Special thanks to Steam user steph.mp4 for troubleshooting. Special thanks to the TheMinotauros and Youtube channel @Lucifer-vw9wo- their guide and video really helped me figure this out.

TheMinotauros' guide (https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3026844989)

Lucifer-vw9wo note: their method does not use Lutris

Before starting, make sure you do not have BG3 running.

Switch Steam Deck to Desktop Mode. Head over to the Discover Store and search for 'Lutris'. Download it.

Head over to https://github.com/LaughingLeader/BG3ModManager/releases/tag/1.0.12.9 to download the BG3 Mod Manager

Open Dolphin explorer and go to “/home/deck/” and create a “Mods” folder. Inside the new “Mods” folder, create a new folder and name it “BG3”. Inside the newly created “BG3” folder, create a new folder and name it “BG3ModManager”.

Move the BG3 Mod Manager download (should be a zip file) to the BG3ModManager folder in the Mods folder and extract the contents to it.

Open Lutris, select the hamburger menu (three lines) near top right of screen and select “Add games”, and then “Add locally installed game”


Set “Name” to “BG3 Mod Manager” and select “Wine (Runs Windows games)” as Runner


Switch to “Game options” tab.

• For "Executable", input: /home/deck/Mods/BG3/BG3ModManager/BG3ModManager.exe

• For "Wine prefix", input: /home/deck/Mods/BG3/wine_pfx

Click “Save”

On Lutris, select “Wine” on the left side under “Runners”. Select the newly created BG3 Mod Manager tile. At the bottom of the Lutris screen, click the arrow next to the wine glass icon. Select “Winetricks” from the popup options list.


Wait for the Wine configuration to update. When it finishes, you should see popup window to choose a wineprefix. Click the bubble for “Select the default wineprefix” and click “OK”


On the next screen, you will select the bubble for “Install a Windows DLL or component” and click “OK”

On the next screen, select the package for “dotnet8desktop” and click “OK”. NOTE: click “Cancel” when prompted with the “What you like to do to this wineprefix?” screen again.

On Dolphin, go to "/home/deck/mods/BG3/wine_pfx/drive_c/users/deck/AppData/Local/". Right click on an empty space inside the folder and select “Create New”, followed by “Link to File or Directory”. Set “Name for new link” to “Larian Studios”. For “File or directory to link to”, click the icon after the field and select “Directory”. Paste /home/deck/.steam/steam/steamapps/compatdata/1086940/pfx/drive_c/users/steamuser/AppData/Local/Larian Studios/ into the field

This is what both fields should look like:

Return to Lutris, select BG3 Mod Manager tile and click “Play” at the bottom

Upon running the mod manager, go to “Settings” and “Open Preferences” (Preferences menu may open automatically when you first launch the mod manager)

• Set “Game Data Path” to Z:\home\deck\.steam\steam\steamapps\common\Baldurs Gate 3\Data
  
  
• Set “Game Executable Path” to Z:\home\deck\.steam\steam\steamapps\common\Baldurs Gate 3\bin\bg3.exe
  
  
• Set “Override App Path” to Z:\home\deck\.steam\steam\steamapps\compatdata\1086940\pfx\drive_c\users\steamuser\AppData\Local\Larian Studios\Baldur's Gate 3

Click the blue floppy disk icon on the top left to save

Download mods from Nexus. You can drag and drop the zip files directly into the Mod Manager window. It should show up in “Active Mods” pane (left side). If it shows up in “Inactive Mods" pane (right side), simply drag it over to the “Active Mods” pane.

As you can see, I downloaded the Vessnelle_Hair1 mod and dragged the zipped file to my mod manager and it shows up under “Active Mods”


Click "Export" to complete

Head to https://github.com/Norbyte/bg3se and download the latest release. NOTE: It is not recommended to download Script Extender from Nexus as it is not the official version. Use the github link to get the official version.

The download will be a BG3SE-Updater zip file. Extract it and you should see a DWrite.dll file.


Copy and paste this dll in your Baldur’s Gate 3 bin folder at /home/deck/.steam/steam/steamapps/common/Baldurs Gate 3/bin/


Go to your Steam library and access Baldur’s Gate 3 properties by right clicking on it. In “Launch Options”, enter the following command:

WINEDLLOVERRIDES="DWrite.dll=n,b" PROTON_NO_ESYNC=1 %command%

This command helps ensure that the game displays text correctly, especially with mods that add new text or menus. Additionally, it improves stability when using mods like the Script Extender, which might cause crashes or issues if Proton’s default settings are used.

Launch Baldur’s Gate 3 from either desktop or gaming mode. Once the main menu loads, you can see that Script Extender was successfully added on the bottom left corner of the screen:

Happy gaming!