RimWorld makes the file format comparatively transparent—.rws saves are XML—but that does not make them context-free. A colony serializes references to the game version, DLC, mods, world objects, pawns, maps, and many definitions supplied by the active content set. SaveEditor therefore treats a proper backup as the .rws file plus environment notes. This is especially important before removing a mod or upgrading a heavily modded colony, because an XML parser succeeding does not prove that RimWorld can reconstruct every referenced definition.
Prepare the source PC
On the source system, identify the actual RimWorld save root: Windows: %USERPROFILE%AppDataLocalLowLudeon StudiosRimWorld by Ludeon StudiosSaves. The expected file/folder pattern is *.rws; manual names plus Autosave-* records.. Close the game, let the active launcher finish writing and synchronizing, then make a complete offline copy rather than transferring a file that may still be open.
Preserve storefront and profile identity
Documented storefronts: Steam, GOG, Epic Games Launcher. The save file is human-readable XML, but it is highly version/mod dependent. Editing XML without understanding cross-references can create a loadable-looking file that fails later. A transfer between two PCs is simplest when both systems use the same storefront/account/profile context. If the destination uses a different store or container, treat that as a migration problem rather than an ordinary restore.
Move the complete save boundary
Back up the entire Saves folder and also record the RimWorld version, DLC set, and mod list/load order that produced an important colony. Put the copied data on the destination only after confirming the destination save path. If the game creates a new empty save first, keep that new folder as another backup so you can compare structures and revert.
Handle cloud sync deliberately
Steam Cloud is commonly used; the official/community wiki documents platform-specific save directories. Decide whether the local transferred copy or cloud copy should be authoritative before launching the game. If possible, preserve both. After the transferred save loads correctly, make a fresh in-game save and let the launcher synchronize normally.
Check compatibility before blaming the transfer
RimWorld saves are XML-based .rws files and embed world/colony state plus references to active DLC/mod content. The game can show the save-data location from its settings UI. Compatibility note: A .rws file can be structurally valid XML yet incompatible with a different mod set or game version. Missing definitions are a compatibility problem, not automatically file corruption. If the destination does not see the transferred progress, If a colony fails after an update or mod change, restore the save and matching mod environment together. Use the in-game “Show” save-data-location action when uncertain about the active folder. Verify game edition/version, store, profile IDs, redirected folders, and mod/DLC dependencies before editing the save itself.
Verification context: Reviewed against the current RimWorld Wiki Save file documentation and current PC save-location conventions.