To form a group, right-click a character and click Invite to Group, or type /invite charactername in the chat window. The health and states of all group members are displayed in a window on the left side of the screen. The group leader is identified by the crown beside their name.
Group leaders can right-click their names to access Loot Options. They can also right-click another player and opt to Remove Player or Make Group Leader. All players can leave the group by right-clicking their name and clicking Leave Group.
If one player in a group enters a dungeon, the other group members will have the option of being moved to their location.