Nintendo Lawyer Lifts the Lid on Approach to Piracy and Emulation

Nintendo’s aggressive stance against emulation is well-documented. The company’s legal actions against emulator developers, like Yuzu and Ryujinx, and its involvement in the prosecution of Gary Bowser, highlight its commitment to protecting its intellectual property. A recent presentation by Nintendo’s patent attorney, Koji Nishiura, at Tokyo eSports Festa 2025, offered further insight into the company’s 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 laws, particularly under Japan's Unfair Competition Prevention Act (UCPA). This law, however, primarily applies within Japan, limiting 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 widespread piracy. Nintendo successfully sued the manufacturers and resellers, resulting in the R4's ban in 2009. Nishiura also emphasized that tools facilitating pirated software downloads within emulators, such as the 3DS Freeshop or Switch's Tinfoil, are also subject to copyright infringement claims.

Nintendo's lawsuit against Yuzu developers cited one million pirated copies of The Legend of Zelda: Tears of the Kingdom, linking the emulator's Patreon revenue to the facilitation of piracy through features like early access and daily updates.