An American video game developer and publisher founded on February 8, 1991 under the name Silicon & Synapse by three graduates of UCLA, Michael Morhaime, Allen Adham and Frank Pearce and is currently a subsidiary of American company Activision Blizzard. Based in Irvine, California, the company originally concentrated primarily on the creation of game ports for other studios before beginning development of their own software in 1993 with the development of games like Rock n' Roll Racing and The Lost Vikings. In 1994 the company became Blizzard Entertainment Inc before being acquired by distributor Davidson & Associates and later by Vivendi. Shortly thereafter, Blizzard shipped their breakthrough hit Warcraft: Orcs & Humans. Blizzard went on to create several successful video games, including the Warcraft sequels, StarCraft, and Diablo series, and the MMORPG World of Warcraft. Their most recent projects include World of Warcraft's fourth expansion, Mists of Pandaria, the first expansion of StarCraft II, Heart of the Swarm, and Diablo III.

On July 9, 2008, Activision officially merged with Vivendi Games, culminating in the inclusion of the Blizzard brand name in the title of the resulting holding company, though Blizzard Entertainment remains a separate entity with independent management. Blizzard Entertainment offers events to meet players and to announce games: the BlizzCon in California, United States, and the Blizzard Worldwide Invitational in other countries, such as Paris, France and Seoul, South Korea.

In early 1994 they were acquired by distributor Davidson & Associates for $6.75 million. The same year the company briefly changed its name to Chaos Studios, before finally settling on Blizzard Entertainment after it was discovered that another company with the Chaos name already existed. Shortly thereafter, Blizzard shipped their breakthrough hit Warcraft: Orcs & Humans.

Blizzard has changed hands several times since then: Davidson was acquired along with Sierra On-Line by a company called CUC International in 1996; CUC then merged with a hotel, real-estate, and car-rental franchiser called HFS Corporation to form Cendant in 1997. In 1998 it became apparent that CUC had engaged in accounting fraud for years before the merger; Cendant's stock lost 80% of its value over the next six months in the ensuing widely discussed accounting scandal. The company sold its consumer software operations, Sierra On-line which included Blizzard, to French publisher Havas in 1998, the same year Havas was purchased by Vivendi. Blizzard was part of the Vivendi Games group of Vivendi. In July 2008 Vivendi Games merged with Activision, using Blizzard's name in the resulting company, Activision Blizzard.

In 1996, Blizzard acquired Condor Games, which had been working on the game Diablo for Blizzard at the time. Condor was renamed Blizzard North, and has since developed hit games Diablo, Diablo II, and its expansion pack Diablo II: Lord of Destruction. Blizzard North was located in San Mateo, California; the company originated in Redwood City, California.

Blizzard launched their online gaming service Battle.net in January 1997 with the release of their action-RPG Diablo. In 2002, Blizzard was able to reacquire rights for three of its earlier Silicon & Synapse titles from Interplay Entertainment and re-release them under Game Boy Advance. In 2004, Blizzard opened European offices in the Paris suburb of Vélizy, Yvelines, France, responsible for the European in-game support of World of Warcraft. On November 23, 2004, Blizzard released World of Warcraft, its MMORPG offering. On May 16, 2005, Blizzard announced the acquisition of Swingin' Ape Studios, a video game developer which had been developing StarCraft: Ghost. The company was then merged into Blizzard's other teams after StarCraft: Ghost was 'postponed indefinitely'. On August 1, 2005, Blizzard announced the consolidation of Blizzard North into the headquarters at 131 Theory in UC Irvine's University Research Park in Irvine, California. In 2008, Blizzard moved their headquarters to 16215 Alton Parkway in Irvine, California.

World of Warcraft was the fourth released game set in the fantasy Warcraft universe, which was first introduced by Warcraft: Orcs & Humans in 1994. Blizzard announced World of Warcraft on September 2, 2001. The game was released on November 23, 2004, on the 10th anniversary of the Warcraft franchise.

The first expansion set of the game, The Burning Crusade, was released on January 16, 2007. The second expansion set, Wrath of the Lich King, was released on November 13, 2008. The third expansion set, Cataclysm entered into closed beta testing in late June 2010 and was released to the public on December 7, 2010.

With more than 10 million monthly subscriptions in October 2010, World of Warcraft is currently the world's most-subscribed MMORPG, and holds the Guinness World Record for the most popular MMORPG by subscribers. In April 2008, World of Warcraft was estimated to hold 62 percent of the MMORPG subscription market. In 2008, Blizzard was honoured at the 59th Annual Technology & Engineering Emmy Awards for the creation of World of Warcraft. Mike Morhaime accepted the award.

As the website Gamasutra in February 2012 writes, Blizzard Entertainment will lay off around 600 employees "in order to address the changing needs of our company", as the Blizzard CEO and co-founder Mike Morhaime in a statement said. Blizzard has a location in Austin, Tx.