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I copied the folders to a USB stick and merged them together on my PC, then put them back into the Steam Deck data folder.īoth mods seem to be working properly and I haven't had any issues yet, so I'll probably add a few more mods soon. One hiccup was that EVE and UFO3P use the same data folders (textures and meshes), and because UFO3P capitalizes the folder names, they didn't merge together. (I initially used the Launcher, but later edited the plugins.txt file to make sure the order was properly arranged). I also installed EVE, which was far simpler-I just dropped the files into my Data folder and added the ESM to my load order. I added the ESM file to my load order through the Data Files option in the Fallout 3 Launcher. After I had the files into my Fallout3 Data folder, I edited the non-Steam game link to point to the UFO3P uninstaller, ran that to clean up the files in the non-game location, then removed the non-Steam app from my Steam library. I think UOFO3P also tries to edit a few other things (iNumThreads, etc.), but I wasn't sure whether that was necessary with Proton, so I left that alone. The installer couldn't do the INI edits that it tried to do, so I manually edited my Fallout.ini file with "bInvalidateOlderFiles=1" to make mods work.
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When it was done, I found the new Steamapp folder that it created, located the ESM and BSA files and Data folders that it put there, and copied them to my Fallout 3 install.
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I couldn't direct it to my Fallout 3 install location (on my SDXC card), so I let it install to the default location (C:/Program Files/Bethesda Softworks/Fallout 3). I added the UFO3P installer to Steam as a non-Steam app from desktop mode, then ran it with Proton compatibility. I managed to install an older version of the Unofficial Fallout 3 Patch (I used an older one so it didn't need FOSE, since I wasn't ready to tackle that whole can of worms).
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I don't think you'll be able to point a mod manager to the file locations it needs to access. The INI files are outside of the game's install folder, and SteamOS makes a self-contained folder for each app containing those locations. I managed to install a few mods for Fallout 3, but it's tricky.
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