Note: This requires a hacked 3DS with custom firmware (Boot9Strap + Luma3DS).

Method 1 – Install official eShop CIAs
If you already own the official ACA Neo Geo releases, you can dump them (using GodMode9) or find your purchased CIAs. These run flawlessly but cost money per title.

Method 2 – Inject Neo Geo ROMs into a CIA

Method 3 – Use RetroArch with a Neo Geo core
Install RetroArch’s 3DS CIA, then load the fbneo or mame2003_plus core. Place your Neo Geo ROMs + BIOS on the SD card. While not a single-icon solution, it handles a full library without per-game injection.

In simple terms:

A “Neo Geo 3DS CIA” usually refers to one of two things:

Let’s address the elephant in the room.

This article is intended for educational purposes and for users who own original Neo Geo cartridges or digital licenses and wish to consolidate their library. That said, the reality of the scene is that most “Neo Geo 3DS CIA” downloads circulating on forums and archives are indeed pirated copies.

For decades, SNK’s Neo Geo has stood as a titan of arcade gaming. Titles like Metal Slug, King of Fighters ’98, Samurai Shodown, and Garou: Mark of the Wolves defined a generation of 2D fighters and run-and-gun action. But owning original Neo Geo hardware (an AES or MVS) is an expensive commitment, and official ports vary by console.

Enter the modded Nintendo 3DS – a surprisingly capable Neo Geo machine when you leverage CIAs (the installation file format for custom firmware 3DS systems).

For the hardcore collector, this is the gold standard. You install the RetroArch 3DS CIA (usually the stable version with cores). Then, you place your Neo Geo ROMs (.zip format) and the neogeo.zip BIOS on your SD card.