claude-home/baldurs-gate-3-coop-friend-setup.md

BG3 Coop Friend Setup (Linux)

Quick setup guide for joining a modded BG3 coop game. Uses pre-packaged mod archive for identical setup.

You need: The bg3-mods-clean.zip file from your coop partner.

---

Step 1: Prerequisites

Install GE-Proton

Required for running BG3 Mod Manager on Linux.

1. Download latest from: https://github.com/GloriousEggroll/proton-ge-custom/releases
2. Extract to: ~/.local/share/Steam/compatibilitytools.d/

Example:

mkdir -p ~/.local/share/Steam/compatibilitytools.d
cd ~/.local/share/Steam/compatibilitytools.d
tar -xf ~/Downloads/GE-Proton9-27.tar.gz

Run BG3 Once

Launch BG3 via Steam at least once to create the wine prefix. You can quit after the main menu loads.

---

Step 2: Find Your Paths

You need two paths. Run this to find them:

# Find your BG3 install
find ~/.steam /mnt -type d -name "Baldurs Gate 3" -path "*/common/*" 2>/dev/null

# Find your wine prefix
find ~/.steam /mnt -path "*/compatdata/1086940/pfx" 2>/dev/null

Write these down:

• BG3_INSTALL: (e.g., /mnt/games/steam/steamapps/common/Baldurs Gate 3)
• WINEPREFIX: (e.g., /mnt/games/steam/steamapps/compatdata/1086940/pfx)

---

Step 3: Install Script Extender

# Set your BG3 install path from Step 2
BG3_INSTALL="/path/to/Baldurs Gate 3"

# Download and extract
curl -sL $(curl -s https://api.github.com/repos/Norbyte/bg3se/releases/latest | grep browser_download_url | head -1 | cut -d'"' -f4) -o /tmp/se.zip
unzip -o /tmp/se.zip -d "$BG3_INSTALL/bin"

Verify: ls "$BG3_INSTALL/bin/DWrite.dll" should exist.

---

Step 4: Install BG3 Mod Manager

mkdir -p ~/Applications/BG3ModManager
cd ~/Applications/BG3ModManager

# Download latest release
curl -sL $(curl -s https://api.github.com/repos/LaughingLeader/BG3ModManager/releases/latest | grep "browser_download_url.*zip" | head -1 | cut -d'"' -f4) -o BG3MM.zip
unzip BG3MM.zip && rm BG3MM.zip

---

Step 5: Create Launcher Script

Save this to ~/bin/launch-bg3mm.sh:

#!/bin/bash
set -euo pipefail

# EDIT THESE to match your system (from Step 2)
WINEPREFIX="/path/to/compatdata/1086940/pfx"
GE_PROTON="GE-Proton9-27"

BG3MM_DIR="$HOME/Applications/BG3ModManager"
WINE64="$HOME/.local/share/Steam/compatibilitytools.d/$GE_PROTON/files/bin/wine64"

cd "$BG3MM_DIR"
WINEPREFIX="$WINEPREFIX" WINEFSYNC=1 "$WINE64" BG3ModManager.exe "$@"

Make executable:

chmod +x ~/bin/launch-bg3mm.sh

---

Step 6: Import Mods

1. Launch BG3MM:

   ~/bin/launch-bg3mm.sh
   

2. If it asks for BG3 folder, navigate to your BG3_INSTALL path from Step 2

3. File → Import Order & Mods from Archive → select bg3-mods-clean.zip

4. File → Export Order to Game

5. Close BG3MM

---

Step 7: Configure Steam Launch Options

Right-click BG3 in Steam → Properties → Launch Options:

gamemoderun mangohud %command% --skip-launcher --dx11

The --skip-launcher is required - the Larian Launcher doesn't work properly in Proton.

---

Step 7b: SteamTinkerLaunch Config (Optional)

If you use STL, create ~/.config/steamtinkerlaunch/gamecfgs/id/1086940.conf:

# Baldur's Gate 3 - Modded Coop Configuration

##########################
## PROTON
##########################
USEPROTON="GE-Proton9-27"
GAMEARGS="--skip-launcher"

##########################
## NVIDIA RTX
##########################
PROTON_ENABLE_NVAPI="1"
PROTON_HIDE_NVIDIA_GPU="0"
VKD3D_CONFIG="dxr"
DXVK_ASYNC="1"
DXVK_HDR="1"
DXVK_LOG_LEVEL="none"

##########################
## SCRIPT EXTENDER
##########################
USE_WINEDLLOVERRIDE="1"
WINEDLLOVERRIDE="DWrite.dll=n,b"

##########################
## PERFORMANCE
##########################
USEGAMEMODERUN="1"
USEMANGOHUD="1"
PROTON_NO_FSYNC="0"
PROTON_NO_ESYNC="0"
PROTON_FORCE_LARGE_ADDRESS_AWARE="1"

##########################
## DISPLAY
##########################
PROTON_ENABLE_HDR="1"
ENABLE_HDR_WSI="1"
USEGAMESCOPE="0"

##########################
## DEBUGGING (disabled)
##########################
PROTON_LOG="0"
STLWINEDEBUG="-all"

Key settings explained:

• WINEDLLOVERRIDE="DWrite.dll=n,b" - Loads Script Extender (native, then builtin)
• PROTON_ENABLE_NVAPI="1" - Enables NVIDIA driver passthrough for RTX/DLSS
• PROTON_HIDE_NVIDIA_GPU="0" - Don't hide GPU from game (needed for RTX)
• VKD3D_CONFIG="dxr" - Enable ray tracing support
• GAMEARGS="--skip-launcher" - Bypass broken Larian Launcher

---

Step 8: Verify

1. Launch BG3 via Steam
2. Check main menu bottom-left shows Script Extender version
3. Start a new game - mods should be active

---

Included Mods (16 .pak mods via BG3MM)

Category	Mod	Purpose
Dependencies	VolitionCabinet	Framework for auto-send mods
	Mod Configuration Menu	Settings UI
	Mark Books as Read	Required by auto-send books
UI	ImpUI	UI improvements
	Better Inventory UI	Color-coded items
	Better Containers	Improved container UI
	Better Hotbar 2	More hotbar slots
	BagsBagsBagsReforged	Auto-sort containers
QoL	Weightless Consumables	No potion/scroll weight
	Carry Weight Increased	x10 carry capacity
	Auto Send Food To Camp	Food auto-transfers
	Auto Send Read Books	Books auto-transfer
	Wifi Potions	Share potions across party
	Fix Stragglers	Auto-teleport stuck companions
	MoveFaster	2x movement speed
	TransmogEnhanced	Change gear appearance

---

Optional: Native Mods (Client-Side Only)

These are DLL mods that go in the bin/ folder, NOT managed by BG3MM. They don't need to be synced for coop - each player can choose to use them independently.

Mod	Purpose
Native Mod Loader	Framework for native DLL mods
WASD Character Movement	Direct keyboard movement instead of click-to-move
Native Camera Tweaks	Unlocked camera controls (zoom, rotation, etc.)

Installing Native Mods

BG3_BIN="/path/to/Baldurs Gate 3/bin"

# 1. Download from NexusMods:
#    - Native Mod Loader: https://www.nexusmods.com/baldursgate3/mods/944
#    - WASD: https://www.nexusmods.com/baldursgate3/mods/781
#    - Native Camera Tweaks: https://www.nexusmods.com/baldursgate3/mods/945

# 2. Backup original bink2w64.dll
cp "$BG3_BIN/bink2w64.dll" "$BG3_BIN/bink2w64_original.dll"

# 3. Extract NativeModLoader's bink2w64.dll to bin/
unzip NativeModLoader*.zip -d /tmp/nml
cp /tmp/nml/bin/bink2w64.dll "$BG3_BIN/"

# 4. Create NativeMods folder and extract WASD/Camera
mkdir -p "$BG3_BIN/NativeMods"
unzip WASD*.zip -d /tmp/wasd
unzip "Native Camera*.zip" -d /tmp/camera
cp /tmp/wasd/bin/NativeMods/* "$BG3_BIN/NativeMods/"
cp /tmp/camera/bin/NativeMods/* "$BG3_BIN/NativeMods/"

After installation, bin/NativeMods/ should contain:

• BG3WASD.dll + BG3WASD.toml
• BG3NativeCameraTweaks.dll + BG3NativeCameraTweaks.toml

---

Troubleshooting

BG3MM won't launch

Wineserver mismatch: Kill existing wineserver and retry:

wineserver -k
~/bin/launch-bg3mm.sh

Wrong wine: Make sure you're using GE-Proton's wine64, not system wine.

Game won't start / stuck on "Running"

Make sure --skip-launcher is in your Steam launch options.

"Version mismatch" with coop partner

Both players must have:

• Same game version (check Steam)
• Same mods (use the same archive)
• Script Extender showing in main menu

---

Quick Reference

Item	Path
Script Extender	<BG3_INSTALL>/bin/DWrite.dll
Mods folder	<WINEPREFIX>/drive_c/users/steamuser/AppData/Local/Larian Studios/Baldur's Gate 3/Mods/
BG3MM	~/Applications/BG3ModManager/
GE-Proton	~/.local/share/Steam/compatibilitytools.d/GE-Proton9-27/