So, let's begin.

As you might have already noticed, WildCard loves consuming your PC space. So they released a game with all its DLCs for a size of 400 GB. Quite huge, I agree. But we are not stupid people. There is an easy way to reduce a game size without deleting it :D.

Reducing size without downloading extra software is nearly impossible (Of course, you can delete the game, but we are here to be smart).

The needed software for us is Compact Gui.

To download it, you need to jump to the GitHub website.
A link is here: https://github.com/IridiumIO/CompactGUI.


If you don't trust links in steam guides, you can do it another way.
Just google Compact Gui in your web browser, and you will receive a link to GitHub.

 
 
Ok, once we are there, the next step is downloading it.

 
Scroll down the page until you get the button 'DOWNLOADS'.


Once you are on the downloads page, you will see various versions of this software. I recommend downloading the latest one, but it's for you to decide.

If you are smart and know how to use GitHub, download CompactGui.exe.

If you don't know how to use it, scroll down until you see Assets, and press CompactGui.exe. It will start the downloading.


Install it, and let's move. If you were able to download steam to see this guide, I hope it is not a problem to download CompactGui.

If the installer asks to download Microsoft .NET, then it's okay and download it. Those are system files which are extra to download for software developers.

If you have read so far, then you were able to download it successfully.

Once you open Compact Gui, you will see this.



To be fair, there are not many buttons here to decide which to press.

The gear button, as you may already realise, is settings. However, there aren`t many settings for you, and for regular users, you don't need to change anything.

The needed button for us is 'Select Target Folder'. Press it, and the selector will open.

You need to find where your game is placed. Usually, it is this pass.



Once you are there, press 'Select Folder'.

You will receive this.
(As I already compressed my game, then my menu is a bit different, but I will show you the example of GTA 5)
(On the right side is my menu, it shows how my game was compressed and did I want to uncompress it, yeah, I didn`t install all DLCs at the moment of writing this guide, so I just compressed the raw game. However, you can still see the result that it reduced almost 50% of the size)

Press 'Compress' and let's move.


 
Here you will see different options to choose from before compressing.
First is compression mode - You can select how fast the process would go, but the size is also affected.
XPRESS4k - the fastest but reduces the smallest amount.
XPRESS8k - slower but reduces size.
XPRESS16k - the best one for this game - reduces the most space but consumes much more time.
Also, you can see LZX mode - it is the next stage of compressing, but for this game, it will compress the same as XPRESS16k but consume more time.
Then you can see 'Skip poorly compressed filetypes' - this option will skip files that don`t reduce much after compressing. It saves time, but you should turn off this for the best result.
One more button, 'Skip user-submitted filetypes' - this feature is new for this software, and I wouldn`t recommend using it, but what it is doing is skipping compression of files, which other users said it is not necessary to compress. I haven`t checked this feature with ARK, so I don't know if it will affect the result of compression. So you can use it only if you are brave.
The last button is 'Watch folder for changes' - I don`t know how exactly it works. But it doesn`t affect anything. So as the golden rule says, if you don`t want to make mistakes, don`t do them. So turn off this feature, and let's move to compressing.

Press compress, and it will start the process.


 
After the process is finished, you will receive the reduced by-size ARK.

(As I said before, in this guide, I did it on the example of another game, but you can still see my ark results back).

The finished process would look like this.

 
For those who, after all these steps, still don`t know what they have done. You can press 'Uncompress', which will remove everything you have done.

As my guide already has shown, this way is working. Compressing a game doesn`t affect any game mechanics, and the game works stable. This method works with almost all games; you can check on the GitHub page the results of compressing in other games.
I hope my guide was helpful for those who had some questions while reading other guides. Feel free to ask me if you need any help. I will try to help you.
For those wondering how to close the app, open the task manager and shut it there (I also had this problem :D)

Чтож, гайда на русский не будет, берите гугл переводчик и переводите, там вполне можно всё понять и по картинкам который я приложил. Удачи в использовании.