Do you mean "it shouldn't be illegal" as in you wish it was not illegal or as in "it is probably not illegal"? Because in most jurisdictions (including the USA) it is illegal to download a backup ROM of something you own. Regarding making a personal backup, some jurisdictions are more permissive but some do not even allow it.

> Because in most jurisdictions (including the USA) it is illegal to download a backup ROM of something you own.

Not a lawyer but I'm suspicious about that: first of all, I don't think downloading is actually illegal, it's either sharing stuff without license or keeping stuff without license that are generally illegal (which is why viewing movies from an illegal streaming website is legal in most places even though the website owner is clearly doing illegal stuff).

Then, if you have a license and the law in your jurisdiction allows personal backup, I think you'd have the right to actually store the thing, so I don't think you'd be breaking the law here.

As "it is probably not illegal", people always say "use the ROM of games you physically own" when talking about emulators, so I have imagine it would be simply legal.

I think that’s largely meant as some combination of a joke and an indemnification of the person saying it. I think it’s common knowledge that everyone who does this is using a file they downloaded from a site they found through Google.

> people always say "use the ROM of games you physically own”

People also say “No copyright infringement intended” while uploading full movies to YouTube. People, especially when it comes to matters of copyright, typically have very poor understandings of law...

So what would be the correct understanding of the law in this case? That using an emulator is illegal because you cannot own a copy of the games you own?

It varies based on country and jurisdiction, but from an American / European perspective - some parts of the emulation scene are “definitely not legal” (eg, distributing copyrighted ROMs), and most parts of the scene are “It is complicated. Well-informed people have different predictions, but it hasn’t been tested in court, so we don’t know for sure”.

Moon Channel (an actual lawyer) has a fairly clear and concise summary with particular relation to the Dolphin emulator’s attempt to get itself on Steam: https://www.youtube.com/watch?v=wROQUZDCIMI

In by far most jurisdictions it is illegal to share the ROM, it is legal to download it.

You are in the clear if you download it from a ROM site (and own the corresponding cartridge). You are not in the clear if you use filesharing, unless you freeload.

Has anyone ever been prosecuted or even taken to court in the US for downloading a ROM of a game they own? I can't seem to find any examples. I'm aware of Nintendo of America v. Bung Enterprises but that is not against a consumer.