Always keep a backup of your save data. Never delete a copy of your save data unless you have made sure another viable copy exists.

Save data for Dark Souls III is stored in a folder called DarkSoulsIII (shocking, I know). See the "Save data locations" section for help finding that folder.

Once you're in the DarkSoulsIII folder, you should see a folder with a unique name that contains a file called DS30000.sl2. Move that folder to the DarkSoulsIII folder on another computer to transfer your save data!

If you see more than one folder inside the DarkSoulsIII folder, take a look at the "Identifying your save data folder (optional)" section.

Save data on Windows is usually stored at C:\Users\<Your Username>\AppData\Roaming\DarkSoulsIII. You can get to the AppData folder quickly by pressing [Windows Key]+[R], then typing "%appdata%" in the text box that appears.

From what I can tell, save data on Linux is usually stored at /home/<Your Username>/.steam/steam/steamapps/compatdata/374320/pfx/drive_c/users/steamuser/Application Data/DarkSoulsIII. (I used Pop!_OS while making this guide, but it should be the same or similar for all other distros.) Take a look at this discussion for more details: https://gtm.steamproxy.vip/app/374320/discussions/0/1735463620081727264/.

Each folder inside the DarkSoulsIII folder contains the save data for a different Steam user that has played Dark Souls III on your computer. If you want to figure out which one is yours, follow these steps:

1. Make a backup of all save folders.
   
2. Remove all save folders from the DarkSoulsIII folder.
   
3. Start Dark Souls III and get past the "PRESS ANY BUTTON" prompt.
   
4. Close Dark Souls III and note the name of the new folder inside the DarkSoulsIII folder.
   
5. Restore folders from backup as needed.

Once you know which folder is yours, you can choose to only move that one between computers, or even swap out the DS30000.sl2 file inside the folder to get a different set of save data.