Sekiro uses one profile-level S0000.sl2 file, so a file replacement can roll back several in-game slots at once. The safest routine is therefore simple but strict: close the game, copy the whole account-ID directory, keep more than one dated generation, and only then experiment. Steam Cloud is another revision source; if a manual restore appears to revert itself, solve the synchronization conflict before overwriting the folder again.
Choose the correct backup boundary
For Sekiro: Shadows Die Twice, the researched PC save location is Windows: %APPDATA%Sekiro<user-id>S0000.sl2 | Linux / Steam Play: Steam Play: <SteamLibrary-folder>/steamapps/compatdata/814380/pfx/. The known save file or folder pattern is S0000.sl2. Copy the entire Sekiro account-ID folder with the game closed. Keep multiple dated versions because the game continually updates the same container. Copying the complete documented save boundary is safer than selecting one visually obvious file, because companion metadata, indexes, backups, or multiple slots can be required together.
Make an offline copy before changing anything
Close the game first, wait for the active launcher to finish writing, then copy the save data to a separate folder that the game and sync client do not watch. Label the copy with the game, storefront, profile, and date. Documented launcher context: Steam. The user-ID directory is part of the save context. Do not assume a copied S0000.sl2 belongs to the active Steam identity.
Account for cloud saves
Steam Cloud is documented. Before restoring an older backup, decide which copy should win. If the game or launcher starts while an older manual copy is in place, synchronization can replace it before you confirm that it works. Keep the untouched backup outside the live save path until the restored progress has been opened and saved normally.
Restore without changing format assumptions
The Steam PC profile is a single S0000.sl2 container under an account-ID directory. Multiple in-game slots are not separate operating-system files. Compatibility note: One .sl2 container can hold multiple in-game slots. File-level replacement rolls back the profile container, not one isolated character slot. Restore into the matching storefront/profile context whenever possible. Do not rename a save extension, move a folder into a different container type, or assume a console/mobile copy is equivalent unless a tested migration path specifically says so.
Recovery fallback
If a restore is replaced on launch, compare Steam Cloud state and modification times. Keep the original local file before testing any imported container. If the restored copy fails, put the untouched original back first. Then compare location, account/profile, cloud state, and the full directory structure before trying a different backup. The objective is reversible recovery, not repeated destructive experiments on the only copy.
Verification context: Windows path, S0000.sl2 filename, Steam Play behavior, and Steam Cloud support were reviewed against current PCGamingWiki coverage.