After nearly a year of debate and deliberation , the Library of Congress (LoC) has granted gamers and preservationists a limited legal method to restore access to games that are rendered unplayable thanks to defunct, abandoned authentication servers.

In new guidelines published today, the Librarian of Congress said that gamers deserve the right to continued access to "local play" on games that they paid for, even if the centralized authentication servers required for that play have been taken down. So if Blizzard, for instance, decides to take down the authentication servers required to verify a new copy of StarCraft II online, players will now be legally allowed to craft a workaround that allows the game to work on their PCs.

"The Register explained that the inability to circumvent the TPM [technological prevention measures] would preclude all gameplay, a significant adverse effect, and that circumvention to restore access would qualify as a noninfringing fair use," the new rules read in part. Under the rules, such authentication servers are considered abandoned when the publisher publicly announces that it has discontinued support or when an unannounced server shutdown has gone on for at least six months.

The LoC placed some important limitations on this new legal right, though. For one, gamers can't legally work to restore online gameplay in titles that required a defunct central server to coordinate such play. Creating third-party matchmaking tools, the LoC argued, would necessarily run afoul of the DMCA's "anti-trafficking provision," which prevents the wide distribution of tools that circumvent DRM and TPM. That means efforts like those to restore online gameplay to the Wii and DS are still illegal under the DMCA.

In addition, gamers are still not allowed to jailbreak a video game console to get around an authentication server check. The LoC was apparently convinced by the Entertainment Software Association's arguments on this score, saying that "such jailbreaking is strongly associated with video game piracy" and should therefore remain legally prohibited.

The LoC did carve out an important exception to the console jailbreaking rules for libraries and archives seeking to preserve games, though. These noncommercial, publicly accessible entities will be allowed "to circumvent TPMs controlling access to video game console software when necessary to maintain a console game in playable form."

In other words, a museum can now legally hack into the firmware of a video game console for the express purpose of ensuring that games remain playable for historical research purposes well into the future. That museum still won't legally be able to create replacement servers to allow for continued online play, though.

The Electronic Frontier Foundation, which argued strongly for these changes, gave qualified approval to the LoC's moves. "We're pleased that the Librarian of Congress granted our petition to give some legal clarity to players, museums, and archives who keep old games running," EFF Senior Staff attorney Mitch Stoltz told Ars Technica. "This exemption will help preserve classic games in a playable form for future generations."

"We're disappointed that the Librarian decided to limit the exemption to games that aren't playable at all without an authentication server," Stoltz continued, "because the heart of many games is online multiplayer mode, and preserving multiplayer play should not have to happen under a legal cloud. This exemption is helpful, but Section 1201 of the Digital Millennium Copyright Act is a disastrous law that's badly in need of reform."

Today's ruling is only guaranteed to be in effect for the next three years, at which point the LoC will have the opportunity to review its rules once again. "It's absurd that we have to spend so much time, every three years, filing and defending these petitions to the copyright office," EFF Legal Director Corynne McSherry said in a statement . "But despite this ridiculous system, we are glad for our victories here, and that basic rights to modify, research, and tinker have been protected.”

The LoC once again denied a related exemption request that sought to allow players to jailbreak game consoles to facilitate the playing of homebrew software. Even if there are legal uses for this kind of jailbreaking, the LoC determined that it should remain illegal because it "continues to be closely associated with video game piracy, thus undermining the value of console software as a secure distribution platform."

Update, 11/2, 2:30p: News about the Librarian's decision broke late last month on October 27. Stan Pierre-Louis, Sr. VP and General Counsel for the game industry trade group Entertainment Software Association, finally offered this response to an Ars request for comment: