Introduction

Modding is important to many games, but it’s an integral part of Sins of a Solar Empire II. From small private mods to total conversions set in most popular sci-fi settings [insert your preferred sci-fi universe].

You name it, Sins of a Solar Empire: Rebellion had a mod for it. Sins II was developed with the intention of empowering modders to realize their creative aspirations, drawing from extensive experience in the field. This guide cannot cover all the details of modding but will walk you through the most relevant steps.

Map Creator Guide

Many of you might have opened this guide, to learn how to mod your own unique map. For that we have written a dedicated guide here:

https://wiki.sinsofasolarempire2.com/space/SSEFW/2222784519/Map+Creator+Guide+-+Solar+Forge

First Rule of Modding

Sometimes you just want a tiny local mod. Maybe you want to give some extra health to a titan, or make a scout go light speed in normal space just for fun. The most convenient way would be to simply edit the game files directly in the game files directory.

HOWEVER, the first rule prohibits you from modding in the game file directory. There are a multitude of downsides for what seems an easy workaround at first. For one, you could corrupt your game files and accidently cause issues, which will require a full reinstallation. For another, all your work will end up lost if a patch is released, as it will overwrite any local changes.

For this reason, you should always work in a proper mod folder.

Your Workspace

So where should you work?

The best place to create your mod folder would be here: C:\Users\[USERNAME]\AppData\Local\sins2\mods

This will allow you to use your mod locally and quickly check any changes. If you want to share your mod with a small group of friends, you could send them the files manually, and they would install the mod to the same path.

If you have plans on making your mod available to the broader public, you will have to create a Mod.io account. We have covered how to upload mods in our map creator guide highlighted above.

Your Vision

If you opened this guide, it means you already had some ideas on what you want to create. We need to structure your vision into difficulty categories and work through the tasks appropriately.

The easiest tasks would be to simply change some unit stats. E.g. Increase speed of a ship, decrease cooldown of a weapon, etc.

Medium tasks include creating new abilities or creating new game mechanics. Creating new game mechanics will mostly revolve around being creative with the existing mechanics, because you cannot code changes into the game engine. However, a combination of several game mechanics can create a new, unique one.

The hardest tasks include creating new ship models. This guide won’t be able to cover that topic, due to the depth of such an endeavor. If you have no experience with tools like Blender, you either must have immense motivation for your mod, or find some mod team members with the required skill sets.

First Steps – Modifying Game Files

We will take a small step and start with the easiest task. Let’s give TEC Cobalt frigates a weapon they deserve – medium autocannons with 1000 damage per second.

For this we need to create a folder: FirstMod.

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We will also want to create a file called .mod_meta_data with simple content:

You can create one with any text editor. This is required for the game to run our mod later.

Now go to your Steam library, right click on Sins 2 and select “browse local files”

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This will open the folder with the game files. We want to find the file where weapon stats for the Cobalt are stored. All such files are stored in the folder entities. The folder will have several thousand elements, checking out every individual one would be unrealistic, but let’s try the search function.

TEC game files begin with trader_ and Cobalt ships are usually called by their class. Since Cobalt frigate is a “light frigate”, the name will be akin to trader_light_frigate. Once we begin entering the file name, we will actually find 3 files:

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We wanted to adjust the Cobalt’s weapon, so it would be logical to go directly to the file which is called _medium_autocannon. However, since we are learning how to mod, let’s check out the Cobalt file first.

You can open these files with any text editor. The author of this guide uses mostly Notepad++, but you could also use something like Visual Studio Code if you want more tools.

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The Cobalt file uses JSON format and has 200 lines, which may be hard to read for a beginner. Feel free to explore the file, but do not be afraid if you don’t understand it, as you will explore various functions with time.  What helps with understanding of the game files is the “indentation” – how much specific text is pushed to the right.

In the screenshot above, we see that the words version, spatial, physics, and hyperspace have less indentation (are closer to the left side of the document), than other text. The indentation indicates categories. Those categories help us understand the function of embedded values. E.g., in hyperspace we have speed: 215000.0. This indicates that the hyperspace speed of the vessel is 215,000 kps.

But let’s stay focused. For now, we need to find info on a weapon. We will use the search function again, and search for “weapon.”

Our first hit is not perfect, as we get some AI logic for the weapon, which can be easily indicated by its indentation. Let’s continue our search.

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Our next hit is luckier, we hit the weapons section and can check out the individual weapons of the vessel. In our case, the Cobalt has a single trader_light_frigate_medium_autocannon.

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This is also the name of the file we need. Now we can return to our entities directory. We could search for the weapon with the name, but we already have it in the list.

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A common beginner's mistake would be to open the file here. We call it a mistake because if you open it here, you are likely to begin editing the values in this file, instead of editing a copy in your mod folder. This may not happen to you while you have a single modded file but will most definitely happen as your mod grows.

For this reason, we need to grow a habit of copying files of interest. Let’s copy it into our FirstMod folder.

Wait! We cannot simply copy a file into the mod folder! We have to follow the same directory structure as the base game. Since our weapon file comes from the entities folder, we need to create one in our mod folder as well.

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Now we can safely open the file. It’s actually smaller than the Cobalt light frigate and fits on a single screen.

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Most values are self-explanatory. Since we are keeping this section simple, let’s focus on adjusting the damage per second. As you can see, there is no keyword “damage per second.” There is damage, and there is cooldown_duration – where the first value determines the damage per shot, and second value determines how fast the weapon reloads.

To get 1000 damage per second, we will set the cooldown_duration to 3 seconds and damage to 3000.

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Controlling Mod Progress

It’s good practice to check if your mod works as intended every now and again. While you are a beginner, it’s best to check it even after tiny changes to avoid searching bugs in the entire mod structure.

To test, we can simply start our game and navigate to Mod.io, where we will enable our mod by hitting the plus sign, and then “Apply Changes”:

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Once the mod is enabled, just start a normal game. Since we wanted to increase the Cobalt’s damage per second value, we will start as TEC.

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Once our Cobalt is built, we can actually see its DPS as 1150. That’s because I have picked TEC Primacy and I get the 15% damage buff while close to my homeworld.

With 3000 damage (or in our case even 3450 damage) per shot, our Cobalt will pretty much one shot any frigate.

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Unexpected Issues

Modding often brings unexpected surprises. In our example above, we wanted to give the TEC an edge in combat by buffing the light frigates. However, we did not account that militia also use TEC ships. Meaning, while we did buff TEC, we accidently impacted the neutral militia mechanics too.

This experience also highlights why it’s important to check on your mod progress. You may do everything right and avoid all the bugs from the get-go. But you can still get unexpected game changes because of how mechanics are related to each other.

How should you approach such challenges? Well, every challenge is different and requires you to be creative. In the particular case of the Cobalt frigate - assuming you do not have modding resources to create a completely new ship - we could create a duplicate of a Cobalt frigate and split them between TEC and neutrals.

Medium Difficult Tasks

Let’s continue with our example. We want to change the militia’s Cobalt so that it keeps its old stats.

As described above, we will create a new Cobalt type which will appear identical in the game, except for its weapon damage. This new Cobalt type will use a new weapon type with increased damage; and the new Cobalt type would then be used by… no, not militia. We will actually give the new Cobalt to TEC players and keep the old Cobalt for militia. The reason for this is that the Cobalt is being used not just by militia, but also by minor factions, events, etc. If we change the TEC Cobalt to be the new one, we only need to keep track of TEC files, and not all the various neutrals and minor factions.

Since we want to create a new ship and a new weapon, we will need 2 files which document all the ships and weapons. The first is called unit.entity_manifest, and the second is called weapon.entity_manifest.

You can easily find these in the original game folder by searching for “manifest.” Copy these files into your mod folder, inside the entities directory. Furthermore, since we want to adjust ships built by TEC factions, we will need the files for TEC Enclave and Primacy. You can find them by searching for “player” and copying trader_rebel and trader_loyalist.

We will also want to copy the Cobalt file, in addition to the already copied weapon file. Once those 2 are in our mod directory, we will rename them, by adding “2” at the end of the file, for simple identification that it’s an identical file with minor changes.

After all the steps are done, your entities folder should look like this:

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We will start by editing the manifest files.

As our mod is rather simple at this stage, we will add the new Cobalt into the manifest and remove any other entries in the unit.entity_manifest.

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It looks very similar for the weapon.entity_manifest:

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Now in the player files, both “rebel” and “loyalist” we want to edit the buildable ships. The easiest way is to search for trader_light_frigate and replace it with trader_light_frigate2.

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Finally, we need to adjust our new Cobalt to use the new weapon. Inside the new Cobalt file, search for the weapon just as we did it before, and edit the name of the weapon file to correspond with the new weapon.

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We do not need to adjust the weapon file, beyond renaming it to trader_light_frigate_medium_autocannon2 because it already includes all the changes from before.

Now we can start the game and check the stats of the ships.

We will see that our own Cobalt has the increased damage value.

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While neutral Cobalts have the vanilla game stats.

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Congratulations, you have tackled a medium task!

Where to Continue?

Once you learn how to change stats, you will likely want to adjust abilities. An incredibly important know-how is to learn to read the structure of game files. You can expect the naming to be self-explanatory, however some naming conventions are not identical to those in the game.

For example, if you wanted to adjust the Kol’s ability roster, you would not find any file named “Kol.” That’s because naming is done on a more meta level. Kol is a battleship class. It’s also a TEC ship.

We learned that TEC is replaced with “trader_” in the game files. If we were to search for “trader_battle”, we would find Kol files as trader_battle_capital_ship. Now, if you were to open the Kol file and search for “abilities,” you would find the list of Kol abilities:

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With this finding, you’d know the ability names and would be able to adjust them or completely replace them with new ones. But remember, if you create a new ability, you MUST add it to a manifest. In this case, add it into an ability manifest of your mod.

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Failsafe

Even though we have highlighted the importance of structuring the game files, Sins II has a very good in-built failsafe which provides you with info whenever something breaks down.

For example, if you were to forget to add the new Cobalt into the ship manifest, you would get an Alert message indicating what the issue could be. In the screenshot below, we can see that a unit_definition has been not found, hence we need to make sure that our new Cobalt is in the unit manifest file.

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Special Effects – Solar Forge

Once you master editing the game files, you will likely want to work on special effects for your abilities and weapons. This is much easier than creating a fully-fledged new ship, and therefore falls into medium tasks, albeit the harder parts of it.

To create new effects you will need “Solar Forge.” It’s an internal Sins tool which allows you to create maps, but also to create various special effects.

We have already described the installation process in our maps guide, so make sure to check it out: https://wiki.sinsofasolarempire2.com/space/SSEFW/2222784519/Map+Creator+Guide+-+Solar+Forge

Particle effects in Solar Forge could take an entire independent guide, so we cannot handle it here. However, if you are interested in creating custom weapon/particle effects, it’s always easiest to start by studying the existing ones. Just navigate to the effects folder of the base game here: C:\Program Files (x86)\Steam\steamapps\common\Sins2\effects

Pick any effect of your liking. We have picked the Orgrov’s torpedo impact effect, and here is what it looks like:

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Now you can study the structure of the file and play around with its properties.

For example, if we were to change the “core” color to red, this would change how the effect looks:

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Such a minor change, but the effect no longer looks like an explosion, and more like some kind of debuff, which could be used for a new custom ability!

Conclusion

Modding is not just fun when you see the result, but as a process. Be creative, let your ideas manifest and share it with our community!

We have covered some important milestones in this guide, but there is still a lot to be discovered. Experiment with your adjustments, gather experience, and become even more creative!

Should you ever stumble on an issue you cannot overcome yourself, make sure to check out our official Discord server, and ask other community members for help. Chances are, they already have an answer for you.