[BG3] Modding BG3 - Getting Started

[orinEsque]

Index

1. Prerequisites
2. Unpacking Game Files
3. Using the BG3MT Search function
4. Creating a .pak Mod that works with mod managers
5. How to change your mod's version
6. Unpacking an existing mod
7. Modding Best Practices
8. How to change NPC visuals [redirect]
9. How to change Voice using AI [redirect]

[back to index]
1.Prerequisites

1. BG3 Multimodders Tool (BG3MT) - Download
2. Norbyte's Lslib Tool - Download
3. Notepad++ - Download
   
   If you intend to edit/create BG3 meshes in blender:
4. Norbyte's Collada/GR2 Blender plugin - Download

[back to index]
2.Unpacking Game Files

1. Open BG3 Multimodders Tool (BG3MT)
2. Click on "Configuration" & set your BG3.exe path to where is steamlibrary folder is. This should be something like: C:\SteamLibrary\steamapps\common\Baldurs Gate 3\bin\bg3.exe
3. Set your game's document folder to: C:\Users\yourUserrname\AppData\Local\Larian Studios\Baldur's Gate 3
4. Now go to Utilities > Game File Operations > Unpack Game Files
   
5. Unpack the relevant pak file, or all if you have enough disk space.
   ► Which .pak do I need?

   Which .pak do I need?
   If you have space I suggest unpacking everything [200GB]. Makes finding what you need easier
   
   Most Relevant: Code defining the world and NPCs

   • Gustav.pak
   • Shared.pak

   3D models and Textures

   • Models.pak - all 3D meshes and models
   • Textures.pak - Textures that go over the 3D models
   • VirtualTextures.pak - Textures for ingame models, such as armor and clothing.

   Audio

   • Voice.pak - Properly named dialogue files
   • VoiceMeta.pak - Data about above audio files
   • SharedSounds.pak - Badly named audio files
   • SharedSoundBanks.pak - Data about above audio files

   Ingame text

   • English.pak / Your Language.pak - All ingame text and dialogue

   Character Creation & UI

   • Game.pak - files you can edit to alter your Character Ccreator / UI.

   Misc

   • Icons.pak - self explanatory
   • Assets.pak - Not for beginners [defines groups of assets, maybe dialogue trees]
6. Game File Operations > Decompress Unpacked Game Files
   
7. Index > Index Pak Files
   
8. Index > Index Unpacked Files

[orinEsque]

[back to index]
3. Using the BG3MT Search function
Once you have indexed your game files, BG3MT can be used to search for contents of these game files.
Starting with an easy example, let's say I want to find the file that defines what Lorroakan looks like.

1. Click Search Index
   
2. Search "Lorroakan". And set file type to .lsx
3. Scroll down till you find [PAK]CharacterVisuals\_merged.lsf.lsx
   
4. Open this file in notepad++
5. Do a search (Ctrl+F) for "Lorroakan" and it should take you to the section that defines his visuals.
6. What you have here is an xml file. It's similar to bbcode in that it has "tags" that open and close. <mytag> some text </mytag>
   

[orinEsque]

[back to index]
4. Creating a .pak mod that works with mod managers

1. Let's create myFirstMod-v1.0.
2. Create a folder named myFirstMod-v1.0
3. Inside create a folder called "Mods".
4. Inside the "Mods" folder create a unique folder name that corresponds to your mod but without spaces e.g: called myFirstMod. This folder name is important.
   ► you can skip these step now

   1. Within this folder, create a text file called meta.lsx.
      
   2. Go to this website: https://bg3.wiki/wiki/Modding:Creating_meta.lsx
   3. Under the "Creating your meta.lsx manually" section, you will find the contents of your meta.lsx
   4. Copy the code from the site and paste it into your meta.lsx
   5. Open your BG3MT tool > Click Generate to get a new UUID
      
   6. Paste this new UUID into your meta.lsx as shown.
      
   7. It's very important that parent folder of your meta.lsx is the same as the "Folder" name given within the meta.lsx (in pink).
5. Now you can drop the myFirstMod-v1.0 folder into the blue area in BG3MTool.
   
6. Now BG3MT will as you to put Author, Description and Version.
   
7. Make sure you set version to be higher than 0.0.0.0. Otherwise your mod may not work.
8. This will now create myFirstMod-v1.0.zip. It doesn't do anything in the game yet but if you drop it in your mod manager, it will show up as a mod.

[orinEsque]

[back to index]
5. How to change your Mod's version

1. Open BG3 Multi Modders Tool (BG3MT)
2. Go to Utilities > Version Calculator
3. I want version 2.3. So set it and copy the long number
   
4. Paste this in place of the two long numbers indicated as version.
   

[back to index]
6. Unpack an Existing mod

1. If the mod is in a zip file, unzip it.
2. Open BG3MT
3. Drop the .pak file in the blue area
4. Then go to Shortcuts > Unpacked Mods
5. You should see a folder corresponding to the .pak file's name. Congratz, you have unpacked the mod!

[back to index]
7. Modding Best Practices
Only use the necessary assets & make your mod future proof.

1. LSF files in the same file path after SharedDev, Shared, GustavDev, Gustav all merge together into one before the game is loaded. E.g.
   • Public / SharedDev /Content/[PAK]Character_visual/merged.lsf
   • Public / Shared /Content/[PAK]Character_visual merged.lsf
   • Public / GustavDev /Content/ [PAK]Character_visual /merged.lsf
   • Public / Gustav /Content/[PAK]Character_visual /merged.lsf
   • Public / yourmodname /Content/[PAK]Character_visual /merged.lsf.
   All the LSF files from above get merged into one big xml file. With yourmodname/merged.lsf getting priority.
2. Renaming your merged.lsf to random.lsf still works.
3. Multiple .lsf files can be dropped in the same Public/yourmodname/ folder and have the same effect as dropping Gustav/../merged.lsf and GustavDev /../merged.lsf separately. E.g.
   
4. Your mod’s LSF file does NOT need to contain everything from the original file if you use this file convention:
   • Public/Yourmodname/Content/[PAK]Character_visual /renamed.lsf
   This way you can avoid issues like headless cats! being changed in a new patch. And your mod size will be tiny because your .LSF file will only contain the code for the character you changed only. E.g. I have only included Wyll’s variables so instead of a 100000+ lines, I have 2500.
   
5. Note: EVERYTHING between a <node=”Resource”> and </node> has to be included otherwise if you change eye colour in the Resource and leave out the rest. You’ll just have floating eyes.
6. It's best to use the LSV from the latest PatchXHotfixY.pak file instead of the one from Gustav.pak or Shared.pak when you first build your mod.
7. Finally, you can pack your mod into a handy little zip file using bg3-modders-multitool, and we can easily import stuff into BG3 manager. This way we can decide which mod gets priority if two mods have some clashing character Resources.

[Oyster Sauce]

I tried making a mod and it seemed too difficult so I gave up. Now, thanks to this guide, I know I was correct.

[BobT]

I tried making a mod and it seemed too difficult so I gave up. Now, thanks to this guide, I know I was correct.

If a woman can do it, why can't you?

[Kowe]

A rather general question. What programming language is used for Baldur's Gate 3 ? Someone said C# and Lua on a Steam forum post. Is this correct ?
I am only a bit familiar with Java and Python (therefore some general knowledge), but it can't hurt to dive deeper into the code in the long-run.

[rusty_shackleford]

What programming language is used for Baldur's Gate 3 ?

Engine is in C++, scripting is done in their own scripting language that is based on prolog/datalog.

[Kowe]

What programming language is used for Baldur's Gate 3 ?

Engine is in C++, scripting is done in their own scripting language that is based on prolog/datalog.

Thank you very much!
Time to get some good tutorials/books/PDFs for both.

[rusty_shackleford]

What programming language is used for Baldur's Gate 3 ?

Engine is in C++, scripting is done in their own scripting language that is based on prolog/datalog.

Thank you very much!
Time to get some good tutorials/books/PDFs for both.

The only one of the two used by modders will be the latter, but not until they release their devkit.

[Tweed]

I tried making a mod and it seemed too difficult so I gave up. Now, thanks to this guide, I know I was correct.

If a woman can do it, why can't you?

>woman

[AtomicSpaceKitty]

Thank you so much, @orinEsque , for these tutorials. They helped me to figure out how to merge your No Alphabets Lingo file with the Show Approval Ratings mod.

[orinEsque]

Thank you so much, @orinEsque , for these tutorials. They helped me to figure out how to merge your No Alphabets Lingo file with the Show Approval Ratings mod.

Glad I could help!

[gastovski]

Is it possible to convert spells to cantrips? there is a nice paladin overhaul mod on nexus but its a bit tedious to play atm.

[orinEsque]

Is it possible to convert spells to cantrips? there is a nice paladin overhaul mod on nexus but its a bit tedious to play atm.

@Slavic Sorcerer may be able to answer this question

[Slavic Sorcerer]

@Slavic Sorcerer may be able to answer this question

Thanks for tagging me

Is it possible to convert spells to cantrips? there is a nice paladin overhaul mod on nexus but its a bit tedious to play atm.

It is possible. I didn't do it (yet), but part of my Cleric and Paladin mod project (still WIP) was converting NPC spells into Player ones.
Converting a spell to a cantrip shouldn't be too different.

What spell you'd want to convert to a cantrip? I could write a guide on the process.

[gastovski]

i think i have figured it out

► Show Spoiler

new entry "Shout_SearingJudgment"
type "SpellData"
data "SpellType" "Shout"
data "Level" "1"
data "SpellSchool" "Evocation"
data "SpellProperties" "ApplyStatus(SEARING_JUDGMENT, 100, -1)"
data "TargetConditions" "Self()"
data "Icon" "Spell_Evocation_SearingSmite"
data "DisplayName" "h0bea1a15gfd51g4b27g97f9gb1fe730ad0fe;1"
data "Description" "h3a6225adg7b75g4f41g90fdg0e056c2a046d;2"
data "DescriptionParams" "DealDamage(1d6, Fire)"
data "TooltipStatusApply" "ApplyStatus(SEARING_JUDGMENT, 100, -1)"
data "TooltipUpcastDescription" "36971723-b672-41e6-b2cf-b3ff2daddf1e"
data "TooltipUpcastDescriptionParams" "DealDamage(1d6,Fire);Distance(3)"
data "CastSound" "Action_Cast_Paladin_HolyRebuke"
data "TargetSound" "Action_Impact_Paladin_HolyRebuke"
data "UseCosts" "BonusActionPoint:1"
data "SpellAnimation" "83fb0115-57dd-4cce-ac40-87182b2865e2,,;,,;4b27cbbb-6774-4037-a620-80901b11a10f,4b27cbbb-6774-4037-a620-80901b11a10f,4b27cbbb-6774-4037-a620-80901b11a10f;52ffbb9a-a97b-448e-acaf-06344ce9be87,,;42014429-21fb-412d-bba6-0f8216f5e502,,;,,;43fa5e31-ad7e-47a9-9ca2-f6d40ba8e1cf,,;032cf56a-3808-45ad-9991-740431d9c14f,,;4b385541-a3a3-429d-93ae-dffa6da50050,,"
data "VerbalIntent" "Buff"
data "SpellStyleGroup" "Class"
data "HitAnimationType" "MagicalNonDamage"
data "SpellFlags" "HasVerbalComponent;HasSomaticComponent;IsSpell"
data "PrepareEffect" "8fde100d-8e9a-4469-8383-61ddeaa9e365"
data "CastEffect" "0a12c4b1-5b5f-4dca-81a0-88371c9a12a8"
data "TargetEffect" "26e8bd29-bc16-4077-a9ed-e8bbbfa93bcf"

i have removed spell slot costs so instead converting it only costs bonus action i hope it wont be op later, thanks for response