Nullifying Altar
The Nullifying Altar is a special structure found deep within the Sandcave, below the Overgrown Cavern. Its brickwork construction has 3 material basins, each engraved with an alchemical symbol indicating which material should be placed in the receptacle.
Once the correct materials (see Usage below) have been placed into each receptacle, all of your perks will be removed in a bright flash, and placed in the air overhead. Now with them above, you can choose to pickup or leave any perk you previously had, as they won’t disappear on pickup.
The altar exists in New Game Plus and Parallel Worlds; however, in NG+ it is located in the bottom-left of the Snow Chasm (see Maps for details).
Specific Interactions
- The Extra Life perk and Fungal Shifts are not removed.
- One-off perks such as Faster Wands are removed, but not placed in the air.
- Extra Health perks cannot be removed, but you will keep the health.
- Vampirism is removed and picking it up will apply the health reduction a second time.
- If you have high satiation and Iron Stomach, your satiation will be set to 100% when the perk is removed.
- Curse of Greed is not removed.
Usage
The alchemical symbols shown on the altar, from left to right, are those for: Blood, Whiskey, and Silver.
Spells that produce materials:
- Blood: Summon Deercoy, Blood, Blood Cloud, Touch of Blood
- Whiskey: Explosion of Spirits, Touch of Spirits, Sea of Alcohol
- Silver: Chaotic Transmutation (5.44% chance)
Removing Perks allows for collecting additional copies of non-stackable and limited stacking perks by saving perks in the world, such as Hungry Ghost and Extra Perk. However, this doesn't necessarily mean the perk effect will always stack in a useful way. For example, excess stacks of Glass Cannon or Teleportitis Dodge have no effect.
Perk Duplication
If the player has 
Polymorph when the nullifying altar is activated, the player will retain their perks, allowing for all perks (except one-offs) to be duplicated. However, polymorphing near the altar will cause a Stevari with 
Berserk to spawn, with a 50% chance of spawning near (and perhaps directly on) the player and a 50% chance to spawn above the altar.[1] After the player has polymorphed 3 times, Skoude will spawn instead.
Despite this danger, several methods can be used to safely duplicate perks:
- The polymorph detection range for which Stevari/Skoude will spawn is a circular area, centered above the altar, which extends from a bit into the Dense Rock below the altar to just into the Sandcave above it. Polymorphing outside this range can allow safe perk duping.
- An Egg with Destruction in the player's inventory will activate upon polymorphing, instantly killing both Stevari and Skoude. This can only be used when polymorphing into a sheep, otherwise destruction will likely target the polymorphed player as well.
- Peace with Gods will still allow Stevari/Skoude to spawn, but they will be friendly if the player has polymorphed into a sheep.
Trivia
- CAUTION: in some cases, restarting the game before reclaiming your perks has been known to result in the perks reverting to standard Holy Mountain perk behaviour, where picking up one perk will cause all others in the area to be removed.
- Materials which have been fungal shifted away will not work for the altar material checks: e.g. if Blood has been shifted to Water, then Water (transformed) will not work. However, materials which have been shifted to will work: e.g. if Water has been shifted to Blood, then Blood (transformed) will work.
- In the code, the altar consists of three entities (one for each basin) which check for their respective materials. The center basin is the only one which actually causes the perk removal to occur, and it simply checks that 3 (currently loaded) basins total have had their materials filled. Because of this, perk removal/duplication can be done with only whiskey (or whiskey and one of the other materials) by using a Long Distance Travel wand to load in 2-3 altars in quick succession.
- Although the message "You have angered the Gods" appears when polymorphing near the altar, this check is distinct from the Holy Mountain check and does not affect whether or not Stevari will spawn in Holy Mountains. Likewise, angering or enraging the gods in Holy Mountains has no impact on whether Stevari or Skoude will spawn above the altar.
- Perks at the altar can be rerolled by bringing a reroll machine from the Holy Mountain (using Circle of Buoyancy is one easy way to do this). Take care though: Rerolled perks will disappear when one perk is taken unless saved by Perk Lottery.
Gallery
Videos
Two older videos from before the Duping was made more difficult:
Notes
- ↑ Specifically, there is a 50% chance for Stevari/Skoude to spawn in the center of the Nullifying Altar chunk and a 50% chance to spawn 30 pixels above the player, with an additional +-40 pixel randomness in both x and y directions which is applied after the 50/50.