Since Blizzard added achievements to World of Warcraft back in 2008 over 13 billion have been unlocked. That’s an awful lot of busy bees buzzing around Azeroth.
Lead content designer Cory Stockton revealed at GDC that an average of 8.7 million are unlocked every single day. According to Stockton, achievements in WoW have to follow an established set of rules, two of which are that they shouldn’t reward bad gameplay or power leveling.
“We don’t want players to have the expectation that they think they need to get them,” Stockton said, which can be problematic for some of the time-limited Feats of Strength achievements which reward players for playing WoW during a certain event or time period. “If you missed it, it’s gone forever,” Stockton said. “And it’s really rough to have people stare at that list. So they don’t show up until you actually earn them.”
One of the game’s most popular achievements is “Leeeeeeeeeeeeeroy!” which has been earned by around 11 million players by killing 50 rookery whelps within 15 seconds.
The rarest is “Legendary Pet Brawler,” which has only been earned by one player as of February 2013 and requires you to win 5,000 PvP pet battles.