Played through a game on launch day on had a blast - sorry, I know I wasn't supposed to yet. I see plenty of people posting plenty of feedback on the gameplay and I don't have much to say on the matter that's different, I just want to wait and see where that goes.

However, I couldn't resist the urge to dig into the files and get a first impression on what modding this game is going to be like.

Initial impressions are definitely positive. This really is a cursory glance, of course, but I'm happy with what I've seen. I even made my first mod! Not sure how into detail I should be going at this point because I know Alpha is not really intended for this so I don't know if I should be encouraging people to play with this and won't be providing instructions just yet. But I will show proof that I've done it, and I'll share some feedback on how it is right now, and then I'll shut up until Stardock gives me the okay to keep playing around.

WARNING: MODIFYING GAME FILES MAY HAVE UNINTENDED CONSEQUENCES. STARDOCK AND MYSELF ARE NOT RESPONSIBLE IF ANYTHING BREAKS AS A RESULT OF EXPERIMENTATION, AND THEREFORE DOING SUCH IS DISCOURAGED AT THIS POINT IN TIME*

*ProbablyDefinitely, as confirmed by Kryo below

That said, also remember to make a backup if you do go experimenting. It'd suck to have to redownload the whole game.

I went with something that is both interesting to me as a modder and easy to evaluate - Nebulas. Dug around the files for a bit and figured I could change parameters to do what I want. So my first step was to make a Mods folder. I tried this because I saw the options menu had an 'enable mods' button. I then made a sub-folder called 'NebTest' and took a stab at what I thought a mod structure might need to look like. That, uh... didn't pan out (nothing breaking, it just didn't do anything). 

After just one failed attempt I got antsy and decided to cut to the chase - by just modifying the raw file. So I made a copy of the file (appending BAK to it) and then modified the original.

Turns out the way it works (for now at least) is that all files in that folder are included. I was, however, greeted with a clear error message on launch explaining that I had duplicates and it immediately became clear that I should be putting backups into a separate folder. I moved it into my now-unused mod folder and started it up again.

The Nebula effects are defined as 'Multiplier' or 'Flat' at the moment, but this appears to be broken. For example, sensor range is defined as a multiplier of -0.50. That result would be negative, and negative range doesn't seem like a good idea, but in my first test I figured I'd see if maybe they were using the magnitude of the range (it seemed strange to me so I wanted to verify). Sure enough, it seems like the 'Multiplier' is additive, as changing the value from -0.50 to 0.50 increased the base range.

Of course, it began bugging me at this point that the nebula still claimed to be reducing range. I added some more modifications to the effect (I decided I wanted to adjust MoveCost of nebula tiles so you move faster in Nebulas, just for kicks), and dug around in the files until I could find the Nebula description. I created a new description, updated the Nebula to point to that description, and loaded it up again.

This test verified the non-intuitive nature of 'Multiplier' effect types. Multiplying 'MoveCost' by 0.50 had no (clear) effect (given the truncation of moves remaining, it's possible that I didn't notice that my ship was being slowed down - it should have been moving 2/3 as far). But when I tested it a second time with the factor -0.50 I got exactly what I wanted - double movement speed! (Of course, default cost is 1.) This seems to me like it's an additive effect instead.

Without further delay, pics or GTFrakO, right?

Imgur album is here: http://imgur.com/a/1Y2WO

Overall:

• XML follows specific schema and has a tool which validates this on launch - should be very nice for modders as it both defines distinct limits and enforces good syntax. Presumably the tool could eventually be made available without launching as well - frequent validation is nice.
• Modifiers have BonusTypes which can be (at the very least) "Multiplier" or "Flat". "Multiplier" type seems to work incorrectly or, at the very least, unintuitively. But hey, it's an alpha!"Multiplier" works a little bit unintuitively, but having thought about it more I think what it means is that you add the value to the multiplier. The end value of the bonus item should be calculated something like (base + (sum of all Flat Bonuses)) * (1 + (sum of all Multiplier Bonuses)), or perhaps (base * (1 + (sum of all Multiplier Bonuses))) + (sum of all Flat Bonuses).
• Modding is still pretty easy to get into and looks like it should be far more capable than in GalCiv 2 - which is saying a lot!