Comment by vundercind

There’ve been lawsuits. Anything can happen in court, but emulators are currently about as settled as “legal” as anything. Including commercial ones. Sure, in the US.

Can’t distribute games or other copyrighted software with them, though. Of course that’s still highly likely to get you in trouble. And with the same caveat as anything legal in the US: it’s as legal as your ability to weather a series of failing lawsuits against you.