Emulators are lawful because a small company won its case and went bankrupt doing it

The question is emulation legal is badly posed and therefore has no answer. What is lawful or unlawful is a specific act, and in the case of an emulator the act is this: to write a program that reproduces a console's behaviour you must understand its built-in software, the BIOS. To understand it you must copy it into memory and disassemble it. Those intermediate copies are literal reproductions of a copyrighted work. That was the matter in dispute.

Two cases in 2000

The first is Sony Computer Entertainment v. Connectix. Connectix shipped the Virtual Game Station, a PlayStation emulator for Macintosh computers, and during development copied the console's BIOS repeatedly.

In February 2000 the Ninth Circuit reversed the injunction issued by the lower court. The logic: the intermediate copies were made to reach unprotected functional elements, the interface rather than the expressive content; the resulting product is transformative, since it lets games run on a new platform; and it constitutes legitimate competition rather than substitution.

The second is Sony v. bleem!, which turned on a separate point. In its advertising bleem! used screenshots of Sony's games alongside its own to show that the image on a computer was sharper. The court held comparative screenshots to be fair use. A small ruling with enormous consequences: the entire practice of comparison shots in technology journalism rests on it.

The bill

Sony won neither case on the merits. But Sony had a litigation budget and bleem! did not. The company closed in 2001, ruined by proceedings it was formally winning. That same year Connectix sold the Virtual Game Station to Sony itself, which promptly withdrew the product from sale.

Winning a case and staying in the market are two separate achievements, and the second costs more.

Where the line runs now

From these decisions follows a distinction missing from nearly every argument about emulation. Writing an emulator on the basis of honest reverse engineering is lawful. Distributing a console's BIOS image or game ROMs is not; that is ordinary copyright infringement. Neither legalises the other.

The ground has also shifted since. Nintendo's actions against Switch emulators in 2024 — the suit against Yuzu that ended in a settlement, and the halt of Ryujinx development — were not built on the claim that emulation is unlawful. They were built on circumvention of encryption and distribution of keys, which is section 1201 of the Digital Millennium Copyright Act of 1998, a route that did not exist in its present shape in 1999.

Hence a practical conclusion for anyone who cares about preservation. The legal ground on which emulation and digital archaeology stand today was paid for by a company that no longer exists, and it came about only because Sony went to court with deliberately broad claims. Precedents are rarely made by the people who later get to stand on them.