In order to start collecting essence, you need to acquire the Dream Nail which can be found in the Resting Grounds. There are several first-time access points to the Resting Grounds which require different amounts of progress:

• Falling into Resting Grounds from Crystal Peak: Crystal Peak entry (from the right side of the Crossroads) requires either 1) the Lumafly Lantern (1800 Geo) + 50 Geo gate fee or 2) the Desolate Dive spell (Soul Master boss fight in City of Tears).
  
  > The Lumafly Lantern is recommended because getting to the pit leading down to Resting Grounds requires traversing one or two dark rooms which need the lantern so you can see where you're going. The fall down to the Resting Grounds is in the bottom right of Crystal Peak.
  
  
• Blue Lake entrance above Salubra's shop in Forgotten Crossroads: Requires Super Dash (i.e. finding the Crystal Heart in Crystal Peak).
  
  > Use Mantis Claw to climb up the outside of the right wall of the room where you fought the Gruz Mother and super dash across the room from near the ceiling. Alternatively, if you are playing in Normal Mode you can die and use your shade to nail bounce up to the secret passage.
  
  
• Forgotten Crossroads <-> Resting Grounds tram: Accessing the tram requires finding the Tram Pass in the Failed Tramway (middle and top part of Deepnest).
  
  > Once you have the Tram Pass, the tram is located on the right side of the Crossroads just above the Gruz Mother boss room.
  
  
• City of Tears <-> Resting Grounds elevator: The elevator is located in the right half of the City of Tears, so access to it requires entering the Royal Waterways with a Simple Key and beating Dung Defender. (Note: You could also use the Deepnest <-> Ancient Basin tram after finding the Tram Pass and climb up to the City, but if you have the Tram Pass you can just take the Crossroads <-> Resting Grounds tram as mentioned above.)
  
  > Climb up the broken elevator shaft to enter the City of Tears and head right until you enter King's Station. Go into the passage at top of the station and look for a passage leading to the left in the top half of the new room.

Once you reach the Resting Grounds for the first time, simply find the platform with the statues of the three Dreamers and walk onto it:



















Once on it, you will be locked in by a white bubble. Interacting with the plaque on the platform gives an explanation of the Dreamers, after which you will get some dialogue from the Dreamers themselves. After blacking out, you will wake up in the Dream realm with no visible way out. After waiting about 8 seconds, a moth spirit will spawn and fly away, revealing some platforms. Follow the spirit via the platforms and after a little bit the moth spirit will stop at a platform with a moth statue. Interacting with the spirit here will give some dialogue and cause an item to spawn after it disappears. Collecting the item gives the Dream Nail.

Dream Nail pick-up in Dream realm:



















There are four different ways of acquiring essence in the game, which will be elaborated on in their separate sections later in the guide:

• Whispering Roots will release red orbs into their respective rooms with each orb giving one essence up to a total of 18-51 essence per root when all the red orbs are collected.
  
• Warrior's Graves are mini-boss fights which upon completion reward 100-250 essence.
  
• Dream Bosses are harder variants of previously beaten bosses which upon completion reward 300-400 essence.
  
• Spirits immediately give one essence each upon striking them with the Dream Nail.
  
• Normal enemies will drop one essence as a rare drop on death (chance is on the order of a few percent).

• Besides being used for collecting essence, when used against "living" enemies the Dream Nail reveals dialogue as well as fills your Soul meter.
  
• The Dream Wielder charm significantly decreases the charge time to strike with the Dream Nail as well as drastically improves the amount of Soul you gain per strike.

After the Seer retrieves you from the Dream realm when you acquire the Dream Nail, she will hand out rewards when you speak to her after reaching certain essence amounts. The required essence amounts and associated rewards are as follows:

• 100 = Hallownest seal
  
• 200 = Glade of Hope unlocked
  
• 300 = Pale Ore
  
• 500 = Dream Wielder charm
  
• 700 = Vessel Fragment
  
• 900 = Dream Gate ability
  
• 1200 = Arcane Egg
  
• 1500 = Mask Shard
  
• 1800 = Awoken Dream Nail (Achievement: Awakening)
  
• 2400 = Seer's final words (Achievement: Ascension)

In addition to the two achievements for collecting the 1800 and 2400 essence rewards, there is also an achievement (Attunement) for collecting 600 essence with no reward from the Seer. Note that this achievement does not require a visit to the Seer to unlock.

Notes:

• The Awoken Dream Nail is required for the "Dream No More" and "Sealed Siblings" endings of the game. To collect 1800 essence, you want to fight a minimum of one Dream Boss (using the essence totals below).
  
• Even though the Dream Bosses do not directly contribute to completion, they indirectly do so because the Seer's final words give +1% to completion, so a minimum of 2400 essence must be collected (requires at least 3 Dream Bosses w/o farming). You must also fight all seven Warrior's Graves because those fights do contribute to completion percentage.
  
• With the addition of essence drops from normal enemies, it is no longer necessary to rely on fixed essence sources to reach the above totals. Given that essence is a rare drop (a few percent per kill), however, it is still recommended to collect essence from the fixed sources. Fighting the Dream Bosses for essence is especially recommended if you don't want to waste time farming or are aiming for a speedrun achievement.

For those simply looking for essence counts (ordered from greatest to least within each category):

3208 essence from fixed sources (with 301 essence missable)

482 essence total

• Kingdom's Edge = 51
  
• Howling Cliffs = 46
  
• Deepnest = 45
  
• Greenpath = 44
  
• Ancestral Mound = 42
  
• Ancient Basin/City of Tears broken elevator = 35
  
• Glade of Hope = 34
  
• Queen's Gardens = 29
  
• Forgotten Crossroads = 29
  
• City Storerooms = 28
  
• Crystal Peak = 21
  
• Resting Grounds = 20
  
• Fungal Wastes/Fog Canyon connector (opposite Leg Eater vendor) = 20
  
• Hive = 20
  
• Fungal Wastes = 18

1100 essence total

• Markoth = 250
  
• No Eyes = 200
  
• Galien = 200
  
• Marmu = 150
  
• Elder Hu = 100
  
• Gorb = 100
  
• Xero = 100

1600 essence total

• Lost Kin = 400
  
• Soul Tyrant = 300
  
• Failed Champion = 300
  
• White Defender = 300
  
• Grey Prince Zote = 300 (missable)

26 essence total

• Glade of Hope: 19
  
• Rest of map: 7 (Note: 1 spirit will not spawn if certain encounters aren't found)

Whispering Roots are small trees that can be found over the realm of Hallownest. Once the Dream Nail is acquired, they will glow when you get near them. Striking a Whispering Root with the Dream Nail adds Dream effects and releases many red orbs into the room the Root is in (i.e. the breadth of the map you can reach without a screen transition), with each red orb giving one essence when collected. Once all the red orbs from a Root have been found, the Dream effects disappear and the Root will twist into a new shape along with giving a sound effect to indicate completion.

Note: The directions with which the red orbs fly away from the Root indicate the directions of the locations of the red orbs within the room. Furthermore, if you haven't collected all the Root's red orbs you can leave the room, come back, and then strike the Root again to cause the Root to respawn the uncollected orbs. The orbs will then fly off into the room once more. Using the respawn is particularly useful in tracking down the last few missing orbs from a Root.

There are 15 total known Whispering Roots in the game which give a total of 482 essence as of v1.2.2.1.

• Kingdom's Edge = 51 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Howling Cliffs = 46 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Deepnest = 45 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Greenpath = 44 essence
  (Note: Requires cutting down platforms from both the Greenpath and Queen's Gardens sides)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Ancestral Mound = 42 essence
  (Note: Requires Monarch Wings (i.e. Double Jump); next to Lifeblood Cocoon)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Ancient Basin/City of Tears broken elevator = 35 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Glade of Hope = 34 essence
  (Note: Must obtain 200 essence for Seer to open Glade of Hope)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Queen's Gardens = 29 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Forgotten Crossroads = 29 essence
  (Note: Breakable ceiling; requires Mantis Claw (i.e. Wall Jump))
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• City Storerooms = 28 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Crystal Peak = 21 essence
  (Note: Requires Monarch Wings (i.e. Double Jump))
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Resting Grounds = 20 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Fungal Wastes/Fog Canyon connector (opposite Leg Eater vendor) = 20 essence
  (Note: Requires Isma's Tear (i.e. acid immunity) or Shade Cloak (i.e. ability to pass through dark gates))
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Hive = 20 essence
  (Note: Requires Monarch Wings (i.e. Double Jump))
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Fungal Wastes = 18 essence
  (Note: Requires Mantis Claw (i.e. Wall Jump))
  

Initial Whispering Root:








Struck Whispering Root:











Whispering Root Complete:





















Red Orb:

Warrior's Graves are grave markers spread throughout Hallownest. Once you have the Dream Nail, a spirit will spawn on top of each marker when you get near it. If you interact with the spirit, you get some dialogue and then you can choose to challenge the spirit to a fight. You can also directly Dream Nail the spirit to start the fight immediately.

For tips on defeating the Warrior spirits, please refer to my Hallownest Bosses guide:
http://steamproxy.net/sharedfiles/filedetails/?id=889617082
There are 7 total known Warrior's Graves in the game which give a total of 1100 essence as of v1.2.2.1.
(Note: Warrior's Graves give 1% completion for beating the spirit in addition to the essence reward.)

• Markoth = 250 essence
  (Note: Requires Shade Cloak)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• No Eyes = 200 essence
  (Note: Requires Lumafly Lantern)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Galien = 200 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Marmu = 150 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Elder Hu = 100 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Gorb = 100 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Xero = 100 essence
  

Dream Bosses are harder variants of boss fights you previously beat in the game. Once you acquire the Dream Nail, Dream Bosses are indicated by the presence of Dream effects over their bodies. Upon using the Dream Nail on the boss corpse, you will be transported into the Dream realm after which you need to perform some platforming to reach the boss room. Once the boss is defeated, either A) a spirit will spawn above the boss corpse in the real world and interacting with the spirit will give dialogue, after which you will be rewarded with essence or B) you will immediately receive the essence after being ejected from the dream realm.

General Notes:

• You will always start these fights with full health, regardless of what amount of health you had when you entered the Dream realm. In contrast, your soul meter will be at whatever level you had in the real world when you entered the Dream realm.
  
• When you lose all your health to a Dream Boss, you are ejected from the Dream realm and wake up in the real world with full health. However, your Soul amount will be fully depleted regardless of how much soul you had remaining when you died in the fight.
  
• You cannot "die" in Dream Boss fights, so Fragile charms won't break and you won't have to worry about retrieving your Shade. You also respawn directly next to the boss corpse so no walk-back from the last bench is required.
  
• Upon successfully defeating a Dream Boss you will wake up in the real world with exactly the amount of remaining health and Soul as you had when you were ejected from the Dream realm for beating the boss.

For tips on defeating the Dream bosses, please refer to my Hallownest Bosses guide:
http://steamproxy.net/sharedfiles/filedetails/?id=889617082
There are 5 dream bosses in the game which give a total of 1600 essence (with 300 essence missable) as of v1.2.2.1.
(Note: The Nightmare King boss obeys the above rules but does not award essence for winning the battle, so it is excluded from the list. The Radiance boss only obeys the first rule and does not award essence for winning the battle, so it is also excluded from the list.)

• Lost Kin (Dream variant of Broken Vessel) = 400 essence
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Failed Champion (Dream variant of False Knight) = 300 essence
  (Note: Requires Mantis Claw (i.e. Wall Jump))
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Soul Tyrant (Dream variant of Soul Master) = 300 essence
  

• White Defender (Dream variant of Dung Defender) = 300 essence
  (Note: Requires Desolate Dive, defeating the 3 Dreamers)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Grey Prince Zote (Bretta's dream version of Zote) = 300 essence
  (Note: Requires saving Zote in Greenpath/Deepnest, fighting Zote in the Trial of Warriors at the Colosseum, and saving Bretta in Fungal Wastes, therefore missable)
  Location: In the basement of Bretta's hut
  

Spirits give dialogue when you interact with them and striking them with the Dream Nail gives one essence per spirit. The total number of spirits (and therefore essence from spirits) in the game is 26 as of v1.2.2.1.

There are 19 spirits total in the Glade of Hope (opened by the Seer as the 200 essence reward), which has its entrance located here:


















Note: With the Hidden Dreams update, Revek will start attacking you every time you Dream Nail a spirit in the Glade of Hope and won't stop until you leave the Glade. Attack is a quick swipe that does 2 damage per hit (dodge by Shade dash or well-timed parry). Revek can only be put to rest when you have Dream Nailed every other spirit in the Glade, at which point Revek acts like a normal spirit when they respawn at their grave after you leave and re-enter the Glade and can be Dream Nailed normally.

Spirits of the Glade of Hope:

• Revek
  
  
  
  
  
  
  
  
  
  
  
  
  
• Millybug
  
  
  
  
  
  
  
  
  
  
• Caspian
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Dr. Chagax
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Atra
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Garro
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Kcin
  
  
  
  
  
  
  
  
  
  
  
  
• Grohac
  
  
  
  
  
  
  
  
  
  
  
  
  
• Hundred Nail Warrior
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Karina
  
  
  
  
  
  
  
  
  
  
  
  
  
• Perpetos Noo
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Molten
  
  
  
  
  
  
  
  
  
  
  
  
• Magnus Strong
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Waldie
  
  
  
  
  
  
  
  
  
  
  
  
  
• Wayner
  
  
  
  
  
  
  
  
  
  
  
  
• Wyatt
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Hex
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Thistlewind
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Boss
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

Spread over the rest of the map, there are 7 spirits total (with one missable spirit if certain encounters are not met):

• Grave Digger (Right of the Well - Dirtmouth)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Joni (Joni's Repose - Howling Cliffs)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Marissa (Pleasure House - City of Tears)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Poggy Thorax (double secret room in one of the right alcoves (4th from bottom) of the elevator shaft leading up to the Pleasure House - City of Tears)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Hive Queen Vespa (Innermost part of Hive - Kingdom's Edge)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Caelif & Fera Orthop (Near first bench / Cornifer's location - Queen's Gardens)
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Cloth (Traitor Lord boss room - Queen's Gardens) - missable
  Requirements: First meet her in Fungal Wastes and talk to her after "rescuing" her in the Ancient Basin left tramway room by killing all enemies in the top left part of that room before the Traitor Lord boss fight.