Octopath Traveler II looks similar to the first game at a glance, but its Steam directory adds an explicit Steam branch and current transfer reports call out SystemData.sav alongside SaveData slot files. That makes whole-folder backup more important than copying a single large slot. SaveEditor records the current Microsoft Store WGS path separately and avoids claiming that a Game Pass blob can simply be renamed into a Steam SaveData file without the system-data context.
Known Octopath Traveler II save-file structure
The researched filename or folder pattern is SaveData*.sav plus SystemData.sav on current Steam builds.. File-extension context: .sav The documented format notes are: The sequel uses a Steam-specific Documents branch and separates slot saves from system data. Microsoft Store uses WGS. SystemData should be backed up with the slots because it can contain state not represented by one SaveData file.
Why an extension is not enough
A save filename can identify a likely container, but it does not prove the internal schema, game version, checksum rules, encryption state, or editability. Do not restore only one SaveData slot if you are trying to reproduce the complete profile state. Cross-store migration may need both slot and system payload handling. SaveEditor therefore separates file identification from Tool compatibility and only labels a game-specific Tool Verified when its exact profile/version evidence passes the runtime gate.
Where the format is stored
PC save locations: Windows: Steam: %USERPROFILE%DocumentsMy GamesOctopath_Traveler2Steam<user-id>SaveGames ; Microsoft Store: %LOCALAPPDATA%Packages39EA002F.OCTOPATHTRAVELER2_n746a19ndrrjgSystemAppDatawgs. Storefront context: Steam, Microsoft Store. Steam and Game Pass storage differ. Current community migration notes identify both slot-sized files and separate system data in WGS. This matters because two releases can use different containers or companion files even when the visible slot name is similar.
Back up before inspecting or editing
Copy the whole SaveGames directory on Steam, including SystemData.sav. For Microsoft Store, preserve all WGS containers before identifying slot and system payloads. A read-only viewer is lower risk than a writer, but the live save should still be copied first. Cloud context also matters: Steam Cloud and Xbox Cloud are documented. Keep the original bytes available so any experiment can be reversed without relying on a cloud service or automatic backup.
What this reference does not claim
This page does not infer an undocumented checksum algorithm, encryption key, compression layer, or cross-store conversion from the file extension. Troubleshooting evidence: If an imported slot seems blank or incomplete, check whether SystemData came from the same snapshot and whether Steam Cloud restored the previous directory. Those questions require a verified parser/profile or a game-specific source, not a generic format guess.
Verification context: Reviewed against current PCGamingWiki Octopath Traveler II save path and 2026 community notes describing SystemData during WGS-to-Steam transfers.