Before work began on World of Warcraft: Classic, it was only possible for players to experience the original World of Warcraft by using private servers, which are illegal, often have stability or corruption problems, and generally are very imperfect recreations of the authentic World of Warcraft experience. As much as Blizzard has been aware of the desires of their community, until recently it seemed impossible for them to emulate Classic servers due to the technical hurdles of essentially having to run two massively multiplayer online games side-by-side. A breakthrough was then achieved that made it possible to run Classic servers on the modern architecture of current World of Warcraft servers.
Other decisions were slightly less clear cut. At one point in WoW’s history, there was an 8 debuff limit on any one target. This was later raised to 16, and today there is no debuff limit. Thes change radically changed the balance of classes and strategies players could employ when using these debuffs to overcome content. To preserve that balance—and to avoid the slippery slope of retuning patch 1.12 data to compensate for such modern-era changes—we’re looking at setting a debuff limit of 16 for WoW Classic.
So we asked ourselves, would it still be possible to deliver an authentic classic experience if we took our modern code, with all its back-end improvements and changes, and used it to process the Patch 1.12 game data? While that might seem counterintuitive, this would inherently include classic systems like skill ranks, old quests and terrain, talents, and so on, while later features like Transmog and Achievements would effectively not exist because they were entirely absent from the data. After weeks of R&D, experimentation, and prototyping, we were confident we could deliver the classic WoW content and gameplay without sacrificing the literally millions of hours put in to back-end development over the past 13 years.
Who is Joana? Joana, (AKA Mancow, or FuriousPaul) speedran 1-60 vanilla WoW from 2005 - 2007. I have been server first to level 60 seven times in a row, along with winning Blizzard's "First to level 50" contest they held back in 2006. I also have the fastest time through original vanilla 1-60 WoW in 4 days 20 hours. I have produced a very useful 1-60 horde speed leveling guide along with a 1-60 speedrun video.
To get past these hurdles, the team looked at what we liked (art and data) of what we had and what we didn’t like (the code). We wanted to see if we could utilize classic art assets and data within our modern code and get things to play nicely together. Things didn’t quite work right out of the gate, but with some trial and error, we were able to pull together a proof of concept of how to get things to work together and have something playable. This built our confidence that we could deliver a Blizzard-quality experience with the modern platform.