Groups of characters can form together as parties, enhancing group play and social experience. Parties are available in both PvP and PvE, but are more important to PvP play. The maximum party size is five members and members can be kicked (2 votes are required to effectively kick a player).
Members of the party are visible in the interface along with their profession, level, health and current effects. Party members are shown with blue highlighting when targeted and can be seen as a pale blue dot on the compass. The party shares a chat channel and are able to draw and ping (this is acomplished by holding shift and clicking to ping or clicking and dragging to draw) locations on the compass to communicate information.
If a party member is in another instance or on another world their image is replaced with a black silhouette.
If you wish to go to the world that another party member is in, right click on their portrait and choose Join In, and you will be moved to their world.
Parties by game mode
Parties are not strictly necessary for the open world, but are necessary to join dungeons and other player's personal story instances. A player can also join a squad which is useful for coordination during large events.
Like PvE, players can join parties in WvW. Though it isn't necessary, squads are an important part of coordinating in WvW.
Structured PvP is team versus team, so parties are required. Players can either create parties themselves or hot-join a match and be placed into a team. Some maps in hot-join play do not always have five members in the party.