“Hunting for distribution rights is essentially detective work,” says Marcin Paczyński, Head of Product at GOG. “Rights can repeatedly change hands or be split up between different parties, and it’s our job to get to the bottom of what happened.”

Preservation of old games involves more than just an extra patch. The journey from dusty unplayable relic to polished, cross-platform installer is a minefield of technical and legal obstacles. The team at Good Old Games remain the industry leaders in the restoration of classic PC games, tasked with reverse engineering code written more than 20 years ago, unraveling knotty licensing issues left behind by defunct development studios, and battling lethargy on the part of skeptical publishers. It’s a thrilling and, at times, gruelling process, but – as the GOG team will testify – it never fails to surprise.

Games generally take one of three paths to the GOG storefront. Newer titles are procured by the company’s Business Development team, while small indie releases are often submitted directly by their development studios (Lords of Xulima and Sunless Sea being two such examples). The vast majority of older titles, however, take the third path; whether they’ve climbed the Community Wishlist or are simply a favourite of GOG’s developers, their distribution rights must be hunted down manually. To that end, the legal team scrutinise the storied history of the game’s original development studio, connecting the dots between mergers, buyouts, and bankruptcies, searching for clues as to which publisher or conglomerate to contact.

“On more than one occasion, our community was also extremely helpful in tracking down classic games,” says Paczyński. “A GOGer might know somebody involved with a release, or try a few of their own leads and share anything that they come up with. There’s actually a community thread on our forums dedicated specifically to this sort of thing, and in the past we’ve been able to follow up on these leads to release the games they requested. It’s always awesome to add a game to GOG.com that’s the product of a combined effort between our team and our community.”

Once a deal has been struck with the new rights holders, the team are – in theory – free to update the game’s ancient source code to run on modern systems. There’s one problem, however: in almost all cases, the original code has been lost or deleted.

“Source and game code is an extremely rare commodity for us,” explains Paczyński. “Older titles have often gone through so many different hands that no one knows who has the original code anymore, or it no longer exists in any usable form.” With source files lost forever, the team’s only recourse is to retrofit retail code taken from a boxed copy of the game.

While publishers are occasionally able to supply an archived build, most classics necessitate a scavenger hunt for the best available edition of the title. These are often found among the GOG crew – “it’s probably not a surprise that many of us are collectors!” adds Paczyński – but it’s not uncommon for the team to trawl the web in search of second-hand copies.

Retail code is far less malleable than source code, and restoring a game to its playable state using only a decades-old installation disk is quite a feat of software engineering. In terms of sheer difficulty, the process might be likened to film restoration using only a VHS recording of a television broadcast, the original negatives having been destroyed.

GOG’s engineers must therefore take a creative approach by using customised emulators and wrappers. “We have a great relationship with the team behind DOSBox,” explains Paczyński. “In the past they’ve helped us create custom setups specifically for a particular release – notable examples include Theme Park and Harvester.” It’s not uncommon for these setups to become extraordinarily complex; the team describe wrapping wrappers around wrappers in a kind of ‘Russian Doll’ approach to emulation.

Sometimes the process of digging through old code in old games leads to surprising discoveries, but easter eggs, such as the hidden message discovered inside Dungeon Keeper, are rare. According to the team’s specialists, these discoveries are not the most appealing thing about the job. What makes GOG’s brand of digital archeology fun, they say, is actually the need for creative experimentation. “You can’t just go through the motions,” explains a GOG engineer. “System compatibility tools are a brilliant go-to, but we’ve had to learn to expect the unexpected.”

When prompted to provide examples, dozens of anecdotes are forthcoming. The restoration of Airline Tycoon, for example, required the team to extract the raw language assets from a multilingual Mac version and port them into the English-only PC build they’d received, thereby providing the same experience for all users. Games which once required switching physical CDs call for novel workarounds to eliminate pointless dialogue prompts. One title completely crashed the team’s Cyrillic systems, and required painstaking patch development.

“There are a few games out there that are only playable with community-made fixes and patches nowadays. In several cases, we’ve been able to get in touch with mod creators to implement their select technical fixes into our releases. Whenever we do this, it’s a must for us to get in touch, get their permission first, and offer a token of appreciation as a thank you – and nearly everyone is just happy to help.”

The complexity of the team’s solutions has a knock-on effect on the testing phase. “We sometimes reverse-engineer parts of a game,” says Paczyński, “but messing with the binaries can produce unexpected results and put a lot of strain on our QA, so we do our best to keep things simple.”

This is not always easy. As a gaming platform, the PC is extremely fragmented – developers must account for a diverse range of chipsets, graphics cards, and operating systems. The effects of this variation are exacerbated by the age and inflexibility of the software being restored. The number of unknown variables spirals, making the testing process gruelling, and the bugs wildly unpredictable.

Incompatible with the power of modern systems, older titles can exhibit bizarre behaviour which only becomes apparent during testing. S.T.A.L.K.E.R and Saints Row 2, for example, would go haywire as the frame-rate skyrocketed, resulting in hilarious physics engine malfunctions and even overheated PCs. Carmageddon was plagued by inexplicable crashes, and its tortuous three-month stint in QA still evokes painful memories among GOG’s testers.

“There’s also a lot of work involved in keeping things working post-release,” says Paczyński. “It’s important for us to never simply fire and forget, and with many of our titles being decades old, we constantly have to pay attention to community feedback and monitor new software and hardware changes to eliminate any problems that can, will, and do, come up.”

The final step is to prepare GOG’s famous ‘game goodies’ – digitised copies of supplementary material including manuals, soundtracks, and original artwork.

This practice originates from the service’s early years as Good Old Games. “We wanted gamers to get all the cool stuff they used to receive with boxed editions,” says Paczyński. “Something to look at, browse through, feel the heft – we wanted to recreate that old feeling of ownership.” Many older games, particularly adventures and RPGs, actually relied on these physical add-ins to complete the experience. Manuals frequently included beautifully detailed maps or reams of lore.

This dedication to authenticity can sometimes pose unexpected challenges. The recently released Forgotten Realms titles of the 1980s and early ‘90s, for example, relied on cardboard ‘code wheels’, a primitive form of copy protection which was integrated into the games’ stories. Rather than treat these wheels like DRM and simply eliminate them completely, the team decided to retain the mechanic for the sake of preserving the original experience. Customers therefore receive a printable copy of the code wheel as well as an electronic on-screen version.

Sourcing these materials entails another round of detective work. In addition to their own personal collections, the team frequently turn to eBay and other online marketplaces. Localised auction sites are often used to track down foreign language editions. The best source, however, is the community; collectors, enthusiasts, and fan site webmasters frequently prove to be invaluable allies during a treasure hunt.

“The community will often send us scans of the manuals, maps, or other bonus content. Sometimes we’ll get whole packages mailed to us in the post as well!” laughs Paczyński. “We’ve actually received bonus items and even physical game versions from places like Canada and Germany.” While the process of buying and digitising all these collectibles can be extremely time-consuming, many members of the team share a sense of responsibility when it comes to this aspect of their work.

“There is a strong element of actually preserving game history – digitising and archiving materials that could disappear at any time. Just talking to our Product team, you can tell that it’s really something of a passion project; they collect tons of materials for games that we haven’t released yet (or materials we can’t get the rights to release). “Just in case”, they say, but years from now when all the online links go down, and the printed pages are faded, a digital copy will at least be kept safe somewhere.”

With the legalities settled, available code patched, game goodies digitised and the whole package rigorously tested, the title is ready for its long-awaited rerelease. In many cases, the game will have been out-of-print for literally decades. This perilous journey out of licensing hell and back to legal sale raises questions about the monetary value of older games, the role of unsanctioned emulation, and the threats posed by DRM.

As we’ve seen, the games medium faces a unique set of challenges when it comes to the preservation of its past. The most obvious example is DRM, even the most archaic forms of which can still be insurmountable by game restorationists. Paczyński recalls the German release of KKND, which used an encrypted executable beyond a simple CD check; the team believe this form of copy protection will be impossible to work around.

Worryingly, however, it seems likely that many of the industry’s recent technological advances – even those regarded as ‘pro-consumer’ – will serve only to make the preservation of today’s games harder in the decades to come. Given the inexorable transition from physical media to cloud-based storage, and the now-ubiquitous requirement for a persistent internet connection, it seems likely that modern games will face a whole new set of challenges. Kyle Orland recently explored some of these issues in a great article for Ars Technica.

Another equally-pressing issue is that of our collective attitude toward older games. When the Internet Archive made over 2,500 MS-DOS games freely available to play in web browsers earlier this year, the news was covered with enthusiasm by dozens of major publications. Undoubtedly, it was a remarkable accomplishment – the IA curators used EmDOSBox, a version of the same emulator powering GOG’s classics and which compiles to JavaScript, to preserve these games in a playable state using open web standards.

But, as Dan Whitehead observed on Eurogamer, our collective indifference to the legality of this move demonstrates some of the issues which confront gaming as it grows up as an art form. “The biggest problem that games face as a commercial medium is that there are no ancillary markets and no reliable revenue streams beyond the initial launch,” writes Whitehead. “Compare it to film. There, the cinema release is just the start of a film’s commercial life […] It has what smartly dressed business people call a ‘long tail’, making money for years to come and helping to fund more movies.”

Services like GOG play a vital role in challenging preconceptions about old games and by making classic games commercially-viable once more. There’s a long way still to go, but the more the industry is aware of the challenges faced in the fight to preserve gaming’s heritage, the better.

“The work we do on classic games here at GOG.com is, first and foremost, born from a passion and love for these experiences,” says Paczyński. “Gaming was alive and kicking well before the digital distribution era, and it’s important for us to preserve these decades of an evolving art form in as authentic and accessible a way as possible.”