Nintendo's aggressive stance against emulation is well-documented. Recent examples include the $2.4 million settlement with Yuzu developers in March 2024, the cessation of Ryujinx development in October 2024 following Nintendo contact, and legal advice preventing a full Steam release of the Gamecube/Wii emulator Dolphin in 2023. The high-profile case against Gary Bowser, resulting in a $14.5 million debt for reselling devices that bypassed Nintendo Switch anti-piracy measures, further highlights this commitment.
A recent presentation by Nintendo's patent attorney, Koji Nishiura, at Tokyo eSports Festa 2025, shed light on their legal strategy. Nishiura clarified that while emulators themselves aren't inherently illegal, their use can become illegal depending on how they function. Specifically, emulators that copy game programs or disable console security measures may infringe on copyright. This hinges largely on Japan's Unfair Competition Prevention Act (UCPA), limiting Nintendo's direct legal action outside Japan.
The presentation used the Nintendo DS "R4" card as a case study. This device allowed users to bypass security and play pirated games, leading to a successful UCPA lawsuit against its manufacturers and resellers, effectively banning its sales in 2009. Nishiura also highlighted "reach apps"—third-party tools facilitating pirated software downloads within emulators—as potential copyright violations, citing examples like 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, linking the emulator's Patreon revenue to this alleged infringement.
