One of the key uses that has set Nintendo's alarm bells ringing in the past is when an emulator bypasses a console's "technical prevention methods" like encryption, says Nishiura. If an emulator does away with specific security measures like this, it is in breach of Japan’s Unfair Competition Prevention Act and you can expect a takedown to ensue.

Nintendo is famously litigious when it comes to emulators. In March 2024, developers of Nintendo Switch emulator Yuzu were ordered to pay $2.4 million in damages after a court settlement with Nintendo.

"To begin with, are emulators illegal or not," Nishiura asks. "This is a point often debated. While you can't immediately claim that an emulator is illegal in itself, it can becom

An attorney for Nintendo has discussed the company's stance on emulation and what it considers to be illegal, according to Japanese law. Koji Nishiura, patent attorney and deputy general manager of Nintendo's intellectual property department,