Check out the Diablo 3 Open Beta Weekend FAQ by Blizzard:
We’re pleased to announce the Diablo III open beta weekend, which offers open access to all players with a valid Battle.net account! Beginning this Friday everyone is invited to log in and help us put the game and servers through their paces in this three day stress test as we march toward the game’s release on May 15. You can begin downloading the Diablo III client right now!
From Friday, April 20 at 12:01 p.m. PDT (noon), until Monday, April 23 at 10:00 a.m. PDT you’ll be able to log in, team up with friends, and play each of the five heroic classes to level 13 as you fight to save the world from the impending demonic invasion.
What steps do I need to take?
Log in or create a Battle.net account at http://www.battle.net
Create your BattleTag™, which is required to play Diablo III (What is BattleTag?)
Download the game client, install, and play between 12:01 p.m. PDT April 20 and 10:00 a.m. PDT April 23
I don’t have a Battle.net account — can I still play?
Absolutely! Just visit http://www.battle.net to create a free Battle.net account. Next, download the client from https://us.battle.net/account/download/index.xml and install it. Create your BattleTag, and then log in to the game using your Battle.net account name (email address) and password to begin slaughtering the demonic hellspawn that dare stand in your way.
Are there any differences for stress test participants versus invited closed beta testers?
Stress test participants will only be able to access the beta between Friday, April 20 at 12:01 p.m. PDT (noon), and Monday, April 23 at 10:00 a.m. PDT. In addition, stress test participants will not have access to post in the beta forums and will not be provided Beta Bucks for use in testing the currency-based auction house.
Can all regions/countries participate?
Due to regional differences and features of the stress test client, Korean players will not be able to partake in the stress test weekend. However, beginning the week of April 23, we will be conducting a separate, invitation-only closed beta test that will give players in Korea a chance to try out the game, along with players in the regions of Taiwan, Hong Kong, and Macau.
What if the service is down/laggy/disconnecting me?
It’s very possible that players connecting to the stress test could experience issues with the service. While not ideal, this is exactly why we’re having a stress test. We want to catch and analyze as many bugs as possible during this stress test period, so that we can try to ensure a smooth launch on May 15.
I’m having an issue, how can I get help?
Due to the limited window of the stress test we encourage you to visit the Technical Support or Mac Technical Support forums if you’re having any issues running the game, and checking the Known Issues list if you’re running into a bug. As a stress test participant you will not be able to post in the beta forums.
What platforms and languages do you support?
For the stress test we’re offering the client in English, French, and German for both Windows and Mac. At release the game will be fully localized into English, Latin American Spanish, Brazilian Portuguese, French, German, European Spanish, Italian, Polish, Korean, and Traditional Chinese for Windows, and English, French, and German for Mac.
I’m an invited closed beta tester, what happens after the stress test weekend ends?
As an invited closed beta tester you’ll continue to have access until the beta ends on May 1.