Slay the Spire is different from the usual one-folder save model: PCGamingWiki lists preferences, runs, saves, and betaPreferences as game data. That means “backup the save file” is incomplete advice. A user may restore card/progression information yet lose an active run or related preferences if only one directory is copied. SaveEditor therefore treats the four directories as one logical backup set for standard desktop builds while keeping the Microsoft Store package path separate.
Known Slay the Spire save-file structure
The researched filename or folder pattern is Multiple files across preferences, runs, saves, and betaPreferences rather than one universal slot file.. File-extension context: No single extension is sufficient to identify every relevant save record. The documented format notes are: Slay the Spire stores meaningful state in several sibling directories under the installation resources for standard desktop builds. Backing up only saves can omit preferences/unlocks or run state.
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. Unlock/progression data and an in-progress run are not necessarily represented by the same file. A partial directory copy can therefore restore one aspect but not another. 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: Desktop builds: <path-to-game>preferences, <path-to-game>runs, <path-to-game>saves and betaPreferences ; Microsoft Store: %LOCALAPPDATA%PackagesHumbleBundle.SlayTheSpire_q2mcdwmzx4qjaLocalCacheLocalMicrosoftWritablePackageRootsaves. Storefront context: Steam, GOG, Microsoft Store. The Microsoft Store sandbox path differs significantly from Steam/GOG. Standard desktop installs can keep data alongside game resources, so reinstall/move operations deserve an explicit backup first. 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
Back up preferences, runs, saves, and betaPreferences together before reinstalling or moving the game. On Microsoft Store, preserve the package-local save path separately. 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 support are documented depending on edition. 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 ascension/unlocks or the current run do not match after restoration, compare all four data directories rather than repeatedly overwriting the saves folder alone. Those questions require a verified parser/profile or a game-specific source, not a generic format guess.
Verification context: Reviewed against current PCGamingWiki Slay the Spire save-data locations and multi-directory layout.