Colossus

Finally! After years of in-game time, you are ready to build your Colossus. However, I am afraid there is one more piece of bad news. The construction work for one of these will take a long time.

Select the citadel where you built the Colossus Assembly Yard, and queue up the construction of your first Colossus.

While you wait, you could start finding some nice targets to aim for. Perhaps a fallen empire that bullied you or a rival who insulted you at the beginning of the game.

When construction finishes, you are now the proud owner of a planet-destroying super weapon. Congratulations, you now know how to build a Colossus in Stellaris.


What Owning a Colossus Means for Your Empire

Having the know-how to build a colossus is only one part of being a responsible weapon of mass destruction owner.

Owning a Colossus will change the game a little bit and how other empires interact with you.

For starters, a lot of empires will be wary of you, and probably for good reason.

Every empire will also receive a total war Casus Belli against you, called Stop Colossus. On the bright side, you also get a Casus Belli on all of them too.

These total wars can only end one of two ways, a status quo or the destruction of one side.

Empires that are more powerful than you will not hesitate to sweep in and attack you, Colossus or not.

Using the weapon on another empire will make them hate you, and other empires will become further cautious of you.

Some may hate what you are doing and may form alliances to orchestrate your destruction.

Lastly, using the weapon makes the target more militant isolationist and will cause their war exhaustion to skyrocket. A tactical use of the Colossus could help bring wars to a swift yet bloody end.


This is everything you need to know about how to build a Colossus in Stellaris.

If you have any questions or suggestions for this guide, please let us know in the comments section below. As always, have fun unleashing your super weapons in Stellaris.

Simon Neve

Simon lives in Northern Ireland with his wife and two children. When not caring for his family, Simon enjoys video games, board games, and tabletop roleplaying games. When playing isn't an option he writes about them instead.

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