Former World of Warcraft lead designer Jeff Kaplan told a Game Developers Conference audience last week that, on average, 16.6 million quests are completed on WOW's North American servers every day.
Between June 2007 and March 2009, some 8.5 billion quests were completed in the region, he said. But although WOW's total number of quests has risen to 7650 with Lich King, Kaplan revealed that the core team of quest designers on the game is just five strong.
"We actually feel like we can't let that team get too big without endangering quality," he said. "We feel like we've got a lot of quest-making gurus at this point, and we like the enegry that they have and the way that they work together."
Kaplan - now working on Blizzard's next, unannounced MMO - was speaking on the subject of "directed gameplay", or the way a game "guides the player towards a fun experience".
This could take several forms, he said, from the yellow arrow that shows players where to go in BioShock to achievements, which he considers one of the most important forms of directed gameplay today.
"I think achievements have now evolved to the point where players buy an Xbox 360 game and look at the achievement list first, and use that to decide how to play the game," Kaplan said.
"I made 750 achievements for WOW and some of them just suck, so I'm a hypocrite," he added.
But Kaplan spent most of his session discussing quests, the form of directed gameplay that he's naturally most familiar with. He spent some time explaining how his team at Blizzard had got them right - but even more confessing to what they'd done wrong.
He was pleased with the exclamation point over quest giver's heads that indicates they have quests available. "Today it's taken for granted... but the hardcore didn't like it," he said. "We felt like discovery and exploration were cool, but they shouldn't be required for the core gameplay experience."
He also encouraged the MMO developers in the audience to copy it. "Just put the exclamation point, why come up with a unique crazy icon? Everyone knows what it is," he argued.
Other triumphs were the move to put summarised information at the top of the quest log for quick reference, and the decision, only gradually arrived at, to load quest rewards in favour of money and experience. These, Kaplan explained, are useful to everybody, unlike loot, and "made questing the smart way to play".
This kind of fine-tuning, he explained, is one of the most important facets of game design. "Tuning is an element of game design that's often overlooked. Tuning is the most important thing," he said.
Kaplan then turned to a long list of the mistakes the WOW team had made in designing quests. "I think you'll find the biggest critics of WOW to be the WOW development team," he noted.
There was the "Christmas tree effect", that presented players with dozens of quests at a time. "The problem with doing this is that we've lost all control as designers to guide the player to a fun experience," he said.
"I'm not saying don't give a player choice, I'm saying be smart about how you give a player that choice," he said. "In [Wrath of the Lich King starter zones] Howling Fjord and Borean Tundra, you'll never have more than seven quests in your log."
He explained that limiting the length of quest text was important - the WOW editor only allows a maximum of 511 characters - but still felt WOW's designers were too literary at times.
"I actually wish that the number was smaller, I wish it would've been 256," he said, before explaining that he feels most videogame designers suffer from "medium envy", and don't realise the storytelling strengths of videogames themselves.
"I'm going to direct this at the Blizzard game designers," Kaplan said, addressing his colleagues at the back of the crowded seminar room. "We need to stop writing the f***ing book in our game, because no-one wants to read it."
Other errors in WOW quest design included poorly-paced quest chains - Kaplan cited The Princess Trapped, a chain that starts at level 30 and lasts for 14 levels, ending with an elite boss - and poor quest flow within a zone, with several quests of the same type grouped together - low-level Dwarf and Gnome zone Loch Modan was his example.
In most of these areas, he felt the game had been improved in recent times, and he held up Lich King's Death Knight starting area as an example of perfect quest flow. But there was one recent mistake Kaplan targeted - vehicle-based "gimmick quests".
"These gimmick quests are more fun for the designer than they are for the player," he confessed. "If it's only fun because of the gimmick, it's probably not fun to begin with."
Kaplan concluded his talk with a lengthy analysis of collection quests, often cited as a vestigial flaw in all MMO design. Kaplan's feeling was that there is nothing inherently wrong with them, just in how they're implemented.
"I don't think that collection quests are broken. I think that, lots of the time, we do a shitty job of making collection quests," he said.
Once again, he said, it came down to tuning - getting creature density, combat pace, travel times, drop rates, and the number of items to be collected just right.
On the last subject, number of items, Kaplan held up his hand to creating WOW's worst offender: a quest that requires players to collect all the pages of a book, pages that drop randomly from enemies across the entirety of one of the game's largest zones, Stranglethorn Vale.
"This is the worst quest in World of Warcraft," Kaplan stated. "I made it. It's The Green Hills of Stranglethorn. It teaches you to use the auction house - or the cancellation page," he joked. "I'm the asshole who wrote this quest. I thought it was going to be a cool economy, but in the end it was just bad."
"You can pull off a collection quest if you give some payoff," Kaplan argued, saying that as silly as it might seem to question why you're collecting pumpkins or gnoll paws, the player was bound to do that, and you had to respect that.
"You never want the player to think that somebody made the game. You want them to only think of themselves in the game," he said.
Summarising, Kaplan instructed his audience to look to great recent examples of open-world game design - his favourites were GTAIV and Burnout Paradise - for inspiration.
"Both of those games feature robust open worlds, but whenever the player reaches for a lifeline, it's there," he said. "GTA limits you to being on one mission at a time, yet the game has a brilliant open world feel.
"This isn't hand-holding. It's more what I refer to as great, directed game design."