Do you know this mod is for, or are you having trouble with a specific error message during extraction?
Look for a README.txt or INSTALL.txt inside the folder. This contains the most accurate, version-specific instructions from the creator. SlayReborn v1.2.rar
You usually need to copy the extracted files into the main directory of the game it's for (e.g., Slay the Spire or a similar title). Do you know this mod is for, or
This usually means the download didn't finish. Delete the file and download it again. SlayReborn v1.2.rar
Right-click the file and select "Extract to SlayReborn v1.2/" . This creates a dedicated folder so files don't clutter your directory.
Since the file ends in .rar , you need a specific utility to "unpack" it.