It looks like fans of Diablo III will have to wait a little longer for the game to hit shelves. Try to act surprised. But really, it’s already been 12 years, what’s a few more months/years/decades?

The thing that makes this delay especially troubling is the amount of work that Blizzard suggests still needs to be done. Typically, when a game is delayed for technical reasons (as opposed to marketing reasons) it is just a matter of fixing glitches and polishing a few things—and that is for games that have had development cycles closer to 2-3 years than the 12 years that Diablo 3 has had. This delay actually sounds like a major overhaul of a few of the game’s core systems.

On Battle.net, Diablo III’s game director Jay Wilson explained the reason for the delay, and highlighted what work still needs to be done.

“While working on Diablo III we’ve been called out for messing around with systems too much, that the game is good as-is and we should just release it. I think that’s a fair argument to make, but I also think it’s incorrect. Our job isn’t just to put out a game, it’s to release the next Diablo game,” Wilson posted. “No one will remember if the game is late, only if it’s great. We trust in our ability to put out a great game, but we’re not quite there yet. In addition to finishing and polishing the content of the game we’re continuing to iterate on some of the core game systems.”

Many of the changes Wilson lists are relatively minor—identifying objects will be quicker and easier (the Scrolls of Identification are gone), and the developer is introducing a dedicated potion button for example. The customization system is also being cleaned up, and things like the “Mystic artisan,” which Wilson claims just wasn’t adding anything, will be removed. That may change in future DLCs, but for now it is gone.

But once you begin to pull the thread, it is hard to stop it from unraveling. Along with the somewhat minor changes above (in the sense that they just need to be reworked in the coding), Blizzard is also reconsidering some of the core systems. The biggest changes will be with the skill and rune systems, but for now Wilson is keeping those under wraps.

Blizzard will also be reworking the strength, dexterity, intellect, and vitality of each character class, and defense, attack, and precision have also been dropped as attributes. These are not just minor tweaks, but fundamentally change the balance of the characters. Some of the display menus will also be changed, including character stats will now be visible in the inventory interface. All of which is going to take time.

Those that played the beta will also notice in the final game that the Cauldron of Jordan and Nephalem Cube have both been removed. The Stone of Recall has also been renamed the Town Portal, which makes the items obsolete.

Considering the game is—or was—scheduled for a Q1 release (Best Buy even announced a February 1 release date, which Blizzard quickly denied), the amount of work that apparently needs to be done is significant. The Q1 release date is almost certainly out of the question now, and there is even a chance that a 2012 release is in jeopardy.

Still, for as frustrating as the delays may be for fans, Wilson is right—people will forget the delays as long as the game is solid. You have to give Blizzard credit for standing by its guns and deciding to make major changes, under what must certainly be incredible pressure to deliver the game. In a day when most developers are happy with releasing a title and issuing patches to fix any issues, it is laudable that Blizzard is waiting until it is happy before releasing the game.

On the other hand, it has been 12 freaking years.

“Our hope is that by embracing our iterative design process in which we question ourselves and our decisions,” Wilson said, “Diablo III won’t just live up to our expectations, but will continue to do so a decade after it’s released.”