Valve has announced that Bethesda Softworks', Fallout 3, is now available for pre-purchase via Steam. Fallout 3 is set to be available in stores on October 28th.

"We've heard from everyone already using Steam that it is a fantastic online platform for delivering PC games," said Vlatko Andonov, president of Bethesda Softworks. "In addition to the leading edge service, the platform also exposes the game to millions of targeted gamers."

More from the press release after the jump.

Fallout 3 features one of the most realized game worlds ever created. Set more than 200 years following a nuclear war, you can create any kind of character you want and explore the open wastes of Washington, D.C however you choose. Every minute is a fight for survival as you encounter Super Mutants, Ghouls, Raiders, and other dangers of the Wasteland.

"Fallout 3 is one of the most important PC launches of 2008," said Gabe Newell, co-founder and president of Valve. "Last year, we were able to deliver major releases such as Bioshock and Call of Duty 4 to the millions of gamers connected to Steam. With Fallout 3 added to the line up of great titles coming to Steam, this year promises to be an even better holiday season for Steam gamers."

Fallout® 3 will become available on October 28 in North America. Fallout 3 has been rated Mature by the ESRB.  For more information on Fallout 3, visit http://fallout.bethsoft.com and www.prepareforthefuture.com.