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April 11, 2024 | BusinessCopyrightLitigationTechnology

Ninten-don’t: Breaking Down the Yuzu Emulator Lawsuit

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Andrew Ramstad

Associate Attorney

Joseph Ford

Client Coordinator

In recent video game news, gaming giant Nintendo filed and settled a lawsuit against the developers of the popular Nintendo Switch emulator, Yuzu.  This legal battle captures the ongoing conflict between gaming companies and emulator developers, particularly in the realm of copyright infringement and piracy.

What Is an Emulator?

A video game emulator is a piece of hardware or software that replicates functions of a video game console on a different device.  Put simply, emulators effectively recreate the experience of using the original console on a computer or smartphone.  Emulators often include additional features not available in the original games like cheat integration, save states, performance enhancements, and third-party game modifications.

Emulation software itself is not inherently illegal, as shown by the Ninth Circuit Court of Appeals case Sony Computer Entertainment v. Connectix Corporation in 2000.  In Connectix, Sony sued software company, Connectix, for copyright infringement related to its Sony Playstation emulator.  On appeal, the Ninth Circuit held that Connectix’s effective reverse engineering of Playstation’s BIOS (basic input-output system) was not infringing, and instead constituted fair use.  The Court effectively ruled that an emulator which reverse-engineers functional aspects of a game console is not, in and of itself, illegal.

While emulators are not inherently illegal, their obvious uses for playing games which are copied and distributed without permission or pay to the game developer (also called pirated games) still raises significant legal concerns.

Nintendo’s Allegations Against Yuzu

Yuzu is a popular emulator developed by Tropic Haze that enables users to play Nintendo Switch games on platforms like Windows PC and Android devices.  According to the complaint filed in federal court for the District of Rhode Island, Nintendo has robust encryption processes on both its game files (“ROMs”) and on the console itself, meant to prevent unauthorized gameplay or copying.  As just one example of that encryption, each game cartridge encrypts the game’s audio-visual output, rendering it useless without the console’s own proprietary decryption key running at the same time.  Those encryption methods running simultaneously permit the games to be played.

Nintendo claimed that Yuzu circumvented this encryption by using illegally obtained Switch decryption keys, which can be used to play unauthorized copies of Switch games.  In so doing, Nintendo alleged that Yuzu facilitated “piracy at a colossal scale,” and allowed Yuzu users to play “virtually any game made for the Nintendo Switch, all without paying a dime to Nintendo” or any other Switch game developer.  While Yuzu is free to download, Tropic Haze offers exclusive updates and early access features for supported games through Patreon (a website where content creators offer sponsorships in exchange for access to content).

Nintendo sought a permanent injunction against Tropic Haze, alleging that it caused Nintendo irreparable harm by enabling users to illegally decrypt and play Nintendo Switch games without purchasing them.  The complaint cites its recent hit game The Legend of Zelda: Tears of the Kingdom as an example of Yuzu’s piracy facilitation.  Full copies of the game were allegedly available more than one week ahead of the game’s public release date, and during that ten-day period, the game was downloaded by users more than one million times.  Nintendo claims that Yuzu’s Patreon support doubled during this time, suggesting a correlation between the emulator’s popularity and piracy.

Nintendo’s Legal Theory – The Digital Millennium Copyright Act

Nintendo’s primary claim in its Yuzu lawsuit was violation of the Digital Millennium Copyright Act’s (“DMCA”) anti-circumvention and anti-trafficking provisions.  Broadly, the DMCA is the portion of the Copyright Act which provided protections for digital copyrights.  While the DMCA’s section safeguarding websites from user-generated content has gained recent attention, the DMCA also prohibits unauthorized access to digital works, such as the manufacturing or selling of products or services designed to circumvent technological measures controlling access to copyrighted content.  In other words, the DMCA prohibits companies from creating technology designed to get around encryption that protects copyrighted material.

By developing and distributing Yuzu, Tropic Haze allegedly enabled users to bypass the encryption on Nintendo Switch games, allowing them to play unauthorized copies of these games on platforms like PCs and Android devices.  According to Nintendo’s theories, these actions were how Yuzu circumvented and trafficked Nintendo’s copyrighted Switch games and therefore violated the DMCA.

Yuzu Settles

Nintendo sought substantial damages from Yuzu developers, including $2,500 for each violation of the anti-circumvention and anti-trafficking provisions of the DMCA, along with $150,000 for each separate instance of copyright infringement.  Additionally, Nintendo had requested that the court seize and destroy all copies of the Yuzu emulator, along with related software and hardware.

Less than a week after receiving Nintendo’s suit, Tropic Haze and Nintendo reached a settlement in what can only be described as a total victory for Nintendo.  Tropic Haze agreed to pay Nintendo $2.4 million and cease any activities related to the Yuzu emulator.   It was also ordered delete all encryption circumvention tools and copies of Yuzu, and surrender the emulator’s domain to Nintendo.

Implications for Emulator Development

This DMCA strategy is tried-and-true for Nintendo, a company with a reputation for vigorously defending its intellectual property from would-be infringers.  As the complaint itself points out, Nintendo has successfully brought four federal infringement suits on similar theories since 2020.  Further, in May of last year, Nintendo sent a demand letter to game developer Valve, requesting that it stop its plan to host the Dolphin emulator on its popular game distribution platform, Steam.  Nintendo argued that Dolphin’s software, which emulated Nintendo’s Gamecube and Wii consoles, included Wii decryption keys in a similar manner to Yuzu instructing users on how to access Switch’s decryption keys.  Valve agreed, and its plan to host Dolphin on Steam was summarily halted.

While Nintendo has had a string of successes with its DMCA claims, the theory has not yet run up against a developer ready to thoroughly fight the claim in court.  Until one does, it remains unclear if modern emulators could raise a fair use defense like Connectix did 24 years ago, or raise another defense to provide modern emulator developers any breathing room.

Despite Nintendo and other developers’ best efforts, emulation is not going anywhere.  Passionate developers see emulation as the only way to preserve legacy video games, just as older movies are preserved in videotape, DVD, or Blu-Ray format.  Despite the settlement, Yuzu’s codebase is still available on GitHub.   Emulators can and will continue to offer unique gaming experiences, and much to the chagrin of game developers, will also continue to test the bounds of legal emulation and the DMCA as they do so.


The scuffle between Nintendo and Tropic Haze highlights the ongoing tension between gaming companies and emulator developers.  As the gaming industry continues to evolve, navigating the legalities of emulator usage and copyright infringement remains a complex issue for all parties involved.  To learn more, contact the team at Romano Law today.

Contributions to this blog by Danielle Yurkew.


Photo by Erik Mclean on Unsplash
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