Guide to defeating doppelganger

General advice
The doppelganger will have the same skills you equip. The key to winning the battle is to bring skills that you can use more intelligently than it can.

The doppelganger has a 12 in every attribute.

Hexes, enchantments, stances, and weapon skills that do damage to your opponent when it attacks can be useful if you use them and then do not attack yourself.

The doppelganger will use a melee weapon when in melee range and a ranged weapon when not in melee range. This prevents kiting, but does mean that if you're in melee range and use a ranged weapon, the doppelganger will use a melee weapon, and will be unable to use ranged weapon skills.

The doppelganger's weapon will not have any special mods. If you bring skills that trigger on a particular type of damage and use a weapon mod to make your weapon do that type of damage, the doppelganger will not have the same type of weapon and will be unable to take advantage of the skills.

The doppelganger will have no pet, even if you have one, and will be unable to take advantage of pet skills.

If you bring useless buffs and do not use them yourself, the doppelganger will sometimes waste time and energy casting them. This can be particularly useful for ranger or ritualist spirits with long casting times. The doppelganger is especially fond of spamming Lively Was Naomei as often as possible.

You can cast enchantments before stepping on the third stone to start the cut scene, and still have them on you once the battle starts. This saves casting time and prevents the doppelganger from interrupting them.

The doppelganger generally will not dodge, but you can if you keep your distance. Dodging means you have to go a while without attacking, but this can be useful if you're not attacking.

Skills that are removed when you attack or use another skill can be useful, as the doppelganger will likely remove the skill immediately after using it, denying it the benefit of the skill that you get.

Self-healing skills can be dangerous, as if you can heal yourself and the doppelganger can also heal itself, that can easily lead to a stalemate in which neither of you can kill the other.

The doppelganger will not use most PvE-only skills at all, as mob AI was written assuming that mobs would not have access to PvE-only skills.

In hard mode, the doppelganger is level 30, which greatly increases both weapon and spell damage for any damage affected by armor. Armor-ignoring damage does not scale up, so it can help to use quite a bit of it to neutralize the doppelganger's advantage here.

Profession specific advice
If you have any problems defeating your doppelganger, look for profession specific tips below. Any class can defeat the doppelganger using only skills linked to the primary profession, though in hard mode, this is much more difficult for some classes than others. If you have a well-developed secondary profession and are having trouble, you may wish to look at secondary profession tactics. Another alternative is using PvE-only skills.

If you wish to take a new secondary profession for the specific purpose of defeating the doppelganger, the cheapest approach is to switch your secondary profession to mesmer. Acquiring the secondary profession gives you Empathy by default, without having to buy it separately, and you can beat the doppelganger by using empathy and an otherwise empty skillbar, by casting empathy and then dodging back and forth (and not attacking) until it wears off, and then repeating. Adding increased armor or blocking skills from your primary profession will give you more leeway, as the doppelganger will not benefit from them.

Please do not add strategies or builds that rely on the combination of a particular primary profession together with a particular secondary. While there are myriad such approaches that will work, few players will happen to have your particular combination of a primary and secondary profession. Advising them to go buy skills for a particular secondary profession is very wasteful.

Do be warned that many of the strategies listed below will fail in hard mode, especially if not in the hard mode subsections. Such tips may still be useful to those who do not have access to hard mode yet, nor to all of the skills that it may take to do well in hard mode.

Elementalist

 * Bring lots of skills with very long cast times. The Doppelganger will usually waste its time casting these skills, giving you plenty of time to kill it. When using this strategy, consider using skills like Meteor Shower or Maelstrom.


 * Step out of AoE DoT spells like Meteor Shower or Maelstrom; the Doppelganger usually will not.


 * Do not equip skills that could disrupt your spell casting (like Gale or Earthquake).


 * Cast glyphs before stepping on the last stone. This will give you an advantage in battle, as you will waste less time casting.


 * Cast Kinetic Armor before entering and bring a cheap, spammable spell with which you can keep kinetic armor up. Bring one fairly limited interrupt (so you won't be interrupted very much), and use it when the Doppleganger when tries to cast kinetic armor, leaving you with an enormous armor advantage.


 * Take Iron Mist, it will generally use it on you, making you invincible as long as you don't bring any Air Magic spells.


 * Take only the skills Aura of Restoration and Flare, before stepping on the last stone cast Aura of Restoration, when insde the Mesa, keep casting Flare until the Doppelganger dies.


 * Take Mark of Rodgort but bring no fire damage skills, just a Fiery weapon with a relatively quick attack rate. The Doppelganger will waste time casting it on you with no effect as it cannot deal fire damage, while you bring it down more quickly with degen. Combine with Conjure Flame to increase damage while still doing the Doppelganger no good.

Hard Mode Notes


 * Hindering its damage dealing ability may be of great help, as you do not have as high armor as other professions have. Blinding Flash or Blinding Surge is a good option to stop it from dealing too much damage with attacking, though it will still do far more damage with spells than you.


 * Bring Mark of Rodgort, Conjure Flame, Kinetic Armor, Stone Daggers, and nothing else. Put all of your attribute points into fire and earth magic; energy storage doesn't matter.  Bring a fire wand or staff.  Cast Conjure Flame and then Kinetic Armor just before entering.  Cast Mark of Rodgort immediately when the battle starts, then use your staff or wand to attack.  Cast Stone Daggers often enough to keep Kinetic Armor up.  You'll do damage mainly with Conjure Flame and the burning from Mark of Rodgort, both of which ignore armor and neither of which the Doppelganger can use, and the very high armor from Kinetic Armor will prevent the Doppelganger's attacks from hurting you very badly.

Mesmer

 * Backfire is a very useful skill. Consider using it with other cheap, harmless spells. Just cast Backfire on it and let it cast itself to death. Be careful not to let Backfire trigger on you though. (Placing it at the end of the skillbar will usually make it cast last by the Doppleganger).


 * Anti-melee hexes like Empathy, Clumsiness and Spirit of Failure can greatly help in letting the Doppelganger kill itself. Consider combining this with Spirit Shackles and Mind Wrack. When using this technique, just do not attack it. For example, you can bring Empathy with no other skills, max Domination magic, and a low damage staff. Keep recasting Empathy but do not attack with the staff.


 * Having Illusion of Weakness on your bar and casting it before entering the Doppelganger's arena can provide you with great healing. Placing the skill on the right of the skill bar makes it less likely the Doppleganger will use it.


 * Shatter Enchantment is a good idea. Take some cheap enchantments and let the Doppelganger cast them on itself, only to shatter them.


 * Be careful with interrupts. The AI almost always has faster reflexes than you, so it is likely you will get interrupted.

Hard Mode Notes


 * Due to its AI, the Doppelganger will not use spells when at low health and hexed with Backfire.

Monk

 * The AI will not use Regeneration skills like Healing Breeze to counter health loss, but will use it only to counter degeneration. Use this to your advantage.


 * Monks have little options to deal damage, so try focusing on Smiting Prayers.


 * Bring Retribution and Holy Wrath to let the Doppelganger kill itself. As this will drain your energy completely, use Signets to heal yourself.


 * Using Restful Breeze as an alternative to Healing Breeze along with Retribution and 12 points in Healing and Smiting prayers will guarantee no healing for the Doppleganger. It will kill itself in under 2 minutes this way, just don't attack.


 * Get the Doppleganger to cast Life Attunement to dramatically reduce damage from its attacks.

Hard Mode Notes


 * In Hard Mode, the AI will force the Doppleganger to use Healing Breeze.


 * Use Retribution, Shield of Judgment, Scourge Enchantment, and Restful Breeze. Cast retribution before the battle and leave it up for the entire battle.  Use shield of judgment as often as the cooldown allows.  Use scourge enchantment often enough to keep it on doppelganger constantly, as this will ensure that even with the divine favor healing, doppelganger's casts give it roughly no net healing.  Keep restful breeze on yourself most of the time, and do not attack, as this will end restful breeze.  Retribution and shield of judgment do enough damage to kill doppelganger in well under 2 minutes.


 * Use Ray of Judgement and Restful Breeze, and leave the rest of your skillbar empty. Keep restful breeze active while dodging but not attacking most of the time, but stop to cast ray of judgement when it is available.  Get out of the way when the doppelganger casts ray of judgement; the doppelganger is not smart enough to do likewise when you cast it.

Necromancer

 * Bring spells that require a health sacrifice. Don't use these skills yourself, but rather let the Doppelganger use them. By including Awaken the Blood as the first skill in your skill bar, the Doppelganger will use them first, thereby increasing the health sacrifice. The elite skill Order of the Vampire is a very good choice for this role. With a 17% max health sacrifice and a 5 second cooldown, the Doppelganger is likely to kill itself in seconds. With Monk as your secondary profession, Scourge Sacrifice works wonders with this strategy.


 * Take skills that inflict conditions upon yourself, such as Signet of Agony and Chilblains. Don't use them yourself, let the Doppelganger use them, giving itself conditions such as poison and bleeding, while you only take a small amount of damage.


 * Anti-melee hexes like Spiteful Spirit, Insidious Parasite, and Reckless Haste make killing the Doppelganger a lot easier. Cast the hexes on it, and let it kill itself without too much damage to yourself. You may also want to take Enfeeble.


 * Don't bring life steal skills or hexes such as Life Siphon and Life Transfer. The Doppelganger will likely also cast them on you, so at best it will be an even trade and cancel out.

Try this build: OAVCI7xwb5phnDWodRC Cast Awaken The Blood, Spiteful Spirit and Empathy first. With the Awaken The Blood, the rest of the sacrifice skills will take 96% of the health out. Empathy and SS seal the deal as long as you don't cast anything.
 * Remember that there will be nothing dying in this battle, so not only will Soul Reaping be worthless, anything that requires a corpse (such as any well spells, any minions, Soul Feast, Consume Corpse, Necrotic Traversal, etc.) will do you no good.

Hard Mode Notes


 * Anti-melee hexes work wonders.

Ranger

 * Bring many slow-casting Nature Rituals like Favorable Winds and Quickening Zephyr. The Doppelganger will waste time casting the rituals while you attack.


 * Equip bow attacks and stay within melee range of the Doppelganger; it will switch to its axe and thus be unable to use the bow attacks.


 * Alternatively, get your pet to do all the damage. Skills like Enraged Lunge, Call of Protection and Symbiotic Bond work pretty well. To prevent taking too much damage, try to hide behind a wall and let your pet do the dirty work. Another way is to just bring the skill charm animal, a high level pet along with a few arrows should defeat Doppelganger easily.

Hard Mode Notes


 * Even in Hard Mode, the Doppelganger will try to use any spirits before attacking. Use this to your advantage.


 * Toxicity, Poisonous Bite and Predator's Pounce is a great combo if you have all three campaigns and a high-level pet. Let the Doppelganger cast Toxicity for you. Keep it poisoned and spam Predator's Pounce.

Warrior

 * Equip Frenzy, but don't use it. The Doppelganger will, putting itself at a significant disadvantage. Couple this with a few attack skills, preferably energy-based so you  use them right away, and it will go down very quickly.


 * The Doppelganger does not use a shield, so bringing skills that require a shield (such as Shield Stance and Shield Bash) gives a significant advantage.


 * Equip an attack combo from left to right in reverse order (such as Final Thrust, Gash, Sever Artery). The Doppelganger doesn't understand the order certain skills should be used in, and prioritizes them from left to right on the bar when they are charged.


 * Any skills that cause you to lose all adrenaline (such as Wild Blow) can be a great benefit. Ignore them yourself and let the Doppelganger waste its own adrenaline using them on you.

Hard Mode Notes


 * An easy method to kill the Doppelganger is to use block skills like Riposte, Deadly Riposte and Gladiator's Defense. Stand close to the Doppelganger so it can attack you with its axe, and block all its attacks.


 * The 'attack chain in reverse order' strategy will not work on Hard Mode.


 * The Doppelganger will not use Frenzy.

Ritualist

 * A build which relies on a lot of spirits can work quite well, if you can prevent the Doppelganger from putting down the spirits. A good choice would be Dissonance, or perhaps Warmonger's Weapon.


 * An easy victory can be achieved by using the skills Vengeful Weapon combined with either Weapon of Remedy or Vengeful Was Khanhei. Let the Doppelganger attack you have these skills on you, but do not attack back.


 * Take useless spirits like Recovery, and let the Doppelganger waste its time casting the spirits while you kill it with Channeling Magic spells.

Hard Mode Notes


 * Vengeful Weapon combined with Vengeful Was Khanhei is a reliable tactic.

Assassin

 * Assassins have plenty of options to defeat the Doppelganger. By equipping Vampiric Daggers with high Critical Strikes and Dagger Mastery, you can easily kill it simply by attacking and without even using skills.


 * Don't take any Dual Attacks, but include hexes that trigger on them to have the Doppelganger waste its time and energy casting them.


 * As a general rule, if you can start a dagger chain that you can use but the Doppelganger will not, it is quite easy to out damage it.


 * Bring Deadly Paradox and some attack skills. It will disable its attack skills with Deadly Paradox, while you take advantage of them.


 * Shadow Walk is a good choice, combined with several enchantments that keep you alive. If the Doppelganger uses Shadow Walk, it will not be able to cast the enchantments.

Hard mode notes


 * Bring Shadow Form and Expunge Enchantments and get Doppelganger to waste the latter on a useless enchantment. Use shadow form yourself when you get low on life, and when the Doppelganger gets low on life and uses shadow form, remove it. This gives you more time to kill the Doppelganger than it has to kill you.


 * Bring Black Lotus Strike, Golden Lotus Strike, Golden Fang Strike, Death Blossom, Shadow Walk, Shadow of Haste, Smoke Powder Defense, and Flashing Blades. Put attribute points into dagger mastery and critical strikes, and ignore shadow arts.  When the battle starts, use flashing blades, and then, in order, black lotus strike, golden fang strike, death blossom, golden lotus strike, golden fang strike, and death blossom again.  The doppelganger will often prefer one of the other stances rather than flashing blades, or end flashing blades by using one of the other stances soon after casting it.  This lets you block most of the doppelganger's attacks while it cannot block yours.  Note that both you and the doppelganger are permanently enchanted by a mission effect, so golden fang strike will cause a deep wound.

Paragon

 * Use a lot of Spear Attacks, and stay in melee range. The Doppelganger will use its axe, and will not be able to use these attack skills.


 * Equip chants that have an effect based on spell casting, such as Aria of Zeal or Aria of Restoration. The Doppelganger will waste time and energy using these for no benefit.

Hard Mode Notes


 * It can be kind of close, but the spear attacks in melee range strategy still works.

Dervish

 * With high scythe mastery and using Vow of Strength, you can easily defeat the Doppelganger by simply attacking it.


 * A few high damage attacks (such as Reaper's Sweep, Irresistible Sweep, Pious Assault, or Victorious Sweep) should be enough to quickly overpower the Doppelganger before it can do the same to you.

Hard Mode Notes


 * For Hard Mode, the tactics described above are usually not sufficient, as the Doppelganger simply outdamages you. A good way of defeating the Doppleganger is to use Ebon Dust Aura with an Earth weapon. The Doppelganger will not be able to take advantage of Ebon Dust Aura, but you can. Try to keep it blind as much as possible, and kill it with your scythe.