One of the biggest challenges to overcome for Wrath of the Lich King Classic is the coding WOTLK Classic Gold. Consolidating all the information of Classic, Wrath of the Lich King and retail World of Warcraft into a one-of-a-kind experience is an arduous process. According to Birmingham it is necessary to import the code to Vanilla World of Warcraft, Burning Crusade, and Wrath of the Lich King and aligning it with both the present Classic and retail World of Warcraft versions.

"We're dealing with six distinct version formats and trying to ensure that changes that occur within one are correctly and appropriately reflected in the version that we release in the future. That's a task we're dealing with by making notes of the changes as well as considering which versions make an ideal sense to use."

According to Birmingham, the games' World of Warcraft maps are some of the most complicated components to convert. "[The World Map] system changed significantly through various patches," Birmingham explained "We designed all of the systems, and changed them later to make them more coherent." The data that comes from the maps from different eras of World of Warcraft are all different and streamlining them was a baffling task.

Additionally, spells have been formatted , reformed and formatted many times over the years and, paradoxically, Zierhut was the person who created most of the spell script formatting for the retail version of World of Warcraft in the past. "And we'll have to do it again!" he lamented.

"Now, we have"the Lich King version that never got updated." Wrath of the Lich King was the first instance of abilities having distinct spell scripts that were attached to various difficulties of spells buy WOTLK Gold, however, the growing complexity of the Warcraft code means they needed to be revised to work with Game Engine.