From the entrance to Rhahk'Zor, you will have to kill a bunch of miners, they aren't elite and they die easily. There will also be a few Defias Overseer, which are elite, but not so tough. There are also a couple of Defias Wizards most of the time.
The main danger to a group for the instance are runners. Try to always pull mobs back to your group, don't rush into them, so that if they run, you have room to finish them off before they bring friends. Best is to have a class with some kind of snare though, such as a Rogue with Crippling Poison, Shaman with Frost Shock, Warrior Hamstring, etc. Make sure you designate a person who will be responsible for either snaring or have a instant damage spell available to finish them off.
You will encounter Rhahk'Zor, your first mini-boss. He is not that tough, as you can pull him solo, if you wait for him to be far away from his 2 guards (two Defias Watchman), aka close to you. He hits reasonably hard but slow, has a lot of health, as any boss should have. This fight should be easy. Rhahk'Zor almost always drops a non-magical two-hander, and rarely a green Axe instead.
Note: Every time you kill a boss, the door he was guarding opens up, and a patrol respawns behind you and heads down towards you. After every boss fight this will happen, and the further you go down in the Deadmines, the bigger the patrols will be. So be on your guard and look behind you every now and then. The patrols are a mix of melee and spellcasters. Try to kill the spellcaster first, as their fireballs hurt a lot.
To the right are goblins and further down the big goblin. I suggest clearing the room where Sneed roams about as much as possible before you pull Sneed, you don't want to get adds during this fight. Pull the Goblins back or through the door to fight them. The Goblins have an annoying ¡°knockdown¡± with their thrown axes (even works on level 60s!). Other than that, they are tough, with plenty of health.
If you have a Paladin with the quest The Test of Righteousness, one of the Goblins should drop the [Whitestone Oak Lumber] piece the Paladin needs.
Sneed is slightly harder than the ogre, because you actually have to kill him twice. First destroy his Shredder (which he occupies) and then kill him. Make sure the party is aware of this and do not run off the moment the Shredder dies. The Shredder can be controlled by the [Gnomish Universal Remote]. Take a moment to look for a chest, either near the door that opened, on the ¡°hill¡± in the middle of the room, or in the back corner as you entered.
Don't forget to loot the [Gnoam Specklesprocket] from the Shredder's corpse. Underground Assault completed!
This room contains smelters that allow miners to smelt their ore into bars, as well as boxes filled with lower level engineering reagents.
Gilnid isn't hard either, the only difference with previous bosses is that there is one goblin that always stays too close to him to be pulled solo. So you have several options: Kill the little goblin fast and then Gilnid. Only your tank should take on Gilnid from the start. Or you could polymorph the goblin during the whole fight, provided you have a mage. Take time to check under the ramp leading down to the room for a chest.
If you are lucky, Gilnid will drop a nice ring.
The Cannon and Mr. Smite
As the gate explodes, Mr. Smite starts shouting orders, and mobs will rush for you (usually two Pirates with a parrot). Once the attack is dealt with enter the docks and fight your way up the boardwalk.
Short Cut: It is possible to jump down to the side of the boardwalk, fight of the ship builders and swim straight round to smites mini island, this how ever gives you the risk of accidentally pulling him when others aren't ready, so be careful!
Your group must be aware that as soon as you get close to that ramp, 2 Assassins appear and attack your group, and as soon as they do so, Mr. Smite rushes down from the ship and engages you as well.
The trick to this fight is that Mr. Smite actually doesn't hurt that much as long as his hit points are high. So it's best to deal with the 2 assassins while your tank keeps Mr. Smite busy. Once both Assassins are either dead or under control (polymorphed), focus on Mr. Smite. Also, try to carry the fight away from the ramp, that way every time Mr. Smite stuns your group and goes to his chest to find a new weapon, you have some time to recover while he runs back to you. This is an important reason that you should kill the two assassins first.
I suggest to save up some mana/rage for the end of the fight, because he increases in damage output twice during the fight, and hits really hard when he is low on HP. So save some mana for the last portion of the fight.
The Pirate Ship and Cookie
Go up the ramp, kill a few pirates and go to the left first, you'll find Cookie, he's easy as long as he does not run off and bring adds. He can drop a blue wand with 22.7 DPS, and the coveted Siamese cat pet. After Cookie has been taken care of, go backwards and this time go right, to the other side of the ship.
Before we proceed I must warn you that on the ship there is not much room and it's quite packed. I suggest you have your puller always pull way back to your group. Tell him to do it carefully, especially when reaching the 2nd floor of wooden boards, on the right-hand side of the ship, because Captain Greenskin roams right above it. It is very easy to agro the captain and cause a party wipe. Try to have someone keep a watch on the Captain for early warning if he does agros. If Captain Greenskin aggros on your puller, have everyone jump off the side of the ship into the water, and swim to the right-hand side of the entry to the deck-area. You might just survive or have a rezzer survive to resurrect the dead.
So if you want to save time, let one puller carefully take mobs down to your group. Once the path is clear and the only thing left on the top deck is Captain Greenskin and his guards, your group can move up and engage him.
Around the perimeter of the cave where the ship is located, additional Pirates and goblins are located. There is no need to kill them, except if you want or need the XP and possible drops.
There is a little trick when you pull too many mobs. Almost at the 2nd highest point of the ship, there is a giant water-wheel. If somebody jump on this, the mobs will evade everything. The good point is that you can save a wipe this way. The bad point is that sometimes the mobs will still hit your characters and you won't be able to hit them. This technique is often seen as an exploit, however its ingame since beta and never been changed so most people say it's legal.
Captain Greenskin isn't that hard himself, the problem is that he has 2 guards, but that should not be a problem for your group; now that you managed Mr. Smite, you know how to deal with such encounters. Just do not move too close to VanCleef¡¯s cabin.
The recommended tactic here is to tank the Captain and polymorph the caster. Kill the Captain first, then the other melee mob, and then the sheeped caster.
Captain Greenskin can make casters happy with a very nice staff, and Hunters with a Harpoon. He can also drop the Belt of the Defias set.
Note: it is not uncommon to pull Greenskin at an inopportune moment and wipe. To prevent this, if you pull Greenskin without meaning to, you can jump on the boat's waterwheel. While on the wheel, the Captain and any mobs who followed him will evade, and eventually reset. At this point, your party can jump down from the wheel, resurrect the dead, and proceed once more. It should be noted that low level characters may need to stand at the far outside edge of the wheel so that the pirates no longer "see" them, at which point they will stop evading and will reset. In addition, the non-elite parrot pets occasionally cross onto the wheel, but these can be dealt with easily.
Edwin Vancleef is waiting for you in his cabin, looking like he is all by himself, but actually as soon as you aggro him, 2 guards will come out of the shadows and attack you. There is a trick to this fight: Kill him first, don't try to kill the guards, just polymorph them if you can.
The thing is, if you kill VanCleef's guards, he respawns more of them. If you take too long to kill VanCleef (at 50% health), he spawns additional guards.
One or three words of advice: Kill him fast, and he will be an easy fight. After VanCleef is dead, deal with the guards and you are safe. Alternative strategy: If you do not have enough DPS for a fast kill, have your tank be on VanCleef, while the rest of the group kills the 1st two guards. Then assist with VanCleef. If he spawns a second set of guards, kill VanCleef then the guards.
Don't forget to loot his [Head of VanCleef], which is needed to finish the main quest of the Deadmines. Also loot an [Unsent Letter], which begins a quest line for your next instance: The Stockade.
[Cape of the Brotherhood] 20%
[Emberstone Staff] 35%
[Gold-Plated Buckler] 39%
[Lavishly Jeweled Ring] 35%
[Smite's Mighty Hammer] 20%
[Taskmaster Axe] 25%
[Cookie's Stirring Rod] 30%