Using Leaked Nintendo Source Code Poses Serious Legal Risk to Emulators

This latest alleged Nintendo leak includes the source code for the N64, Wii, and Gamecube, but that doesn't mean emulators can just use it.

A treasure trove of what appears to be Nintendo's source code, internal documentation, game demos, and other private and highly-valued information belonging to the company is circulating online. The materials, which are being distributed on file sharing sites, 4chan, and recently highlighted on the gaming forum Resetera, allegedly includes debug builds for early Pokémon games as well as the source code for the Nintendo 64, Gamecube, and Wii consoles.


Motherboard has viewed some of the files included in this leak, which does appear to show internal Nintendo development documentation, marketing instructions for retail stores, and what appear to be software development kits that would have been provided to game makers at the time. Videos of rare N64 demos from Nintendo’s Spaceworld trade shows are cropping up on YouTube. Nintendo did not respond to a request for comment and we have not confirmed the veracity of the leak, or if the materials were actually obtained by hacking the company as the Resertera thread suggests.

It's always fascinating to see previously unreleased game demos and other internal workings from a secretive company like Nintendo, but as many users noted on online forums in response to the leak, it could be particularly useful in creating and improving emulators. Usually, emulators are created by reverse engineering consoles and games to emulate the hardware so it can run on PCs or other devices that aren't the console itself. It's a painstaking process, and theoretically a leak of internal Nintendo development documentation and source code could make a lot of that work much easier.

The problem is that anyone working on emulation, which is legal but highly scrutinized as it can enable piracy, could seriously endanger their project by using leaked materials from Nintendo.

One group that people have speculated could benefit from the leak is the people who make Dolphin Emulator, which has been working on a PC emulator of the GameCube and Wii. But Lioncache, a contributor to the Dolphin Emulator, told VICE they haven’t seen the leaks and don’t want to.


"Such dumps wouldn't be of use to the project due to it being illegal to obtain and use code contained within said dumps,” they said via Twitter DM. “Using code from dumps like that can taint the project and be active grounds for Nintendo to pursue legal action against it.”

“Having a 16 plus year old emulator project go up in smoke isn't something I'd want to happen. I've already seen a few comments on Reddit saying something along the lines of, ‘Well, why don't you just make use of it but change it up a little before using it’, which, uhh, is a profound lack of perspective,” Lioncache said. “Legally, you generally don't get a second chance about these sorts of things if legal action actually gets taken.”

Tom Dietrich, a Copyright Attorney at The McArthur Law Firm in Los Angeles, told Motherboard in an email that Nintendo would need direct evidence of the leaked code appearing in an emulator to have a strong infringement case. Looking at the leak and using it isn’t enough because reverse engineering code is legal in the U.S.

"But they would need to be careful not to literally copy Nintendo code, as that could create an opening for Nintendo to pursue infringement claims and an injunction to shut Dolphin down,” Dietrich said. “Nintendo almost certainly has the ability to scan Dolphin’s open source software for copied code sections, so it is imperative that—if the Dolphin team were to access the leaked material—they use it for guidance only and avoid actual copying."

If you've been following Dolphin at all, then you already know that it's been making incredible progress. In 2019, its developers estimated that they put in about $10 million worth of work into the project so far. It allows users to share Animal Crossing towns on PC and play Super Mario Galaxy in 4K. We can't say for sure that these recent leaks will not filter through the internet in a way that will ultimately benefit Dolphin Emulator, but at least one of the people working on it has told us that they're not interested, and judging from the progress so far, it doesn't seem like the project even needs the leak.

The recent batch of leaks came in two waves, one on May 1 followed by another one May 2. The second leak included a playable port of a beta version of Garfield Kart Racing for the 3DS.

This also isn’t the first time the company has been targeted by hackers. One year ago, 21-year old security researcher Zammis Clark pleaded guilty to hacking into both Microsoft and Nintendo. Clark used a Virtual Private Network (VPN) to access Nintendo’s internal network where he stole usernames and passwords.

In January, hacker Ryan Hernandez pleaded guilty to hacking Nintendo several times in 2016. Hernandez stole internal documents and code from Nintendo, leaked them online, and bragged about it on Twitter. When the police arrested him, it found child pornography in his possession in a computer folder labeled “Bad Stuff.”