Nintendo's aggressive stance against emulation is well-documented. Recent examples include the $2.4 million settlement with Yuzu emulator developers in March 2024, the October 2024 cessation of Ryujinx development following Nintendo's intervention, and the legal advice preventing a full Steam release of the Gamecube/Wii emulator Dolphin in 2023 due to Nintendo's pressure. The infamous 2023 case against Gary Bowser, who resold devices circumventing Nintendo Switch anti-piracy measures, resulted in a $14.5 million judgment.
A Nintendo patent attorney, Koji Nishiura, recently shed light on the company's strategy at Tokyo eSports Festa 2025. While emulators aren't inherently illegal, Nishiura clarified that their use can become illegal depending on functionality. Specifically, emulators that copy game programs or disable console security measures may infringe on copyright laws, particularly under Japan's Unfair Competition Prevention Act (UCPA). This act, however, limits Nintendo's legal reach outside Japan.
The presentation used the Nintendo DS "R4" card as a case study. This device allowed users to bypass security and run pirated games. Following legal action from Nintendo and other software companies, the R4 was effectively outlawed in Japan in 2009 due to UCPA violations.
Nishiura further highlighted that tools facilitating pirated software downloads within emulators, termed "reach apps" in Japanese law, also violate copyright. Examples include the 3DS's "Freeshop" and the Switch's "Tinfoil."
Nintendo's lawsuit against Yuzu cited one million pirated copies of The Legend of Zelda: Tears of the Kingdom, alleging that Yuzu's Patreon generated $30,000 monthly through features like early access and updates to pirated games.
