Fallout 3 shares broad engine lineage with New Vegas but uses a different game directory and should never be restored into FalloutNV merely because both use .fos files.
Where Fallout 3 stores PC saves
The researched save-location boundary is Windows: %USERPROFILE%DocumentsMy GamesFallout3Saves. The known file or folder pattern is *.fos save files. This is the practical starting point because launcher, profile, and storefront context can change which copy is active even when two folders look similar.
Storefront and profile differences
Documented launchers or storefronts: Steam, GOG. The active Steam, GOG installation determines which local profile and cloud copy can overwrite the save. Identify the storefront and account before restoring files. When looking for a missing save, identify the executable/storefront you actually launched and the user/profile that created the progress before copying anything between directories.
Cloud synchronization
Cloud behavior is storefront-dependent; an offline Saves backup is the stable recovery copy. A cloud service should be treated as another copy of the save, not as proof that the local folder is disposable. Before a manual restore, let synchronization finish, make an offline backup, and avoid starting the game while files are being replaced.
What the files represent
Fallout 3 uses .fos save records in the My Games profile. Save compatibility can depend on DLC and mods, so restoration should preserve the surrounding game configuration. The current filename/folder evidence is *.fos save files. File-extension context: .fos A location guide does not claim that every file in the directory is safe to edit or that files from another storefront are automatically interchangeable.
If the save is not where expected
If progress is missing after a restore, confirm the active Windows account, storefront/profile, cloud state, and exact directory first. Restore the untouched backup before experimenting with individual files or older autosaves. Also check redirected Documents folders, Steam Play prefixes, account IDs, and launcher-specific containers where applicable. Preserve every candidate copy before testing a restore so troubleshooting does not destroy the only surviving version.
Verification context: Windows save location, file-boundary, launcher/cloud, and backup notes were reviewed against the linked game-specific references for Fallout 3. This Game Hub is documentation only and does not claim a new game-specific Save Editor.
Recorded Phase 40 evidence boundary
This Phase 40 entry is grounded in the researched PC save boundary for Fallout 3: Windows: %USERPROFILE%DocumentsMy GamesFallout3Saves The recorded file or folder pattern is *.fos save files. These concrete identifiers are retained so backup, transfer, recovery, and editing preparation remain tied to the documented game/storefront context instead of a generic extension guess.