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 the advice given to Dolphin developers against a full Steam release in 2023 due to Nintendo's legal intervention. The high-profile case against Gary Bowser, resulting in a $14.5 million debt to Nintendo for reselling devices that bypassed the Switch's anti-piracy measures, further highlights this commitment.
Now, a Nintendo patent attorney, Koji Nishiura, has shed light on the company's strategy. Speaking at Tokyo eSports Festa 2025, he clarified that while emulators themselves aren't inherently illegal, their use can become illegal depending on their 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, is limited to Japan, hindering Nintendo's ability to pursue legal action internationally.
The presentation used the Nintendo DS "R4" card as a case study. This device allowed users to bypass the console's security, leading to a successful lawsuit by Nintendo and 50 other software manufacturers, ultimately resulting in the R4's ban in 2009. Nishiura also highlighted the illegality of tools facilitating pirated software downloads within emulators, 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 infringement.
