Nintendo's IP manager admits "you can't immediately claim that an emulator is illegal in itself," but "it can become illegal depending on how it's used"

Nintendo's patent attorney and deputy general manager of its intellectual property department, Koji Nishiura, has appeared at a new event to shed some light on the House of Mario's view on emulators and what can make them illegal. 

Before we dive in, it's important to note that patent and copyright laws differ according to what country or state you're in, so if you're unsure, talk to a local lawyer or just err on the side of caution.

As reported by Denfaminicogamer (with translation provided by Automaton), Nishiura was a speaker at Tokyo eSports Festa 2025, which ran from January 10 to 12. 

"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 become illegal depending on how it's used."

I was always told that it was perfectly legal to emulate a game you already own if you bought a legitimate copy, but Nishiura explains that there are many ways an emulator can violate the law.

If an emulator copies part of the system it's mimicking, that can be copyright infringement and, therefore, illegal. If it disables some of the game's built-in security features, it can also be illegal. If an emulator links to places where you can download pirated games then it can also be illegal and is known as a "reach app" in Japanese law. So, even if you own a copy of a game on an old system and simply want to play it on your computer, there are many ways your emulator could get you in trouble.

Regarding security, Nintendo asks that you not use "unauthorized services" to play Wii U games, even though it shut down the console's online servers last year as they might be a "security risk."

Nintendo takes the protection of its copyright very seriously. Palworld is currently embroiled in a lawsuit over alleged patent infringement and hacker Gary Bowser owes Nintendo a third of his earnings until he repays the company for his participation with a group that sold emulation devices that allowed people to play pirated Nintendo games.

While you're here, check out the best Nintendo Switch games you can play right now.