"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

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.

Koji Nishiura, Nintendo's patent attorney, weighs in on the legality of video game emulators.

Nishiura added that if the emulator also disables security measures like encryption, that could also be considered illegal. He said this counts for other methods such as flash carts, citing the use of Nintendo DS flash carts (such as the R4) which bypassed security by imitating a legitimate DS game.

Now, a patent lawyer representing Nintendo has lifted the lid on the company’s approach to piracy and emulation, and discussed how the propagation of emulators could lead to software piracy.

However, when you play the same game on your own PC or phone, using an emulator that Nintendo doesn’t own, would it still be legal? The Sony v. Connectix case created a precedent that makes emulation of video game consoles is legal, including copying its copyrighted BIOS.

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,