Yuzu (Nintendo Switch emulator)
Yuzu, stylised as yuzu, is a Nintendo Switch emulator. Its claim to fame includes being lead by the same staff and developers that manufactured the flagship Nintendo 3DS emulator, Citra. During the 3DS's lifecycle, Citra was held to high regards by the 3DS emulation community.
Launching in 2018, only a year after the Nintendo Switch's release in March 2017, yuzu has been met with controversy, primarily stemming from its availability for a highly recent console, as well as being financially supported via a paid donation system for early-access builds and prioritised support.
Fast forward to 2024, and you'll see yuzu as tremendously capable emulation software, running a large amount of Switch software as well as or better than a real Nintendo Switch console. yuzu is available for PC, Mac, Linux, and Android.
Preliminary[edit | edit source]
As seen in Why The Switch Still Excites, Nintendo's role as a console manufacturer includes a responsibility to create an ecosystem for developers to create and publish video games. Part of this responsibility includes ensuring that third-party developers can trust Nintendo's platforms, like the Nintendo Switch, to uphold the developer's copyright, by ensuring that theft of their intellectual property does not occur.
From the Nintendo Entertainment System in 1985, Nintendo can be seen as the sole saviour of the video game market, previously rife with bootlegged software distribution and lackluster financial security. By moderating the ecosystem and enabling a common ground for consumers to play their games, eliminating the necessity for proprietary hardware for individual games, and implementing technological protection measures (TPMs) to prevent intellectual property theft, developers flocked to Nintendo as a video game platform and publisher. Nintendo solely decides which games are playable on their console via a series of hardware and software protections, protecting developers from the copying and distribution of bootlegged software - unlike any console that came before it. Nintendo originated as a playing card company from the 1800s, but video games are their legacy, especially ensuring their success as a company in the later years of its formation. Nintendo's success is a direct result of combating software pirates, and it should come as no surprise that Nintendo wants to protect itself from the consequences that led to the market original demise.
Games released and published by Nintendo currently are protected with numerous copyright protection measures to this day. The Nintendo Switch's operating, Horizon, is an example of flagship security-grade software, and Nintendo's most expansive and technically complicated OS. For example, to date, Horizon publicly has zero exploitable software vulnerabilities that enable high-severity attacks, such as kernel or TrustZone takeover, both of which can lead to the possibility of software piracy. Nintendo invests heavily in the security of its platform, and is widely known to use its position in the industry to deter and set examples for those who threaten it. Horizon is one of the most secure operating systems of the modern era, but that doesn't mean that the Nintendo Switch itself is iron-clad.
In early 2018, a bootROM exploit for NVIDIA's Tegra X1 APU, known as CVE-2018-6242 (fusee-gelee), was documented and disclosed to NVIDIA, before later being disclosed to the public. As this particular APU is not only used in the Nintendo Switch, but devices such as the Google Pixel C tablet and Nvidia Drive autonomous driving framework, it was necessary to inform NVIDIA of the exploit before the general public to prevent malpractice from bad actors, which could have dire implications. Because a bootROM runs before any piece of Nintendo's code, exploits within it bypass a vast majority of Nintendo's hardware security measures that protect the Nintendo Switch and its software. Fusee-gelee was a monumental discovery for reverse-engineering and documenting the Nintendo Switch.
This allowed further and widespread documentation of the Nintendo Switch, especially useful for emulator development. As it bypasses nearly all of Nintendo's security measures, its existence allows exploiters to obtain copies of their Nintendo Switch console's encryption keys, which are unique to every console, before access to those keys are revoked by the operating system. These keys are used in conjunction with others to descramble (decrypt) internal system data, as well as Nintendo's game data.
End-users can take advantage of this bootROM exploit to dump (copy) data from their Nintendo Switch, which (when used in conjunction with an emulator, like yuzu) allows the user to run copies of Nintendo Switch software without using a Nintendo Switch.
Litigation[edit | edit source]
On its own, using Nintendo Switch games without using the Nintendo Switch may appear to resemble a conflict of interest within Nintendo. In February 2024, Nintendo filed a suit against the company that develops yuzu, Tropic Haze. The suit details and cites violations of Nintendo's copy-rights, as well as seeks damages from the theoretical harm caused by the existence of yuzu.
A full overview of the primary court filing can be found here. Feel free to read along with my comments after opening this link in a new tab.
The rest of this page will have my opinions and documentation of each page. I am not a lawyer, and I do not have information internal to either Nintendo or the yuzu team.
What disappoints me more than anything about this case is the likelihood what the end result of this case may be a settlement - meaning a potential lack of legal clarity.
It's a resounding reminder that written law does not govern our society, but corporations who can pay an infinite amount of legal fees do.
Overview[edit | edit source]
Instead of attacking emulators for being an unfair competitor to their consoles, or being necessarily a pirate machine, Nintendo takes a roundabout argument here.
Regardless of if users purchase a game lawfully, Nintendo primarily argues that said user is still violating their copyright by extracting encryption keys [prod.keys] from the Nintendo Switch, a technological measure protecting Nintendo's intellectual property. Extracting these keys is the only possible way to dump and play back a Nintendo Switch game. Nintendo secondarily argues that all digital copies of its works that are not served directly from the Nintendo eShop are inherently illegal, as Nintendo is the only entity who is legally authorised to create copies of their work. Nintendo further argues that yuzu traffics in widespread copyright violations by directing its users to violate section 1201 of the DMCA en masse. Finally, Nintendo argues that yuzu has no other functional purpose other than trafficking and copyright violation, given that yuzu has no functionality without the user bypassing Nintendo's TPMs, which is itself an illegal action.
Page 1[edit | edit source]
Tropic Haze is the name of the LLC that develops yuzu. It is new to me that yuzu's development team technically operates within a company.
It is notable that Nintendo is a Washington company. However, Tropic Haze is located in Rhode Island, which is where this case was filed as well. In comparison to Washington, Rhode Island is not known for intellectual property rights or technology.
It's awfully annoying how Nintendo asserts what is lawful and unlawful here. They have done the same in other recent cases (a large portion of this page is copied and pasted from past suits). It isn't necessarily incorrect or wrong per-se; it is a persuasive plea for the court to pinpoint exactly where Nintendo is citing pain and damages, and to imply that harmful intent was premeditated. I wish the plaintiff were more impartial and merely claimed that their rights were violated by the defendant, and proceeding to show examples of where, which Nintendo does at the end of the document.
Page 2[edit | edit source]
Nintendo starts to form the basis for its primary argument by detailing Nintendo Switch's security measures by supplying background information.
Page 3[edit | edit source]
Nintendo doesn't cite where bunnei, yuzu's lead developer, asserts that "most" users pirate encryption keys. Their later citation for bunnei's quote makes no mention of the quantity or severity of this issue. To this day, even after litigation, yuzu upholds an anti-piracy stance and enforces it strictly and swiftly. Even a web browser, especially with extensions, can be used primarily to pirate property. Yet, Microsoft or Google are not held responsible for the actions of their users by owners of intellectual property. The reason is because yuzu has limited purpose outside of what Nintendo is deeming inherently illegal use, unlike a web browser.
Page 4[edit | edit source]
Nintendo's lawyers are seemingly focussing on the encryption keys more than the emulator itself. A few months ago, LockpickRCM, software monumental to decrypting data from a Nintendo Switch, was recently eliminated from GitHub following a DMCA takedown request from Nintendo. This has no relation to yuzu itself.
More importantly, Nintendo cites section 1201 of the Digital Millennium Copyright Act, an act that protects copyright holders from tampering and unauthorised access to copyrighted works as a result of tampering with copyright protection measures. DMCA is not necessarily limited to audiovisual works, instead acting as a barrier to reverse engineering as a whole for any embedded device protected by copyright, such as the Nintendo Switch itself. The legality of reverse engineering has implications on sectors wildly outside the scope of a video game emulator, and is often associated with Right to Repair as well; RE work customarily needs to be done to ensure compatibility with repair parts that aren't distributed or manufactured by the OEM. Any kind of ruling or precedent based on Nintendo's claims here will be monumental for many sectors of my personal life, including repairs and homebrew.
Nintendo notes how yuzu is meant to operate primarily on Switch consoles. They continue to raise a point about software licensing, which is valid, but largely untested in court. Software, such as Nintendo Switch video games, are licensed; not sold, to users. This means that video games remain Nintendo's intellectual and physical property, even after you pay them for the license to play it. When games are distributed but not protected by any sort of technological protection measure, it is legal to make backups of software. Nintendo clarifies that the case for yuzu does not fall in this scenario.
Page 5[edit | edit source]
Nintendo mentions how Tears of the Kingdom leaked prior to its official release, but this is wholly unrelated to yuzu. As yuzu is a Nintendo Switch emulator, it was able to play this game prior to release by Nintendo via its control on the Nintendo Switch eShop. However, there is no material limitation disallowing users from pirating video games on a physical Nintendo Switch console, which is required to use yuzu under intended usage. Without user-supplied files and documentation obtained outside of the program, yuzu does not allow users to pirate or play Nintendo Switch games.
Page 6[edit | edit source]
Piracy and cheating are generally the only things Nintendo has been known to ban for on the Nintendo Switch; they explicitly do not ban for the presence of custom firmware alone. It is interesting to see them mention their intent to protect the Nintendo ecosystem from these two specific actions in writing, for the first time.
Nintendo specifies how yuzu aids users in "unlawfully decrypting" and playing Nintendo software.
Nintendo goes on to cite where it seeks restitution with 28 USC 1331, 1338, and 17 USC 106/501/1201/1203, dealing with anti-tamper of copyright-protected systems.
Page 7 - 8[edit | edit source]
Nothing to note.
Page 9 - 11[edit | edit source]
Nintendo explains their presence in the video game market and how important it is to protect work of themselves and of their licensees. It essentially is a reiteration of what I have explained in Why The Switch Still Excites.
However, Nintendo mentions the necessity of retaining control over its copyright of older titles, as they sometimes revisit them and avail them for modern platforms, such as with their former Virtual Console services and Classic console series.
Page 12 - 13[edit | edit source]
Nintendo begins explaining its TPMs in place on the Nintendo Switch and its associated eShop, its online digital marketplace.
Page 14[edit | edit source]
Nintendo mentions yuzu's form of income, in the form of its Patreon page and yuzu Early Access builds.
Nintendo clarifies yuzu's primary use case, by mentioning how yuzu does not support native games for the platforms it has been released on.
Page 15[edit | edit source]
Nintendo takes and skews a quote from bunnei, noting how bunnei is aware that users may pirate external documents necessary for yuzu to function as an emulator. Nintendo notates how yuzu may necessitate violation of the DMCA's anti-tamper clauses on the end-user. Remember that Nintendo is holding bunnei responsible for the actions of their agents (yuzu developers and community staff members) and of yuzu's users.
Nintendo specifies that they released patched versions of its Erista model Switch console specifically in June of 2018. There is also an official number of units that are hackable via fusee-gelee: less than 29 million consoles.