Nintendo's aggressive stance against emulation is well-documented. Recent examples include the $2.4 million settlement with Yuzu 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 2023 case against Gary Bowser, who sold 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 legal strategy at Tokyo eSports Festa 2025. While emulators themselves aren't inherently illegal, Nishiura clarified that their use can become illegal under specific circumstances. Specifically, emulators that copy game programs or disable console security measures may infringe on copyright laws. This is primarily based on Japan's Unfair Competition Prevention Act (UCPA), which limits Nintendo's legal reach internationally.
The presentation cited the Nintendo DS "R4" card as a precedent. This device allowed users to bypass security and play pirated games. Following a lawsuit involving Nintendo and 50 other software companies, the R4 was effectively outlawed in Japan in 2009.
Nishiura also highlighted the illegality of tools facilitating pirated software downloads within emulators. These "reach apps," exemplified by the 3DS's "Freeshop" and the Switch's "Tinfoil," can also violate copyright.
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 exclusive content for pirated games.
