I've been testing and exploring the mod tools available for Final Liberation and want to share what I've learned. Within some very specific constraints, it's actually pretty easy to mod the game in certain ways, and I'm hoping to share what I've learned and hopefully hear what you've learned as well. I would love for this thread to become the start of a modding community on GOG.com, but we'll see what happens.

I am going to start the thread off with a number of how-tos that I've learned, and I intend to update this first post with links to mine and others' posts as we go along. Let's get modding!

TABLE OF CONTENTS

Getting started
Creating a new unit and detachment
Creating a new map (not started)
Creating a new company (not started/unknown)
Creating a new faction (not started/unknown)
Creating a new campaign (not started/unknown)

GETTING STARTED

Essential modding tools and resources
The HPP files, TXT files, and utilities listed here can all be gathered from the Final Liberation Editor.zip and Tools16.zip resources available in the Yahoo Group mentioned below. I'm not going to go into great detail here as to what each of these files and utilities do. For now, just know that to mod the game, you'll need most if not all of them.

The old Yahoo groups
To start, you're going to need to get some files, and the best place I know to get them is on the old Yahoo groups. There are two Final Liberation Yahoo groups. The only one that appears to still be active (i.e. the only one that accepted my request to join) is this one: https://groups.yahoo.com/neo/groups/finallib/info. Once you get in, head to the Tools folder and download and extract "Final Liberation Editor.zip" and "Tools16.zip".

HPP files
The HPP files are essential when creating new objects for the game. While there doesn't at first appear to be much going on in these files, the HPP files are where your items must be first defined. If you want it in the game, it needs to be created here first.
- CHASSIS.HPP
- CID.HPP
- DETFLG.HPP
- ICONS.HPP
- UNITS.HPP
- WEAPON.HPP

TXT files
These TXT files are where you fill out the details of your units.
- SUPPORT.TXT
- UNIT.TXT
- WEAPON.TXT

UTILITIES
- WEAP2DAT.EXE
- SUP2DAT.EXE
- UNIT2DAT.EXE
- TOOLS16.EXE
- UNRES.EXE

A directory with all the game's SETxxxx.BIN files
When creating new units, it's best to recycle another, similar unit's action set. More detailed instruction will follow, but first you need to extract the game's SET files.

1. Create a folder somewhere in your game directory and copy UNRES.EXE and SET.MUK into it
2. Open a Command Prompt window on your computer and change directory to this folder
3. Type "unres set.muk set.lst" and press enter

All the SET BINs will be extracted to your folder, and you can now copy the ones you want to add to the game-dir\set folder (as will be discussed when we get to the new unit creation guide).

Backup directories
Before you start messing with the game's files at all, make sure you back up at least the DAT folder in the game directory! Screwing up the files in this folder can make your game unplayable, so make sure you regularly backup not only the original DAT folder, but also any copies of the DAT folder that contain working versions of your mod.

If you're going to modify any existing units graphics or action sets, you may want to backup a few other directories, but I'll assume that if you know how to do that, you know which folders to backup and how.

A TGA editor
I personally haven't gotten this far yet, but apparently when/if you want to create new graphics for your unit, you need to create a TGA image that will be compiled into a new CEL file.

Notepad++
Personally, I find Notepad++ extremely useful when creating, editing, and modifying units. The good old standard Notepad application works too, but Notepad++ has tabs, great search capabilities, and will save and restore your tabs when you close and open the application.

A Win 95/98 virtual machine?
I have not had much success with tools16.exe yet, and I've begun wondering if I should spin up my old Windows 98 VM. We'll see...

Back in the days, I've been looking into this Yahoo! Group too: It's called "Final_Liberation"

They have files here that may or may not work, such as Legions of the Volistad (Ork Vs Ork, Imperium Vs Imperium), 2 chaos mods, maps, editing tools and a few other stuff.

It may help the FL modders to know there's another group that may contain repositories of tools and mods to look into.

Yeah, IrfanView failed utterly in showing the CEL file. Since then I've learned a little more about CELs and I'm pretty sure they're a one-way street. TGA to CEL, and there's no way to go back again.

Which makes it really good that we have the three TGA examples that we have... Unfortunately no Titan TGAs, though.

You can extract sprites sheets (sort off) with tools16, I was playing with the Leman russ tanks the other day. However it's still importing them that's the problem. Seemed a auto desk program from the mid 90's was one way used alot to create cel's, ill dig some more. Just been accepted on the yahoo group so will ask some questions

CREATING A NEW UNIT AND DETACHMENT

Creating a new unit in UNIT.DAT
In modding terms, "unit" actually refers to two separate but related things. A "unit" is the single graphical sprite, defined in UNITS.HPP, that represents a single body on the game field. Whether that body be a tank, a titan, or an individual soldier, they are all represented by a collection of files that together constitute a sprite. A "unit" is also the collection of 1-5 of these sprites into a single, commandable game unit. For example, you might create a new unit (game unit) called "Space Marine Devastators" that consists of 5 units (sprites or infantry models) of Space Marine Devastator. That's totally confusing, I know, but it's important to understand that the game sometimes uses the word unit to refer to a game unit and sometimes to a sprite. I will henceforth refer to graphical representations of bodies as "sprites" and collections of 1 or more sprites as "units" for clarity, but I wanted to make the point first.

The individual sprite is defined in these files: UNITS.HPP (which defines the "xxxx" number to be used in the following directories), SETxxxx.BIN, PAGExxxx.CEL, UNITxxxx.TGA, and UNITxxxx.TXT.

STEPS:
1.UPDATE UNITS.HPP -- Open UNITS.HPP and add a new UID and corresponding four digit number. The UID will be filled out in UNITS.TXT and used in SUPPORT.TXT, and the four digit number will be used as you make the various sprite files. Make sure both are unique, and spend a little time studying the other numbers in the file to figure out what an appropriate number would be for your unit. For example, Ork units are in the 3000 range, so it wouldn't do to make a Mega Nobz unit and assign the number 1050 to it.
2. CREATE AN ACTION SET FILE -- Go to the directory where you extracted all the SET.BIN files previously (see Getting Started>Essential modding tools and resources), copy the SETxxxx.BIN file of a similar unit to your new unit, paste it into game-dir\set, and change the number to the four digit number.
3. CREATE A CEL FILE -- Go to game-dir\cel, copy the PAGExxxx.CEL file of the unit from step 2, and change the number to the four digit number
4. CREATE THE PEDIA FILES -- Go to game-dir\pedia, copy the UNITxxxx.TGA and UNITxxxx.TXT files of the unit from step 2, and change the number to the four digit number
5. UPDATE UNITS.TXT -- Create new entry in UNITS.TXT and make sure the UID is the new one from the UNITS.HPP file. Modify the new entry as needed. (There is a lot going on here, so I will be putting additional instructions for this part in a later post.)
6. GENERATE A NEW UNIT.DAT -- Open a Command Prompt window on your computer and change directory to the folder you're storing your dev files in. Type "unit2dat unit" and press enter.

At this point, your UNIT.DAT file is ready to import into your game directory, but you won't be able to deploy any of these units in a game until you create a detachment that uses the unit. To do that, you will need to modify the SUPPORT.DAT file.

Creating a new detachment in SUPPORT.DAT
If you actually want to use your new unit in a game, you have to put it in a detachment. These are the things in the campaign that you add to those four empty boxes in the army screen. A detachment consists of one or more units, usually of the same kind, but not always.

STEPS:
1. UPDATE CID.HPP -- Just like with UNITS.HPP and creating units, this is where your new detachment will first be defined. Again, study the existing IDs to make sure that you're choosing unique values and appropriate numbers.
2. UPDATE SUPPORT.TXT -- Just like with UNITS.TXT, this is where you fill out the details of your new detachment. More instructions for modifying this are required, but for now, just copy a detachment that's similar to the one you want to build and update the CID(s), UIDs, and text values.
3. GENERATE A NEW SUPPORT.DAT -- Open a Command Prompt window on your computer and change directory to the folder you're storing your dev files in. Type "sup2dat support" and press enter.

Replacing the game's DAT files
Assuming you didn't create or modify any weapons used by your units, you're now ready to add your files to the game and try them out!

STEPS:
1. BACKUP THE DAT FOLDER -- You're going to be replacing very important files, so make sure you backup anything you don't want to lose. I personally have four different DAT folders. One called DAT which is of course required for the game, one called DAT-DEV where I store all the development work I'm doing, one called DAT-GAME which stores the mod that I'm using for my game, and one called DAT-ORIG which is a backup of the original state of the DAT folder.
2. COPY THE .DAT FILES -- When you're ready to try your mod out, just copy the UNIT.DAT and SUPPORT.DAT files you just created into the DAT folder.
3. TEST YOUR FINAL LIBERATION MOD -- Load up FL, then the quickest way to test your new unit is to start a Quick Battle and try to add the new detachment to your army.

Good luck!

I would love to see your recommendations on modifying the TGAs. I'd like to create some new infantry sprites, and the work ahead modifying each of over 100 cells is daunting...

Do you know how the game decides if weapons fire together? I'm trying to make it so the Leviathan's lascannons fire seperately from it's tank bolters (they're kind of wasted together--the bolters won't bother heavily armored units, and if it's firing at infantry it's got more than enough bolters to splat them without wasting the lascannon fire).

Have there even been mods released for this? The modding tools have been out for quite some time, but i wasn't able to find anything.

There was a semi-complete Chaos faction mod, I think a copy of it has already been posted somewhere in here. No other mods that I know of.

Ignore this post. Solved the issue myself.

Is there a way to add a new detachment to the campaign?
If so, how does the game check the unlock conditions?

Hi all so if you can find it does the chaos mod actually work?

Hi,

Thanks FerociousBeast for the infos.

Does anyone know what "hitoffsetx" (armor values) and "xoffset" (weapon values) mean ? Both are in the unit.txt file.

Hi,
I looked into this, and after a short while intensely staring at the text editor, I came to a conclusion:
They look like values for determining how far the off the shot came from.