Games in the original Guild Wars sequence were released in episodes known as campaigns. Players must purchase an individual campaign in order to access the game elements specific to that campaign; however, all campaigns are linked in one game world. Each campaign is independent of the others, with its own co-operative storyline, campaign-specific skills, and competitive arenas. Players owning different campaigns may still interact in shared areas, including trading for items specific to the campaigns they have not purchased. Players who own two or more campaigns may transport their characters freely from one campaign to the other.

The first campaign, Guild Wars Prophecies (originally named Guild Wars), was released on April 28, 2005. The Prophecies storyline is situated on the continent of Tyria and revolves around the Flameseeker Prophecy, a prophecy made by an ancient dragon.

Prophecies was followed by Guild Wars Factions on April 28, 2006, released exactly a year after Prophecies. Factions is situated on the southern continent of Cantha, a small continent based on Asia, which is separated from the continent of Tyria by a vast ocean. The events of the Factions campaign concern the return from death of a corrupted bodyguard named Shiro Tagachi. Factions features a global persistent war between rival nations, and the notion of guild alliances (see guilds below).

The third campaign, Guild Wars Nightfall, was released on October 27, 2006. Nightfall features the continent of Elona, which is joined to the continent of Tyria across a vast desert. Nightfall introduced heroes, advanced computer-controlled units that can be micro-managed by players, including the ability to customize their skill layout and equipment.

Scrapping their initial plans for a fourth campaign, ArenaNet have released an expansion pack, Guild Wars: Eye of the North, to the previous three campaigns on August 31, 2007. Not being a full campaign, this expansion requires one of the other released campaigns, and is only accessible by player characters at level 10 and above. Eye of the North therefore does not feature new professions or tutorial material, but contains new content for existing characters: new dungeons, a number of new skills, armor, and heroes. It is also intended to be a bridge to the sequel to the Guild Wars series, Guild Wars 2. As a promotion for their online store and Eye of the North, ArenaNet released a "bonus mission pack" to online purchasers; containing playable recreations of four incidents in the history of Tyria, Cantha and Elona which each expand the backstory for one of four major NPC characters.

Accounts

The Guild Wars character selection screen for a single account.A new player must create a Guild Wars account using a unique e-mail address and an access key received from the purchase of the game box or through the online store. Once created, additional keys may be added to the account; these keys can belong to additional campaigns that are linked to the account, or certain purchasable features (such as additional character slots) bought from the online store. Once a key is added to an account it cannot be removed and accounts cannot be merged.

An account is initially set to a specific region depending on the version of the game purchased; Europe, America, Korea, Taiwan or Japan. Players from Europe, America and Korea may freely move between the three regions. Regardless of the account's home region, players in all regions can meet and form parties in international districts (instances of in-game outposts).

A new account has four character slots; each additional full campaign added to the account adds two further character slots. Extra character slots may be purchased from the online store