Instances
When traveling the world, you may see a green shimmering door or a red shimmering door. These doorways mark Instances, which contain missions for you to complete. Green doors indicate an available or current mission, while a red door indicates a mission you do not have or a mission you may not be able to get.
Some Instances are class-specific, while others are attached to group missions. You can only complete class-specific Instances with the required class, and grouping with other classes is not possible. Group Instances let players join together, and anyone can complete the Instance if a group member is on that mission.
If two players are on the same mission and it is a class-specific Instance, both players must decide if they would like to go into the Instance as a pair or if they would like to go into the Instance alone.
Heroic Areas
When you enter a heroic area, purple text and a purple map name appear on-screen. These areas are usually marked with the word Heroic and are particularly dangerous when entered alone. These are open world areas that only battle-hardened groups can survive.
