Baldur’s Gate 3 makes the folder boundary important: each save folder contains the .lsv archive and related slot context. Backing up the whole folder avoids separating the main payload from supporting files. Campaigns can also be sensitive to mods, so SaveEditor.com treats mod compatibility as part of restoration rather than calling every failed load corruption. Larian cross-save is useful for recent saves, but a complete local archive is still the better long-term backup.
Known Baldur's Gate 3 save-file structure
The researched filename or folder pattern is <save-folder><save-name>.lsv. File-extension context: .lsv The documented format notes are: Each campaign save is stored in its own folder and includes an .lsv archive. Preserve the whole save folder rather than extracting only the archive when making a normal backup.
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. An .lsv can be structurally valid but still depend on mods or game versions that are not present on the destination system. 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: %LOCALAPPDATA%Larian StudiosBaldur's Gate 3PlayerProfilesPublicSavegamesStory | macOS: $HOME/Documents/Larian Studios/Baldur's Gate 3/PlayerProfiles/Public/Savegames/Story/ | Linux / Steam Play: $XDG_DATA_HOME/Larian Studios/Baldur's Gate 3/PlayerProfiles/Public/Savegames/Story/. Storefront context: Steam, GOG Galaxy. The same Larian profile hierarchy is used across desktop platforms, with OS-specific base directories. Steam also exposes a remote cloud area. 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 entire Story directory or selected complete save folders. For heavily modded campaigns, also keep the mod configuration required by that campaign. 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 is documented. Larian account cross-save can synchronize a limited set of recent saves across supported PC storefronts/platforms. 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: When a campaign save fails after migration, check the exact save folder, mods, and profile before assuming the archive is damaged. Cloud cross-save only covers supported recent saves, not every local backup. Those questions require a verified parser/profile or a game-specific source, not a generic format guess.
Verification context: Windows, macOS, Linux, Steam remote/cloud, and Larian cross-save notes were reviewed against current PCGamingWiki coverage.