World of Warcraft (commonly abbreviated as WoW) is a massive multiplayer online role-playing game (MMORPG) developed by Blizzard Entertainment and is the fourth game in the Warcraft series. World of Warcraft is a subscription-based MMORPG that lacks an offline mode. The Warcraft series of games are set in the Warcraft Universe, a fantasy setting introduced by Warcraft: Orcs & Humans in 1994. World of Warcraft itself takes place within the world of Azeroth, four years after the events at the conclusion of Blizzard's previous release, Warcraft III: The Frozen Throne. World of Warcraft's release celebrated the 10th anniversary of the Warcraft franchise.

Although its initial release was hampered by server stability and performance issues, the game became popular and a financial success, becoming the world's leading subscription-based MMORPG. On March 7, 2007, Blizzard announced that the subscriber base for World of Warcraft had reached a new milestone, with 8.5 million players worldwide; there are more than 2 million players in North America, 1.5 million players in Europe, and 3.5 million players in China.

The game has won numerous awards and recognitions, including Gamespot's Game of the Year Award for 2004. The first official World of Warcraft expansion pack, known as The Burning Crusade, was released on January 16, 2007.

There is also a World of Warcraft Board Game published by Fantasy Flight Games and a World of Warcraft Trading Card Game published by Upper Deck Entertainment.

Gameplay

Unlike previous games in the Warcraft series, World of Warcraft is not a real-time strategy game, but is a MMORPG. As with other MMORPGs, such as EverQuest, players control a character avatar within a persistent gameworld, exploring the landscape, fighting monsters, and performing quests on behalf of computer-controlled characters (also called NPCs—non-player characters). The game rewards success through money, items, and experience, which in turn allow players to improve in skill and power. In addition, players may opt to take part in battles against other players, including both duels and fights against player characters allied with an enemy faction.

The majority of the quests during the early and middle stages of gameplay can be completed without the help of other players, particularly if the player is a higher level than what the quest suggests. Other portions of the game, such as dungeons (also called instances), are designed to require other players to work together for success. Dungeons are designed for parties ranging from two to five players, up to a maximum of 40 players for significantly more difficult "raids" (a term originating from EverQuest gameplay). The highest level, most complex dungeons and encounters are designed to take raiding guilds months of playtime and many attempts before they succeed.