The first thing you need to do is create a new folder for the mod. Like this:


Note that the mod name must end with .rte, you know, like ZombieNinjaCorporation.rte, or Robots.rte. If you remove .rte or add anything after it, like I do with .off, you'll have the mod disabled, which is handy if you don't want to have the mod on now, or it refuses to work for you and you don't feel like repairing or updating it right now.

Next thing you have to do is take Index.ini and ModuleIcon.bmp out of any other faction's base folder. You know, Ronins, Techion, Imperatus - it doesn't really matter. Copy them and paste inside of your .rte folder.

Feel free to edit the logo, you can freely do that with MS Paint or whatever raster editor you got out there. It doesn't matter, as long as it can save as .bmp and you stick to this palette when picking colours:

I'll return to it later, for now we got index.ini to edit. All we need to do is learn how to edit file paths.

Index.ini looks someway like this:

Now, we're going to change it to look like this:
Note that [ and ] are unnecesseary and just indicate you are free to write anything you want there or have to write down something specific depending on file location/mod name. And the // before the line simply disables it, seeing as we don't have any other documents in the mod for game to read. But don't worry, that'll change soon! Also, another important thing - try not to mess up the formating, it is important.

If you have tryed launching the game already and it doesn't crash, good job, your first mod's foundations are perfectly intact!
Now, we'll move on to adding actual content to the mod, and learn about dependenencies on the way there. Note that taking and reusing the vanilla (slang for unmodded content) game data when creating objects is a simple way of creating something functional quickly, and taking someone's else mod content without permission and with intention to upload it is a jerk way. And that's bad, m'kay?


Anyways, back to business! Now, I'll take these files and move their copies into my folder:
Ronin.rte/Devices/Weapons/AK-47.ini
Ronin.rte/Devices/Sprites/AK47000.bmp
Ronin.rte/Devices/Sprites/AK47001.bmp
Ronin.rte/Devices/Sprites/MagazineAK47.bmp

Done!
You can try using another weapon too, but note that all weapons have different dependencies and may require different files, not to mention it might make it harder to follow this tutorial, so you can leave that for dessert.

By the way, feel free to rename the sprites (term for, you know, the images 2D game uses) - as long as file path you'll use refers to the proper thing. Also, about AK47000 and AK47001 - these are considered different animation frames of same sprite. You can have just one, or two, or over nine thousand frames for your gun if you feel like it, just don't forget to have the 000 numeration thing if there's over 1 frame, and remember to define amount of frames in data (More about that later).

Now, open up the previously created index.ini and change

//IncludeFile = [Your Mod Folder Name].rte/[Something].ini
into

IncludeFile = [Your Mod Folder Name].rte/[AK-47 or whatever you named the thing].ini

Yes, remove //, uncommenting is very important.
Next, open up the weapon .ini, and we'll change the file paths. Simply scroll down or use search function to find lines like Ronin.rte/Devices/Sprites/AK47.bmp and replace them with new ones, for instance TlenoTutorialGun.rte.rte/MagazineAK47.bmp. If you feel unsure whether it all went fine, just launch the game - if something is wrong, the game will politely (If you can consider crashes polite) inform you on which line of which file it failed to load. Once all paths are altered (there should be just two for AK47 - for the weapon itself and the magazine) we can move on to replacing object names to avoid game confusing original weapon's and new one's objects.


Firstly just find find all instances naming the bullet, like Bullet AK-47 and replace them with something new like Bullet TlenoTutorial. Afterwards you need to do the same with Ak-47's (People who are modding a different gun, you might need to look into the .ini on your own to see what needs replacing, generally you need to replace all names of all new objects with new ones, same with mentions of those objects within objects under them - it's best to use Replace function for that, just try to replace the exact term, like Bullet AK-47 instead of just Bullet) Tracer, Round, Magazine and finally you ought to rename the gun itself. Done, now we can move on towards altering the weapon properties!

Now, before we move on to making infinite ammo galing speed superlight AK47 that shoots artilery shells or whatever, you might want to actually, you know, change the visuals. As already mentioned, any basic raster editor is perfectly fine, even MS paint, simply because instead of requiring any sort of transparency in the images the game ignores this super bright pink you might have noticed already.
Anyways, open up the gun image, open up this little fella found in game's Base.rte folder to have the palette to take colours from, and draw, draw!
Here, take a gander at what I scooped up in five minutes for the example gun:


I'm leaving the magazine, which is in a separate file, unedited, but nothing stops you from altering it the same way you altetred the gun. Actually, I mind sound abit like captain obvious, but you can do that with all images.

Now, let's return to the weapon's .ini again. I shall, now, explain what which of those separate game objects does and what values you can alter to make the thing work different. Once again, watch the formating!





In case something else is unclear, feel free to ask about it in the comments!

A large list of useful links and tutorials on Starbound Fan Forums, by Seraph[forums.datarealms.com]


Some more notable tutorials:

• Creating first actor by dragonxp[forums.datarealms.com]
  
• More in-depth look at what each statement does, by Major[forums.datarealms.com]
  
• An extremely helpful pixelart tutorial by CrazyMLC[forums.datarealms.com]
  
• CaveCricket48's .lua scripting tutorial[forums.datarealms.com]