An open world, also known as a persistent world, as opposed to a group instance, is all of the explorable zones on the world map that continue to exist and change even after a user has exited it, and is open to all players. Open world allows players to meet and interact while exploring and participating in various activities like dynamic events. Guild Wars 2 employs multiple identical worlds (game servers), and players within the same server region (North America, Europe, or China) populate the same open world zones.
Open world in the Player versus Environment (PvE) game mode is set in the world of Tyria, and is divided into zones, also called "maps". Traveling between zones is possible either through portals that connect neighboring zones, or by using waypoints.
A PvE zone may have multiple identical instances, with new instances created by the server automatically if needed to allocate for more players. Players within the same zone who are in a squad or party can join the specific instance of other party members by right-clicking on another player's icon in the party/squad user interface and selecting "Join in <Zone name>".
Open world in the World versus World game mode functions differently as players are divided into factions according to their home worlds, and can only visit other worlds via guesting or transferring (see World for more details).
- According to The Making of Guild Wars 2 book, the developers created the first zone of the game within Guild Wars Prophecies and modified it to play as a persistent world, prototyping active skills and even dynamic events system using that map.