Duriel Necro Strategy

Strategy for the Necromancer
This is a guide for any kind of a ranged necromancer build.

This is possible on any difficulty, but hardest to do it on is in normal because you will NEED Bone Prison for it to work. To do this well, you don't need any kind of mercenary or a summon, but a cold Iron Wolf or Rogue will help your bone prison last longer. What you need to do is just imprison Duriel as soon as you enter the room, so that he is around the middle. He must not be too close to you as his melee attack has a decent range. If you want to, you can cast iron maiden on him so he gets damaged if he attacks the prison, but not recommended as his AI doesn't let him do that, not even on hell difficulty. Once he is in the prison, just teeth/bone spear/bone spirit/range him till he dies, recasting bone prison every few seconds so he doesn't accidentally break it or so it doesn't run out of time. You will need a fair share of mana potions and the fight will take you a total of 1000-1500 mana with a fully synergized bone spirit on hell.

This guide is for a typical (skeleton) Necromancer against Normal-difficulty Duriel.

A Necromancer with at least some summons (and a golem) is perfectly capable of going through Acts I and II without spending a single stat point in the process, since summons are effectively extra life points, are very cheap compared to how much damage they can do, and make it unnecessary for you to get better weaponry and armor. You will probably get to the entrance of Duriel's Lair somewhere around level 21, and if you conserve these points you should have 100 free attribute points. Save these for after your first encounter with Duriel, because you will want to know how to place your attribute points. (You'll probably want to have added 40 points or so into vitality.) The objective is to allow yourself to be defeated in the first engagement and gauge your need for the various attributes, and to get a "sense of proportion". You will actually get around to taking on Duriel at another time.

If you don't have all these extra attribute points, you'll have less flexibility but it does not mean that it will be impossible.

Before you enter Duriel's Lair for the first time, open a Town Portal in the staff chamber. That way you won't need to worry about running right into Duriel upon your return via portal. When the actual battle begins, however, you will want to open a portal up the moment you enter the Lair and then just stay put, going through at a moment's notice.

So try it! Take on Duriel with whatever skills and weaponry you have. Things you should note while fighting it:


 * Duriel has a LOT of life, and has good Defense (avoids your attacks well), so you'll need to hit it hard and hit it a lot of times.
 * Duriel moves much faster than you, his hits stun and chill you (slowing your movement speed), and he can't be stopped in his tracks in any way.
 * The room is very cramped and Duriel can Charge at you if you try to back away, so you stand to gain nothing and lose a lot trying to move around too much.
 * Duriel does a LOT of damage, hits very quickly, and practically always hits, enough to kill anything in 1-3 hits, including you!

The conclusions you should gain from this experience are:


 * There's no point moving around once you're in the Lair
 * There's no point trying to boost Defense or Attack Rating
 * There's no point trying to take it on with a weapon: it does nearly no damage in proportion to what Duriel can do to you
 * Melee weapons are even worse because you'll only get to use them 1-3 times before you're dead
 * There's no good way of getting your items back if you die, so don't put them at risk.

And now, how to defeat Duriel...:

No Need for Items
Additional Defense and Attack Rating won't be of much help. Why? Because although Duriel's stats say that it does 19-25 damage per hit, in battle it'll feel like it's doing around 60-180 damage with every hit as it keeps using a Charge attack and attacks incredibly fast. Defense only reduces the chance you'll be hit, and given Duriel's high Attack Rating your Defense won't come close to compensating. Even a shield that states 28% Chance to Block really only has around 7% chance to block and so isn't very useful either (the key is to stay out of harm's way).

As for attacks, you will want to be using Bone Spear rather than any other weapon, so don't bother with Attack Rating boosters. After all, if you get killed you'll lose your weaponry. This eliminates any need for higher-end items, so you shouldn't need higher Strength or Dexterity.

So don't make getting additional life, cold resist, or defense - for yourself, your mercenary, or your minions - your top priority. None of that will help you for more than a second. You will, however, need to have at least 100 life somehow (perhaps using attribute points) so that you can survive at least one attack and cast Town Portal.

You shouldn't need to be equipped with any items at all! Be self-sufficient on skills alone.

That said, the first-time-around items you should be getting are:


 * A good Wand, preferably one with +10% Faster Cast Rate / +1 to Bone Spear
 * A Zombie Head, preferably one with +2 to Raise Skeleton

You won't be needing potions either, because as was mentioned earlier, if you're using potions you'll die before they take effect (Duriel hits much harder than potions can recover) and using Full Rejuvenation Potion s will be a total waste. Instead, you'll want to be using a Blood Golem for true defense.

Skills
It is advisable that you have at least the following skill points:


 * lvl 1 Clay Golem
 * lvl 1 Blood Golem
 * lvl 1+ Raise Skeleton
 * lvl 3 Skeletal Mage
 * lvl 1 Amplify Damage
 * lvl 1 Iron Maiden
 * lvl 1 Teeth
 * lvl 1 Corpse Explosion
 * lvl 1+ <font color="#8888ff">Bone Spear

All of these are skills that either are prerequisites for other skills or are going to be useful in the long run anyway. This adds up to 11+, when you're on level 21, so you should have around 10 free skill points to add where you find them necessary. The ones that are useful for the fight against Duriel are <font color="#8888ff">Blood Golem and <font color="#8888ff">Iron Maiden, and to a lesser extent <font color="#8888ff">Skeletal Mage , <font color="#8888ff">Raise Skeleton , <font color="#8888ff">Bone Spear.

Familiarize yourself with the effects of <font color="#8888ff">Blood Golem and <font color="#8888ff">Iron Maiden. Iron Maiden returns 200% damage. With 200+ life, a Blood Golem is in this situation twice as useful as a Clay Golem because it has twice as much life as a Clay Golem, with 100+ life, which means that a Duriel under an Iron Maiden curse loses twice as much life killing a Blood Golem as it would killing a Clay Golem, and in boss battles time is everything. The "blood transfer" aspect isn't much of a handicap because if Duriel ever gets to you you're dead in 1–3 seconds anyway. Make sure you can cast Iron Maiden in a split second with near perfect precision - practice with using it on your Blood Golem in your battles in the Tomb of Tal Rasha until you can do it effectively. Practice summoning a new Blood Golem and then casting Iron Maiden right next to it in the same second; get a new mouse if your old one is unreliable; this will come in very useful in the boss battle. The idea is to have a Blood Golem always in the front line and taking the damage

Hotkey your <font color="#8888ff">Blood Golem, <font color="#8888ff">Iron Maiden , and Town Portal buttons right next to each other and practice using them early. The last thing you want is to accidentally select the wrong spell while in battle. If you have <font color="#8888ff">Bone Spear, set it as your primary attack (left click option) instead of a weapon because Bone Spear will always hit, you won't last long enough to run out of mana and you don't want to fight melee anyway.

The skeleton minions are only truly viable the first time you fight Duriel because after that you won't have any corpses to work with. So you'll want to conserve every skeleton mage you have, and you can be sure all your skeleton warriors will die in the first engagement, one hit each. You can use <font color="#8888ff">Unsummon (from the right-click option menu) to get rid of skeleton magi until you're left with all cold and poison magi, which are the types you want (one to slow Duriel down and one to deal damage). Don't bother putting more than 3 points into <font color="#8888ff">Skeleton Mage ; they're a minor contribution at best.

Mercenary
Make sure you have a mercenary with you. It should be one of the following:


 * Non-Cold Rogue with a bow that has <font color="#8888ff">+X Cold Damage
 * Cold Rogue (Casts Ice Bolt on its own)
 * Greiz's Mercenary with a melee weapon that has <font color="#8888ff">+X Cold Damage

Preferably a weapon with a fast attack rate and one with <font color="#8888ff">+X Poison Damage. You can get <font color="#8888ff">+X Cold Damage with a <font color="#888888">Sapphire and you can get <font color="#8888ff">+X Poison Damage with an <font color="#888888">Emerald. The cold damage is irrelevant; however, slowing Duriel is going to be useful considering how fast it is. The poison damage is the most effective of all the gem varieties and damage over time is no problem. The idea is to do as much damage as you can as fast as you can before you get killed, because you certainly can't do much to avoid damage. Don't bother equipping anything expensive for your mercenary outside of a good weapon - even an armor with 100 defense will be of little use.

Fighting Duriel, Part I
There are two phases to fighting Duriel. In Phase 1, you are going in for the first time (or, second time after the first visit mentioned earlier), complete with your mercenary, your Blood Golem, three Skeletal Magi and at least one Skeleton, and with your items. Before you enter the Lair, you open up a Town Portal. (If you want to, move away slightly from your starting place, by no more than a few meters, so you aren't with your back to a wall, but make sure you are never the closest to Duriel.) Your minions should take up positions on your corner of the room.

The moment Duriel appears in vision - which will be in 1–3 seconds - cast <font color="#8888ff">Iron Maiden at it, "leading" the casting of the curse so that Duriel is affected by it. You will need to re-cast Iron Maiden every dozen seconds or so - DON'T forget to re-cast it! While your forces are all attacking Duriel, your Skeletons and Blood Golem will close with the enemy. Duriel will take out any non-mage Skeletons you have in 2–5 seconds and then proceed to eliminate your Blood Golem in 1–3 seconds more. During this time you can add your <font color="#8888ff">Bone Spear s to the fray if you feel you are ready. However, your top priority is to summon a Blood Golem the instant the previous one dies so that you always have a Blood Golem on the field and keeping Duriel away from you. Every time you repeat the cycle - you summon a Blood Golem and Duriel kills it - Iron Maiden shaves 400 life off of the 4000-life Duriel. This cycle will happen roughly every 2 seconds, so you will really need to pay attention to perpetuating the cycle as opposed to attacking Duriel with Bone Spear, which does roughly 50-80 damage over the course of the cycle. Keep things in perspective - keeping a Blood Golem out on the field is far more damaging to Duriel than constantly streaming Bone Spears at it. You will need to use your mana potions if you don't want to end up mana-drained.

However, summoning Blood Golems is not a perfect art, and so in 2-4 Blood Golems Duriel will have wiped out everything else you have or otherwise have gotten to you. At that point you will only have 1–3 seconds of life left, so make the most of it with a final Iron Maiden (your Bone Spears will be slower because you'll be alternatively stunned and chilled whenever Duriel attacks). Then you'll die. If you haven't shaved off at least 1/5 of Duriel's HP by this time, you're doing something wrong.

The good thing about fighting Duriel is that the good guy (you) gets to come back to life and continue on.

Fighting Duriel, Part II
In Phase II, you rush back through Lut Gholein, summoning a <font color="#8888ff">Blood Golem and resurrecting your Mercenary in the process before rushing back through the Town Portal. If you had cast the Town Portal in the True Tomb of Tal Rasha, you will be able to back-track and summon more minions from the corpses. Remember, a few cold skeleton mages will buy you lots of valuable time against Duriel.

If you had cast the Town Portal from Duriel's Lair, you will enter back in Duriel's Lair. The first order of business upon re-entry is always to open up a new Town Portal, because if you don't, you won't be able to continue the fight after you're defeated. The next thing to do is to cast <font color="#8888ff">Iron Maiden on Duriel. The third would be to summon a second Blood Golem, since by this time 2–3 seconds will have elapsed and your first Blood Golem would be pretty much dead. In between the periodic summoning of the Blood Golem, do try to get in a few more hits with your <font color="#8888ff">Bone Spear. You won't survive for more than 20 seconds but if you are able to get Duriel to slay 2-3 Blood Golems - and don't forget to cast Iron Maiden - that's another 800-1200 shaved off its life. Then you'll die again.

And again. And again. (...)

And then, Duriel will die. It may take as many as ten rounds to accomplish the feat, but the rewards are very much worth it.

After you've defeated Duriel, make looting, getting to Tyrael, and "Save and Exit Game" your first order of the day to ensure that you won't have to go through all that again.

Conclusion
On the Normal difficulty, Duriel can be killed with ease. Despite that this page describes Duriel as a difficult boss, it's actually a pretty easy and manageable battle on Normal (albeit not the same on Nightmare and Hell). And the above guide is probably more accurate if describing Duriel on Nightmare/Hell.

The following skills on bold are required, others are just a prerequisite:
 * lvl 1 <font color="#8888ff">Clay Golem
 * lvl 1 <font color="#8888ff">Blood Golem 
 * lvl 1 <font color="#8888ff">Iron Golem (optional)
 * lvl 1+ <font color="#8888ff">Raise Skeleton (preferably 9 or 10, with or without a wand or head)
 * lvl 3 <font color="#8888ff">Skeletal Mage 
 * lvl 1 <font color="#8888ff">Amplify Damage
 * lvl 1 <font color="#8888ff">Iron Maiden 
 * lvl 1 <font color="#8888ff">Teeth
 * lvl 1 <font color="#8888ff">Corpse Explosion
 * lvl 1+ <font color="#8888ff">Bone Spear 

The following strategy will be used
 * Summon an iron golem and all of your skeleton. Obviously, bring a hireling, the Mercenary is a good choice for his durability. Also bring tons of Health Potions, and they're not for you, it's for your hireling.
 * Make your way to the entrance of Tal Rasha's chamber, replacing any non-poison/ice magi that follows you (use Unsummon on Fire and Lightning magi and summon new ones) along the way.
 * As stated above, hotkey the Blood Golem, Iron Maiden, and Summon Town Portal so you have an indirect attack and an escape.
 * Select the Town Portal spell and go in the Chamber. As soon as you enter, create the portal (just in case), cast Iron Maiden on Duriel and move away and then create a new Town Portal. Just let your summons and hirelings do all of the work while you spam Bone Spear and heal your mercenary/rogue once the health goes yellow.
 * Again, as stated above, cast Iron Maiden and summon Blood Golem, repeat when the Golem dies, Iron Maiden expires, or both.
 * Skeletons dead? Hireling dead too? Go through the Town Portal, resurrect your hireling and go back to the Chamber entrance, summoning skeletons from corpses along the way. Repeat.

It should take 3 visits at most to kill Duriel on Normal

Trivia
Bone prison and bone wall can save you from getting killed, giving you a chance to cast a Town Portal.