How to install Fallout 4 Mods

I ) Mods Prerequisites – Tools that make life easier

Must Haves

  • a “Data Compression Utility” like 7zip, WinRAR, IZArc or TUGZip -> to extract file archives
  • Nexus Mod Manager (NMM) -> The official Mod Manager. Currently in beta stage and regarding tools not as powerful as FOMM, but more features will follow
  • Fallout Mod Manager (FOMM) -> optional Fallout Launcher providing very useful Modding-Tool, like BSA browser, BSA creator and TESsnip
  • Fallout Script Extender (FOSE) -> many Mods require its additional scripting commands to work
If you moved your DLCs from the Live location into your Data folder or if you use FOSE, read the “Point VII) Where Have All the Savegames Gone “.

Recommended Additions

  • FO3Edit -> detects Conflicts between Mods, a powerful tool for Mod editing
  • Better Oblivion Sorting Software for Fallout 4 (BOSS for FO3) -> sorts your load order automatically
  • Fallout Mod Sorter (FOMS) -> another load order helper
  • ArchiveInvalidation Invalidated -> does the whole “ArchiveInvalidation”
  • Games for Windows LIVE Disabler -> disables GfWL and moves your DLCs into your game folder
  • Fallout Installation Cleaner (FOIC) -> cleans up your Fallout; removes Mods, 3rd party tools, … etc

II ) Installing Mods

Mods come as package -> first you need to extract them to a temporary location by using a tool like 7zip. Examine the files / folders of the Mod you’ve unpacked to get a quick overview.
Example of an unzipped Mod under XP and Vista / Windows7

Installing Mods (1) Installing Mods (2)

You’ll find files with ending *.esp or *.esm and maybe additional folders like textures, meshes or sound.
After you unpacked a lot of Mods, you’ll consider each result as quite unique, but generally the structure is almost the same.

Anyway, there are two common rules you should keep in mind:

  1. All Mods have to be placed into the Data Directory of your Game.
  2. The folder structure must be correct.

The Data Folder
-> The default path for DVD Versions is C: \ Program Files \ Bethesda Softworks \ Fallout 4 \ Data
You may have customised the install path to something else e.g. C: \ Games \ Fallout…
That’s why in some READMEs you’ll find the term “< install path > \ Fallout 4 \ Data \”
-> The default path for Steam Versions is C: \ Program Files \ Steam \ steamapps \ Common \ Fallout 4 \ Data
To avoid issues under Vista and Win7, the install location of Steam can be customised, see point #V .29 Installing Fallout

The Folder Structure

Many Mods only contain Plugins, others just Folders – usually you’ll find both.

Files that belong into the Data-Dir

  • ESP = Elder Scrolls Plugin => Files with ending *.esp
  • ESM = Elder Scrolls Master => Files with ending *.esm
  • BSA = Bethesda Softworks Archive => Files with ending *.bsa (seldom part of user created Mods)

Files that belong into the Data-Dir (1) Files that belong into the Data-Dir (2) Files that belong into the Data-Dir (3) Files that belong into the Data-Dir (4)

Folders that belong into Data-Dir

  • existing by default: Music, Shaders, Video
  • added by yourself: Textures, Meshes, Sound

Folders that belong into Data-Dir (1) Folders that belong into Data-Dir (2)

Don’t think too complicated, just copy & paste Plugins / Masterfiles and Folders like Textures, Meshes, Sound or Music as they are (with all its content) into the Data Folder.

Folders that belong

If Windows tells you that such a folder already exists, overwrite.

If Windows tells


III ) To get Mods working

Many Mods (e.g. Body Replacer, Weapon Mod Kits, Armor Mods, etc) require something which is called “ArchiveInvalidation”. This is the process to recognise certain new files which have been placed into the Data folder.
-> It’s recommended to use the little tool ArchiveInvalidation Invalidated.
-> Unzip, run it, activate it

Many Mods
The whole Archive Invalidation will be done.

If you use another Method such as provided by FOMM or if you want to use your own customised ArchiveInvalidation.txt file
instead of AI-Invalidated, make sure that bInvalidateOlderFiles=0 is set to 1 in your Fallout.ini found in:
\ Documents \ My Games \ Fallout4 \

Finally check your G.E.C.K. Mods (*.esp) at your Fallout Launcher or use FOMM

Finally check your

–> finished, enjoy the game