Diablo III release date
From Diablo Wiki
Diablo III's final release date of May 15, 2012 was announced two months beforehand, on March 15, 2012.. This date came after years of development and numerous delays, which pushed the game from Q4 2011 back to Q1 2012, and finally Q2 2012 when the release came at last.
Though the game took longer than expected, there was never any official date until the official May 15, 2012 date, which was achieved. All previous dates were estimates by retailers or media and were unofficial, though the developers did offer several "release windows" such as "the second half of 2011" that they were aiming for all during the previous year.
As with all hotly-awaited Blizzard games, there were years of news and rumors about when Diablo 3 would finally see the light of day.
- News items related to Diablo 3's release date.
- Screenshot gallery of (incorrect) estimated release dates.
- 1 Blizzard's Leaked Product Schedule
- 2 Estimated Progress
- 3 Diablo 3: Release Date Through The Years
- 4 Diablo 3 Beta Test
- 5 Beta Test Timeline
- 6 Blizzard Games Release Dates
- 7 Diablo 3 Demo
- 8 Release Date Gallery
- 9 Archive
- 10 References
Blizzard's Leaked Product Schedule
The image to the right "leaked" via a Chinese MMORPG site in late 2010. . It's alleged to be an internal Blizzard document from April 2010, listing estimated dates for their upcoming product releases. Diablo 3 was listed for the fourth quarter 2011, a fact that gave many fans a huge burst of excitement, and then eventual dismay when that date was postponed.
Blizzard never explicitly confirmed that this was an official document, but they didn't deny it either and the dates and products listed all checked out over time, though there were delays (of course). Rob Pardo commented on their hopes to release Diablo 3 in 2011 in a February 2011 interview  :
The chart got another excellent piece of supporting evidence in November 2010, when Blizzard confirmed that Titan (named in the chart) was the codename for their unannounced but well-known secret next-gen MMORPG . The project had long since been known about, but the code name "Titan" was brand new news when the chart was released.
The final piece of evidence appeared in February 2011, when Japanese and Brazilian localizations were added to Blizzard's upcoming WoW patch  "WoW Brazil" is listed on the chart for mid-2011, so they seem to be right on schedule for that.
Diablo 3 Expansions
The first Diablo 3 expansion, Reaper of Souls, was teased by Blizzard with a splash screen on August 13, 2013, with official details and confirmation set for August 21st, 2013 at the Gamescom convention.
Prior to the reveal, fans and Blizzard always treated the expansion as a fait accompli, with only the content and date remaining to be determined. This impression was strengthened by the leaked product schedule which showed two expansions planned for release, 18 and 36 months after the initial game.
As usual for Blizzard the initial estimate proved optimistic and the first expansion wasn't announced until 15 months after release. No official release date has yet been offered.
- Unofficial official guess the D3X release date pool, with prizes for the winner.
During Diablo 3's development fans constantly clamored for progress reports. Blizzard offered them regularly, but without any publicly-released dates or percentages. Even more than most game developers, Blizzard hates to give any sort of percent completion, since they so often iterate and reiterate (and de-iterate, some fans complain) and this makes progress hard to quantify with development, testing, and polishing all going on simultaneously.
...The game isn’t being developed in a linear fashion so us saying we’re working on things in Act III doesn’t really mean anything in regards to how much of the game is finished.Since we’re constantly evolving the tools and processes for creating the various assets for the game (and just plain getting better at it), it’s best to have as wide a perspective as possible. Otherwise we’d probably paint ourselves into a corner. All of the work being produced at the end of the game would look far and above better than the stuff that was produced at the beginning, and so we’d probably have to go back and redo a lot of that work.
Almost since the game was announced in June 2008, the developers have said that they were well into content production.  (Meaning that the engine and basic game functions were all locked down and working properly.) Content though, especially in Blizzard titles, is such a huge area of work that experienced Blizzard-watchers expected the content production and balancing would take years. And it has.
Diablo 3: Release Date Through The Years
No official release date was ever offered until the final May 15th date, which was announced on March 15, 2012. All prior estimates were purely release windows and estimates, which are collected below:
- November 2009 - The broadest came in the Activision/Blizzard quarterly shareholders conference call in November 2009 where a Powerpoint presentation slide (right image) pinned it down to 'Next Few Years' 
- November 2009 - Rob Pardo in an interview with Techland. "I think it's safe to say that, yeah, (Diablo 3) is not going to be out next year." (2010) 
- February 2011 - Rob Pardo in an interview with Kotaku when asked if Diablo 3 would be released that year said "We really, really hope so. That’s our goal,” “Our goal is to get there. But you know, at the end of the day, we are going to get it right. That’s more important. We’re going to promise, we’re going to get it out there when it’s awesome. And, we’re crossing our fingers, maybe it will be this year." 
- June 2011 - Paul Sams in an interview with Inside Korea said "With Diablo 3 targeted at being launched this year, we plan on testing the game in the third quarter." 
- September 2011 - A technical glitch on Blizzard's website gave the community a premature look at a statement planned to be published at a later time from Blizzard President Mike Morhaime announcing that Diablo 3 would not be released in 2011 . The title offered a tentative new date:
After quickly taking the statement down Blizzard put it back online later that day, probably realising it was futile to shut the barn doors once the horse had bolted.
- February 10 2012 - During the Activision Blizzard financial conference call, Mike Morhaime announced that the game would now release in Q2 2012 which takes it out of the previously stated "early 2012" release date window. 
Diablo 3 Beta Test
The Diablo 3 Team regularly referred to a future beta test, but did not absolutely confirm it until Blizzcon 2010 . The Diablo 3 Beta test began in early September, 2011, and was initially limited to "Friends & Family" testing. The closed beta began in mid-September 2011 and contained the same content as the Friends and Family testers were testing.
The Diablo 3 beta test consists of the first half of Act One, with some story elements and game features removed. The beta test is largely a tech demo, with little game content open to fan feedback; it is not intended to be a full game balance playtest, like many MMORPGs.
Blizzard beta tests generally last 4-6 months, and Jay Wilson estimated that Diablo 3 would be released about six months after its beta test begins.  This did not happen and the Diablo 3 beta was extended several times as the release date was backed up from late 2011 to Q1 2012 and then finally Q2 2012.
- See the Diablo 3 Beta article for much more on this issue.
Beta Test Timeline
After years of offering release date estimates for various games, most of which they missed, Blizzard has grown quite conservative about offering release dates. They now give only vague release date windows, and never any specific dates or targets unless they are very sure they can meet them.
Hence Starcraft 2 and WoW:Cataclysm did not get release dates until about two months beforehand, when those titles were well into their beta tests and the developer was certain they could make that date. Fans hoped the same would be true of Diablo 3, but as it turned out the game was not ready and thus the beta test ran for months longer than Jay Wilson's rough estimate that the game would be released "about six months" after the beta test began. 
In May 2011 Blizzard confirmed that the Diablo 3 beta should begin in the "third quarter" of 2011 . This meant July 1 - September 30. That is a wide target, but one that they met when the Closed Beta began on 20th September 2010. 
Blizzard Games Release Dates
One commonly-cited release date prediction has been the fact that no Blizzard games have (yet) been released much more than three years after they were first announced.
- Starcraft: Announced spring 1996, released April 1998 (2 years later.)
- Diablo 2: Announced Sept 1997, released June 2000 (2 years, 9 months later.)
- Warcraft 3: Announced Sept 1999, released July 2002 (2 years, 10 months later.)
- World of Warcraft: September 2001, released Nov 2004 (3 years, 1 month later.)
- Starcraft 2: Announced May 2007, released July 2010 (3 years, 2 months later.)
- Diablo 3: Announced June 28, 2008, released May 15, 2012 (3 years, 11 months later.)
The developer is aware of this ever-lengthening cycle and they seem keen to correct it, and have made various comments about not announcing any upcoming projects (such as Titan) until the games are much closer to finished.
Diablo = Late June
Diablo I was released in November 1996, but all of the games in the series since then have shown an affinity for late June:
- Diablo 2 release date: 29th of June 2000
- Diablo 2: Lord of Destruction release date: 29th of June 2001
- Diablo 3 Announced at the WWI in Paris : 28th of June 2008
With this history in mind, many fans were hoping for a June 2011 release, though in retrospect this was clearly never in the cards with Blizzard long-aiming for Q4 2011. (Before slipping nearly to June 2012 and inadvertently continuing the June trend.)
Guess the Release Date
Thousands of fans took a guess at the release date in an unofficial release date prediction pool on Diablo IncGamers. The thread was started up when Diablo 3 was announced in June 2008, and became amusing and painful to view over the years, as hundreds of estimates went weeks, months, and then years by the wayside.
Diablo 3 Demo
Blizzard first confirmed a playable demo back in November 2011 
In January 2012 they expanded on their plans 
- See the Diablo 3 Demo article for more details about playable Diablo 3 demos.
Release Date Gallery
Images related to the Diablo 3 release date.
Past date information, now rendered obsolete by the passage of time but it's hear for posterity.
In Activision/Blizzard financial reports, two games are reported as being released this year: Starcraft II and World of Warcraft: Cataclysm. Diablo 3 was never part of Blizzard's release schedule for 2010.
Starcraft II First
There were some rumors in 2008  that Diablo 3 was further along in the development cycle than Starcraft 2. Blizzard immediately denied that, they always said Starcraft 2 would be released first, and it was, on July 27, 2010. With Diablo 3 still nowhere near beta testing at that point, that's as thorough a rumor debunking as you're ever going to see.
- Release dates are revealed about two months in advance - Blue Forum Post, 1/8/12
- Blizzard does not tell retailers release dates in advance - Blue Forum Post, 1/9/12
- Leaked Release Schedule - MMOGamesite.Com, 2/12/10
- Rob Pardo on Release Date - Kotaku interview, 12/2/11
- Paul Sams on Release Date - Inside Korea , 18/6/11
- Titan Confirmed - Destructoid, 20/12/10
- Localized WoW Confirmed - 21/2/11
- Iterative Design Philosophy - Bashiok, 24/11/09
- Diablo 3 in heavy development - Mike Morhaime, Blizzard, 4/8/08
- Diablo 3 first release schedule - Activision quarterly results call, 5/11/09
- Rob Pardo on release - Techland, 19/11/09
- 2011 Release will not happen Mike Morhaime, Blizzard, 23/9/11
- Diablo3 Release Date Slips Mike Morhaime, Blizzard, 9/2/12
- Beta Confirmed - Christian Lichtner, Blizzard, VG247 Interview, 28/10/10
- Beta Duration - Jay Wilson, Blizzard, 30/10/10
- Beta Duration - Jay Wilson, Blizzard, 30/10/10
- Beta Date Confirmation - Mike Morhaime, 9/5/11
- Beta is Live - Blizzard, 20/10/11
- Diablo 3 Demo - Blizzard, 12/11/11
- Diablo 3 Demo - Blizzard, 6/1/12
- Release Date Rumours - Battleforums, 14/9/08