In the context of "Diablo 3 Eternal Collection Nsp," the term usually refers to a dumped or decrypted copy of the game distributed online.
The Switch version offers flexible ways to play with up to : Diablo 3 Eternal Collection - Nintendo Switch - Amazon.com Diablo 3 Eternal Collection Nsp
Warning: Installing unofficial NSPs requires a hacked Nintendo Switch (preferably with Atmosphere CFW) or a PC emulator. Proceed at your own risk and ensure you have a NAND backup. In the context of "Diablo 3 Eternal Collection