As there seems to be a bit of confusion as to how Instances work, I thought I'd whip up a quick guide here.
Firstly there are two kinds of instances; 'Walk-in instances' and 'task instances'.
Walk-in instances are just there, you can go up to them and just walk in. There are no other requirements. All classic dungeons (except DF) have two instance entrances in them and so do most Catacombs zones. Generally speaking the level range for the walk in instances will be the same as for the zone they are in - so for example Muire Tomb instances will be designed for level 10-20 adventurers. One will usually be aimed at the higher end of that range and one to the lower end.
Walk-in instances are really designed for groups of at least 4 people. You can go into them solo, but the XP will not be as good as a task instance solo. The more people in the dungeon, the higher the bonus XP is. Only the people in your group can enter the instance. If someone is not grouped and tries to get in they will enter their own instance. If you leave the instance they will remain for 5 minutes and then despawn, so if someone goes LD for example or you want to train halfway through, you can leave and come back to the same instance as long as you are quick. Otherwise you have to start again with a new instance. Aurulite is only dropped in walk-in dungeons.
Task instances are slightly different. They work in much the same way as the old level 1-20 kill tasks. You talk to a Taskmaster (one next to every bindstone in classic areas and in each capital city) and he gives you a quest in a nearby task dungeon. Each Taskmaster can only give tasks to adventurers between certain levels. If you are too low or too high, he'll tell you which Taskmaster you need to talk to at your level. Only groupleaders can start a task and everyone in the group gets the same task. Once you have the task it's just like the old killtasks, if you die you fail it. Tasks can be 'Kill x number of this monster type', 'Kill the boss in this dungeon' or 'kill everything in this dungeon'. You get a bonus XP award when you complete the task (it's automatic, you don't need to return to the taskmaster) as well as very good XP for each monster you kill.
Task dungeons are only found in classic outdoors zones.
In both types of instance monsters do not repop. There are also bosses in each which drop loot as well as cash.
All instances have a level range that they can adjust between. They'll automatically adjust for the numbers and levels in the party but only between certain limits. When you enter you'll be told how many people of what level the dungeon is instanced for. If you go into a Stonehenge Barrows instance at level 10, things will still be purple to you. If you take your group of 50s into a Nisse's Lair instance, things will still be grey.
Walk-in instances are shown on dungeon maps as red spots. Task instances look like small dungeon entrances on zone maps, but can look like anything when you actually see them - some look like piles of stones, some look like split treetrunks etc.
On Camlann each instance exists only once so if you start an instance, a second group can come into your instance and kill you.
Aurulite can be traded with special merchants in much the same way as DF seals. Aurulite only drops in walk-in instances and will drop in varying amounts depending on the level of the monster. There is no difference between different types of Aurulite, it's just an indication of how big the chunk is. Thus an Aurulite Cluster is 15 bits of Aurulite while an Aurulite chip is 1 bit. It'll display in your inventory by the size of the piece and the total number of bits so if you see '30 Aurulite Clusters' that's 30 total pieces of Aurulite and not 30x15 pieces of Aurulite. The Aurulite merchants are in the main Catacombs city for each realm - Kobold Undercity, Shar Labyrinth and Inconnu Crypt. You can buy items with up to 5 or 6 bonuses on them of which one or two may or may not be PvE only. All item types are on sale - all armour, weapons and jewellery options can be bought with Aurulite and low level stuff generally costs around 6-10 pieces each. If you're allergic to the colour blue though stock up on dye first.
Firstly there are two kinds of instances; 'Walk-in instances' and 'task instances'.
Walk-in instances are just there, you can go up to them and just walk in. There are no other requirements. All classic dungeons (except DF) have two instance entrances in them and so do most Catacombs zones. Generally speaking the level range for the walk in instances will be the same as for the zone they are in - so for example Muire Tomb instances will be designed for level 10-20 adventurers. One will usually be aimed at the higher end of that range and one to the lower end.
Walk-in instances are really designed for groups of at least 4 people. You can go into them solo, but the XP will not be as good as a task instance solo. The more people in the dungeon, the higher the bonus XP is. Only the people in your group can enter the instance. If someone is not grouped and tries to get in they will enter their own instance. If you leave the instance they will remain for 5 minutes and then despawn, so if someone goes LD for example or you want to train halfway through, you can leave and come back to the same instance as long as you are quick. Otherwise you have to start again with a new instance. Aurulite is only dropped in walk-in dungeons.
Task instances are slightly different. They work in much the same way as the old level 1-20 kill tasks. You talk to a Taskmaster (one next to every bindstone in classic areas and in each capital city) and he gives you a quest in a nearby task dungeon. Each Taskmaster can only give tasks to adventurers between certain levels. If you are too low or too high, he'll tell you which Taskmaster you need to talk to at your level. Only groupleaders can start a task and everyone in the group gets the same task. Once you have the task it's just like the old killtasks, if you die you fail it. Tasks can be 'Kill x number of this monster type', 'Kill the boss in this dungeon' or 'kill everything in this dungeon'. You get a bonus XP award when you complete the task (it's automatic, you don't need to return to the taskmaster) as well as very good XP for each monster you kill.
Task dungeons are only found in classic outdoors zones.
In both types of instance monsters do not repop. There are also bosses in each which drop loot as well as cash.
All instances have a level range that they can adjust between. They'll automatically adjust for the numbers and levels in the party but only between certain limits. When you enter you'll be told how many people of what level the dungeon is instanced for. If you go into a Stonehenge Barrows instance at level 10, things will still be purple to you. If you take your group of 50s into a Nisse's Lair instance, things will still be grey.
Walk-in instances are shown on dungeon maps as red spots. Task instances look like small dungeon entrances on zone maps, but can look like anything when you actually see them - some look like piles of stones, some look like split treetrunks etc.
On Camlann each instance exists only once so if you start an instance, a second group can come into your instance and kill you.
Aurulite can be traded with special merchants in much the same way as DF seals. Aurulite only drops in walk-in instances and will drop in varying amounts depending on the level of the monster. There is no difference between different types of Aurulite, it's just an indication of how big the chunk is. Thus an Aurulite Cluster is 15 bits of Aurulite while an Aurulite chip is 1 bit. It'll display in your inventory by the size of the piece and the total number of bits so if you see '30 Aurulite Clusters' that's 30 total pieces of Aurulite and not 30x15 pieces of Aurulite. The Aurulite merchants are in the main Catacombs city for each realm - Kobold Undercity, Shar Labyrinth and Inconnu Crypt. You can buy items with up to 5 or 6 bonuses on them of which one or two may or may not be PvE only. All item types are on sale - all armour, weapons and jewellery options can be bought with Aurulite and low level stuff generally costs around 6-10 pieces each. If you're allergic to the colour blue though stock up on dye first.