Sammath Gul

The 6-man instance in the Dol Guldur instance cluster. This instance is one of the only 2 places in the world where a Symbol of Celebrimbor drops, which is required to craft level 65 2nd ages. Group make up is important. Due to the dynamics of the bosses and trash pulls, I would highly advise having diverse group. Having only 4 different classes for a run really seems to slow groups down and made trash pulls more difficult.

Trash Pulls

Here is a list of the different mobs you will encounter and their specific tricks. Tips to beating them also included.

BEWARE BONE PILES!!

The randomly scattered bone piles MUST be avoided. If approached, they will spawn nemesis ghosts that take a few minutes to burn down (the ghosts continually summon skeletons until at least three skeletons are present, at which point they stop summoning until they have less than three skeletons this is interruptable, though the induction time is short). They slow down group advancement tremendously. Just leave them alone. Beware sharp corners, and tops of stairs. If no one in your group has done the instance, send out one person to scout moving their camera often to avoid these things. Spending 2-3 minutes extra avoiding these things is easier than spending 5 minutes fighting just one ghost.

Brutes

If you've been in the Treasury or done Blagh and Rung from DN, these guys absorb all the damage being taken by those around them, while taking very little or no direct damage done to them. The key is to focus dps on the add(s) to kill the brute as quickly as possible, then just kill the adds. A Champion really helps when there is more than 1 add, as a champion does "double" damage to the brute with aoes to the adds. A guardian or captain really helps here as well to keep all the aggro off the minstrel. Damage aggro does not help here, since the damage is transferred. (Also, remove corruptions if they are present. This helps as well.)

Sorcerers

Their only special attack is a stun that cannot be interrupted. It's a minor inconvenience really.

Loremasters

They do an induction knockback. It's very important that this be interrupted (due to something further down the list). Have your champion or burglar focus on dpsing the Loremaster first, for this reason.

Summoners

These guys do an uninterruptable summon. The only way to prevent the summon is to mez, stun, fear or start a conjunction on them. Champions, Burglars and Loremasters are very helpful here.

Boss One: Urchir

A fire based unseen or undead. He does frontal aoes with his default melee attack (so stay behind him if you're not the main tank). This guy is easily fervour tanked. He has 2 problematic attacks. The first is "Will you bring doom to your friends, [playername]?". This puts a green eye above the affected character's name. If you get this, run around the alter (around, the top is on fire, don't run through it). The second is "Can you handle the burn, [playername]?". With this, he will launch a distributed damage attack on that player. If alone, that person will die. It's best to have everyone group up around the boss on that (instead of everyone trying to find the person he called out). At 60k hp, he starts setting part of the room on fire. STAY OUT OF THE FIRE! At this point, it's a dps race, and the group should move to stay out of the ever-spreading fire.

Boss Two: Alagossir

A lightning based unseen or undead. Same as the first boss, frontal aoes. He also has a knockback, so stay over 90 degrees from line perpendicular to him and the edge (more simply: stay away from the edge). He does wipe aggro, but with a good tank, it's no problem to keep him off the healers. If you get too far away from him, he will say something about straying too far, if you don't move in closer, he will hit you with a huge damage attack. For phase 1, it's best for everyone to stay close to him. Also of note, is the light adds. They will root you, and give you a higher miss chance. AOE them down for best results.

At 98.8k (half his hp), he switches to phase two. During phase two, he calls forth lightning that blasts the area. Each blast does about 1700 damage in an aoe. Everyone should run to the right wall close to him (but not behind him), and hug that wall. Range dps takes over. Melees can learn the pattern for the lightning and go dps, but the area around the boss is blasted with up to 5 lightning bolts at once (killing nearly anyone up there). During all of this, Guldor Lights will be hovering around, a few aoes will take care of them. I haven't seen them do anything special. Overall, a very straightforward fight. Probably the easiest in the instance.

If your group is interested in speeding up phase two of this fight, the pattern that the lightning follows is very simple, and follows a set cycle (divided into 4 phases). (And thanks to Grampsaz for putting this list together! My edits were slightly clearer names, and shortening to save space.) There is a brief time to melee Alagossir immediately after the four-set cycle ends and during the first diamond set. However, the fan set will begin with multiple blasts of lightning right in front of Alagossir. You have slightly more than enough time to trigger a full fellowship maneuver, then everyone should retreat to the blue-circled areas on the map.

'Diamond' - One blast of lightning will slowly circle the entire room. It will start behind him and to the left and follow the outer wall counter clockwise.

'Fan' - Five blasts of lighting will start at the boss, working their way to the back of the room, spreading from each other more and more as they make their way to the back of the room.

'Two Circles' - Two blasts of lightning will start on the boss, running straight down the middle of the room towards the back wall. At that wall, they split and each one will follow the outer wall back towards the boss.

'Two Circles Reversed' - The opposite of the previous pattern. The two blasts start at the boss working around the room, and then up the center back to the boss.

Boss Three: Gorothul

A sorcerer of Mordor (check out Sauron making his second appearance in lotro!). This fight is a mayhem. The boss needs to be tanked, and interrupted. When ghost sorcerers and loremasters spawn, they must be mezed (they despawn after 30-40 seconds)(loremasters should be first target for mez). The boss does knockbacks which can be interrupted by clobber, addle, etc. The boss also does a fear attack, which will move your character at random for 8-10 seconds (don't be alarmed, just get back to the fight when it wears off). A burg for conjunctions or a captain for oathbreakers, buffs and extra healing is almost a necessity here. A ministrel on a champ tank was nearly impossible. This fight has the hard mode. Please read BOTH descriptions, as you may not want to do hard mode. There are bone piles around the room, but these are not activated when you step on them (see below).

Hard Mode Guide

For hard mode, you must NOT kill any of the Fell Spirits that he spawns. This is not hard. They have 4-5k morale, and are difficult to kill with aoe's accidentally since he absorbs them after they've been out for a bit. The catch is, each time a fell spirit despawns, a bone pile is activated. The room will rapidly begin to fill up with skeletons, so you will need AoE's and aggro skills to keep the skeletons off of the healers and you will have to kill the boss before there become too many skeletons to manage.

The rewards for Hard Mode are that you can advance to boss 4, and you earn additional DG medallions (3 from the quest, and 2 more from the 4th boss).

Rewards - Access to boss 4, 2 Medallion of Dol Guldur, and 3 Medallions of Dol Guldor from the daily quest.

Easy Mode Guide

For easy mode, you MUST KILL at least ONE of the fell spirits that Gorothul spawns. Once one dies, the door to the fourth boss locks, and you'll fail hard mode. If you kill all the ancient fell spirits before they despawn, none of the bone piles will activate. A good strategy is to leave one person tanking and interrupting the boss while any adds are out. Everyone else can kill the adds as soon as they spawn. Also, in this phase of the fight you can kill any lore-masters or sorcerers that are left and they will not respawn.

Boss Four: Demafaer (Hard Mode Only)

This is probably the most fun boss in the instance. The room is divided into 4 quarters, and everyone should be within melee range of the boss. He is immune to damage unless there is a skeleton near him. Fell spirits in two of the corners can be used to keep a constant supply of skeletons on the group. The cool part is that he sets 1/4th of the room on fire to start. The group must move as a unit and stay ahead of the fire (best to stay behind it, actually). After about half his health is down, he sets another 1/4th of the room on fire, so half the room is on fire. It's best to target mark someone that can keep an eye on the fire, and everyone just stays with him.