Blizzard's 2012 casual-centric World of Warcraft expansion, Mists of Pandaria, was a huge boon for the company, lead designer Tom Chilton said at Gamescom this week. "We would have been in bad shape had we not done that," Chilton explained. "People who played Vanilla always say 'if it had stayed the same, I would have the same fun now as I did then.' But that's not true." "Audiences always evolve." The Mists of Pandaria expansion introduces "accessible raiding" and other casual features, with the goal of attracting and holding onto players not as interested in traditional "hardcore" gameplay. Chilton said that the company was working on bringing out "new experiences for the hardcore audience" as well through subsequent expansions. Additionally, Chilton noted that Blizzard was warming to the idea of reconfiguring World of Warcraft as a free-to-play title. "For Blizzard it makes sense [to adopt a free-to-play model] at some point. But a lot of the risk is in that transition," Chilton said. He mentioned that some developers going free-to-play, while experiencing an initial surge in active players, don't necessarily manage to keep that momentum going. "We really don't know what the rate is before people drop off and lose interest," he said.