Location: ~\Xenonauts2\Assets\Assets\xenonauts\template\strategy\construction\building

In this folder you will find all of the files pertaining to building stats.

Example: Power usage

Within these files, you can change things like Storage space, Living space, Radar range, Heal rate from the medbay, etc.

Location: ~\Xenonauts2\Assets\Assets\xenonauts\template\strategy\construction\building:

Example: Increasing the amount of Scientists/Engineers that can be staffed in Labs/Workshops:
Open Workshop.json, advanced, and improved (you need to edit all three, else the upgrades will revert back to the default.) Search for "ManyLinkTemplates":

Below it, you will find 5 instances of this:

You can copy and paste as many of these (remember to select the brackets!) as you want - each one will add one slot to the workshop. Something to keep in mind, the last entry of the original five needs a comma after the last bracket( like this }, )! The LAST entry you make, REMOVE the comma!

The same goes for Laboratory.json, though the line has "laboratory_slot.json" instead of "workshop_slot.json", so be careful when copy/pasting. Something to note: This will update the UI that shows on the base screen, but it will NOT update the tooltip when hovering over the building in the build menu. I haven't figured out where to update that yet.

Location: ~\Xenonauts2\Assets\Assets\xenonauts\template\strategy\masters\projects
Both Engineering and Research contain files we are interested here.

You will find the following section:

Each of these files control the speed at which things are manufactured or researched, based off of what is on the "_max": line. This number contains the number of research/engineering points that are required for anything that is tagged with this duration file (more on this in a second). Obviously, larger numbers = longer time. I do not know the mathematical breakdown of the number, maybe someone else can explain it.

You can do one of two things here: Edit the "_max": in any/each file as you wish, or, do the following:

Location: ~\Xenonauts2\Assets\Assets\xenonauts\template\strategy\projects
Similar to the above location, you will find Engineering and Research folders. Within each is every project that you can do in the game. Warning, there are a LOT of them! What we're specifically looking for here is the first line under "Parent", at the top of the file:
Each project uses one of the duration.json files to control how long it takes to complete. In the above example, you could change that 6 to a 0, and that project would complete much, much faster. Or slower, depending on whether or not you decided to edit the duration.json files!

Location: ~\Xenonauts2\Assets\Assets\xenonauts\template\strategy\masters\actor\combatant\human\xenonauts

File: Scientist_master and Engineer_master.json
and

These two sections control the purchase and monthly expense cost of Engineers and Scientists. Additionally in these files, you will find this:
This, and the Engineer version, control how many points each one generates towards the project time (see above section on controlling project duration). If you don't want to bother changing the duration files/each individual project file, you could just bump this number to make research go faster.

Location: ~\Xenonauts2\Assets\Assets\xenonauts\template\strategy\masters\actor\combatant\human\xenonauts

File: soldier_master.json
Inside this file, you'll find all of the stats and stat ranges for hired/new soldiers. Keep in mind, changing this requires you to start a new game to load the new edits.

Example:

Editing these three lines will modify the minimum and maximum stats a soldier will roll when they show up to get hired. I'm not entirely sure what the middle value does - I've tried changing it to several crazy numbers and left the min/max lines the same, and stats still roll normally.

I have noticed in testing that if you set all three numbers to the same number, the game will STILL occasionally roll a stat or two randomly, so it could be that some other file also has control over stat rolls that I don't currently know about.

Location: ~\Xenonauts2\Assets\Assets\xenonauts\template\groundcombat\item

Within this folder are the folders containing the relevant files for their respective types - e.g. Weapons in Weapons, Armour in Armour, etc. I won't go into details here as the code is mostly self-explanatory. If you don't know what something will change, then don't change it! For weapons you can edit just about everything here - damage, range, armour pierce, etc. If you're really confident in what you're doing, you can even add stats to weapons that don't have them. For example, Armour Pierce or Destruction to weapons that don't typically have them, by copying the code out of another weapon that does.