Fallout 3 and Fallout: New Vegas have a great modding community, but most mods require launching the game through a mod manager like Fallout Mod Manager (FOMM), or by launching the Fallout Script Extender (FOSE), both of which exist independent of Steam.

I know I can 'Add a non-steam game' to my library (and in fact have been doing this for a while), but is there any way I can get Steam to launch FOMM or FOSE directly, by clicking the 'Play' button on the actual game?

This will enable me to use all my favourite mods, as well as continuing to utilise some of the Steam community benefits of launching the actual game.

2 Answers 2


You can actually rename the FOSE or FOMM launchers to 'FalloutLauncher.exe', which is the executable Steam looks for when launching the game. Steam will then launch the appropriate program, but still think that it is Fallout.

For example, I did these steps with FOSE:

  • Navigate to Fallout 3/New Vegas's folder under steamapps.
  • Change the FalloutLauncher.exe file to be a different name, such as FalloutLauncher-orig.exe (in case you want to revert).
  • Create a copy of the fose-loader.exe file, and rename it to FalloutLauncher.exe (Leave the original named as fose_loader.exe, as FOMM will look for this file when you launch FOSE through it.)
  • Click Play in Steam. It should launch the game with FOSE.

I chose to do this with FOSE instead of FOMM, because FOSE launches the game directly. If I want to access FOMM, I still have it's link as a 'Non-Steam game'.

  • 1
    This should also work with Skyrim and SKSE and I'd imagine it would also work with Oblivion and OBSE.
    – 3ventic
    Sep 1, 2013 at 11:18
  • @3ventic - I wasn't sure whether Skyrim/Oblivion have separate executables like FO3/NV, as I don't own them. That's awesome if they do however. It will work with any game that uses a separate launcher (i.e. was added to steam, not optimised for it)
    – Robotnik
    Sep 1, 2013 at 11:24
  • I know Skyrim does, but I haven't had Oblivion installed in such a long time that I don't remember anymore. Someone else can confirm if they wish.
    – 3ventic
    Sep 1, 2013 at 11:27
  • I just opened NMM, brought up the FO3 launcher with Steam and then hit play on NMM so Steam recorded that I was playing FO3. But I just wanted Steam to track my hours. Sep 1, 2013 at 20:13
  • 1
    @3ventic - To that end, I wrote up a similar answer on a Skyrim question that asked the same thing.
    – Robotnik
    Sep 2, 2013 at 3:43

Sorry for the necro, I just found a great little way to do this.

First, rename fose-loader.exe to Fallout3Beta.exe

Then rename Fallout3.exe to Fallout3ng.exe

It seems that if the launcher cannot find Fallout3.exe it looks for Fallout3Beta.exe, and if fose-loader.exe can't find Fallout3.exe, it looks for Fallout3ng.exe

  • This is a preferable solution just in case an official patch is ever released that attempts to overwrite Fallout3.exe. Not that it is at all likely, but better safe than sorry.
    – KOVIKO
    Nov 12, 2015 at 14:15

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .