One of the striking things about Blizzard, the superstar developer behind some of gaming’s biggest hits, including World of Warcraft, Diablo and Starcraft, is how little it actually does.

That’s not to say the company’s employees aren’t constantly at work, although the Kendo lessons taking place on the lawn outside its headquarters in Irvine, California, on the sunny spring day I visit could give that impression.

The HQ is a hive of industry, even if most of that industry is hidden behind doors marked Secret: No Visitors. But that list of smash hits above constitutes fully half of the franchises Blizzard is developing. Those three are stalwarts at the company: World of Warcraft is celebrating its 10th anniversary, Starcraft II is six years old and two expansion packs into its life, and Diablo III is enjoying a second wind as an acclaimed couch co-op game four years after it first launched.

A statue of an orc riding a dire wolf commands the centre of Blizzard’s HQ. Photograph: Alex Hern/The Guardian

By contrast, Blizzard’s other three games are newbies on the scene. Hearthstone launched in 2014; Heroes of the Storm, a MOBA (“multiplayer online battle arena”, an ugly acronym coined to describe a relatively new genre of team-based tactical games) drawing in characters from across Blizzard’s other games, launched last year; and Overwatch, the company’s first fully new intellectual property since StarCraft launched in 1998, is a team-based first-person shooter with Valve software’s mega-hit Team Fortress 2 firmly in its crosshairs.

Focused products with consistent quality

That focus means that Blizzard is a very different beast from almost every other company in its industry. Even its biggest direct competitor, Valve – a company notorious for its own intense work ethic and with a similarly focused pool of titles – still has a raft of side projects and other distractions, from the Steam gaming platform to the Vive, its VR headset co-created with Taiwan’s HTC.

To find the best comparator for Blizzard you have to look outside gaming to track down another company noted for its focused product line, polished offerings and consistent quality. Blizzard is the Apple of games.

There’s another angle to that comparison, though. For all that Apple and Blizzard both pride themselves on their innovation, the companies are notorious for coming late to almost everything they do. That’s not to say that they aren’t enormously influential, and often successful in overturning conventional wisdom and reinventing the markets they enter, but Blizzard no more invented the concept of the MMORPG any more than Apple invented the idea of an MP3 player.

Blizzard’s best hits take genres and concepts that previously existed, and relentlessly refine them, sanding the rough edges off the concepts and trimming excess fat until they emerge sleek, accessible – and, inevitably, extremely popular.

Reinventing Blizzard’s audience

If Blizzard is gaming’s Apple, then, Hearthstone looks set to be its iPhone: the hit product that comes along and upends its business model, reinvents its audience, and makes it a heck of lot of money.

And just like the iPhone, Hearthstone owes a huge debt to what came before it. The most obvious inspiration is the venerable physical card game Magic: the Gathering Magic has a very similar setup: players summon and control minions, which take turns whacking each other and the player characters themselves in an attempt to kill the opponent before they kill you.

Magic is an obvious starting place for any collectible card game to build off: designed by Richard Garfield in 1993, it singlehandedly created the genre, and although other, better games have been produced since (such as Garfield’s follow-up, Netrunner), Magic remains the most popular one in the world.

Magic, The Gathering cards. Photograph: Sarah Lee/The Guardian

That let Blizzard build a game which would immediately be accessible to any one of Magic’s 20 million players – an important advantage, because at the time of Hearthstone’s launch, card games hadn’t made much of an impact in the digital space. You can show almost any gamer a first-person shooter and expect them to be able to pick it up in seconds, but that sort of baseline literacy didn’t exist for Hearthstone’s genre.

Inspired by World of Warcraft

You won’t hear about it from Blizzard’s designers, but there’s also another inspiration for Hearthstone: the World of Warcraft trading card game, which ran from 2005 to 2013. Mechanically, the game was very similar to Hearthstone as it stands today, albeit vastly more fiddly to play. (Part of the reason for consigning it to the memory hole may be the fact that it conflicts with the official story for the game’s origin: that two designers, left alone due to “crunch” overtime on Starcraft II, hammered out the entire game in three weeks.)

The World of Warcraft trading card game wouldn’t have happened without Magic and, directly or indirectly, Hearthstone also draws a lot of its DNA from the seminal game. That DNA has laid the groundwork for the future of Hearthstone from day one. And that planning is paying off for Blizzard this spring, with the introduction of “rotation” to Hearthstone.

In any card game with a growing pool of cards, eventually the number of cards which can be played becomes unmanageably big. That keeps new players out, because the burden of building a playable collection is huge; it makes the game harder and more about rote memorisation, because being able to predict what your opponent will do is tricky; and it presents logistical challenges for the publisher, either having to keep physical cards in print indefinitely, or having to manage an increasingly complex digital storefront to enable players to buy what they want.

Of course, there’s also a more commercial angle: the developer of a collectible card game wants players to keep buying new cards, but they can only do that if the new cards are sufficiently interesting and useful to replace old ones. That very quickly results in a concept known as “power creep”, where a never-ending arms race destroys the balance of the game.

Keeping it simple

So Magic, in 1995, introduced the concept of rotation. Long-term players could still use their entire collections (or nearly all of them, at least – some cards were banned for being over-powerful to the point of being broken) in “Type 1”, eventually renamed Vintage, but new players were encouraged into “Type 2”, now called Standard, where only the newest cards were allowed.

It was always clear that Hearthstone was going to have to tackle the same problems as Magic did, but when Blizzard announced that rotation was coming, the move was almost surprising purely for the extent to which it followed the pre-set playbook. Like Magic and other paper card games, Hearthstone’s rotation sees two older packs being moved out of the Standard game each year, keeping the size of the main playing pool steady at around 700 cards.

Rotation came earlier than some had expected, leaving the Hearthstone card pool small compared with its predecessors – a choice that executive producer Hamilton Chu says came about from a desire to keep everything about the game streamlined. “We really do put a high value on that sense of simplicity … We wanted it to easily fit on one screen, and if someone asks a friend ‘argh, what am I supposed to buy’, it should be a very simple answer. So we really did want to keep that experience good.”

A screenshot of the video explaining the launch of standard and wild formats. Photograph: Blizzard

But other than that, rotation was achieved through a very old-fashioned method. There were no fancy digital shenanigans, just one set of virtual packs being virtually taken out of print as another hit the virtual presses. That decision was not made without much consideration, Chu says – though he declines to go into further detail, for fear that talking about paths not taken could lead to players trying to second-guess the developer.

When I asked Chu if there was a conscious decision to keep Hearthstone grounded in the physical world, though he said that if anything, the team had been fighting to ensure the opposite. “We had to really be very conscious to keep telling ourselves this is a digital game, because there just weren’t a lot of digital card games like this. At least by percentile our experience was vastly in the physical world, so it would have been very easy to stay there.

“In a sense I’m happy that you’re asking this question, because I think it means you’re taking a bunch of what we do for granted, in the good way.” He went on to list a number of cards which would be borderline impossible to do in a physical setting. “Arcane Missiles would just be horrific to do, let alone like Piloted Shredder. You’d have to have some big table and then every time we added some content we’d have to errata the table for you. Cards like Ysera would be a lot more complicated, and doing all the things that we do with tokens would be a lot more complicated, things like Thoughtsteal, where we’re copying cards around… it’s cool, it’s cool that you’ve forgotten all that, because that means it feels very natural.”

Even building Hearthstone as a card game was itself something the team questioned initially.

“For a long time, Hearthstone wasn’t a card game. Because of this thing I’m talking about, we said to ourselves, ‘It doesn’t need to be a card game! Card game is for the physical world, where you have pieces of paper that you cut out. We can be more than that.’

“But after a lot of experimentation, there’s a lot of power in being a card game. People know what cards are, people know what a hand of cards is, people know what shuffling cards is, people know what draw and discard is. And if you go with any other metaphor, you’ve got to explain that.

“And maybe it’s not hard to explain, like, ‘draw a stone from your pouch of stones’ or whatever, like, it’s not the end of the world. But you’ve still gotta teach that. Whereas if you say ‘draw a card’, everybody knows what that means, because of their past history with card games but also just some of that tactile understanding of how the game works.”

Long-term thinking

In what is typical for Blizzard, the development of Hearthstone was a long process, perhaps belied by the simplicity of the finished product. But once Standard and Wild are implemented, in a move that Chu says is “the biggest change to the game since launch”, that’ll be it for major changes to Hearthstone for a good long while. From here on out, it’s up to the team to shepherd the game and its community to the highs of Blizzard’s previous successes.

“One thing we say is that Blizzard has this habit of making games that go on for a long time,” Chu says. “WoW just hit its 10th anniversary, Diablo hit its 20th, so there’s this pretty high bar that’s been set, and we certainly don’t want to be, like, the one that let the rest of the team down.

“Blizzard’s been able to be successful that way because there’s been this very long-term thinking. And we try to make decisions that will keep the game viable for that long, and will keep players enjoying the game for that long.”

Overwatch launch planned for May

Tracer, from Overwatch, strikes a pose in a statue at Blizzard’s HQ. Photograph: Alex Hern/The Guardian

And for Blizzard as a whole, it’s not resting. Since Hearthstone was released, it has launched another major franchise, Heroes of the Storm, and is preparing Overwatch for release in May. Both games represent a new ground for Blizzard, with the company foregrounding its top-tier professional multiplayer play like never before. While Starcraft and World of Warcraft each have intensely popular competitive gameplay modes (particularly in Korea, where Starcraft and its sequel are practically the national sport), it took Hearthstone for Blizzard to try releasing a game that was purely competitive.

It seems to have worked. If Blizzard really is gaming’s Apple, and Hearthstone its iPhone, then Overwatch and Heroes of the Storm are… what? Hopefully the iPads of the metaphor, and not the Apple Watches. But either way, the future of the company looks like it could be heavily influenced by its smallest game.

• Alex Hern attended a press event in Los Angeles, with travel and accommodation costs met by Blizzard.