: System updates, DLC, and eShop-exclusive titles are almost always distributed in .CIA format. Key Differences at a Glance .3DS (ROM) .CIA (Archive) Primary Use Emulation (Citra) Real Hardware (CFW) Installation Not required (Playable as-is) Must be installed via FBI Storage Location Emulator folder / Flashcart 3DS SD Card (Home Menu) Updates/DLC Harder to apply Native support Important Note on Legalities and Safety