AlchemistNPC Wiki

Bill Cipher is a post-Moon Lord secret boss fought anywhere and any time of day. He can be challenging, so the player should be very well equipped before taking him on.


Bill Cipher doesn't spawn on his own and requires the player to summon him with the Dimensional Rift on the surface anytime. The Dimensional Rift is reusable, so Bill Cipher may be summoned any number of times.


Upon spawning, he will appear above the player, the background will change similarly to the Solar Pillar.


Bill will often fire projectiles towards the player, but will stop firing for a few seconds for when he is summoned or at specific amounts of health.

  • He will follow the player slowly throughout the entire fight.
  • He will shoot lasers towards the player, and will occasionally fire DeadlyLaser.png Deadly Lasers.
  • If he is below 15% health, he will start to fire Vaporizer.png Vaporisers.


Has two main phases :

Phase 1

Subphase 1
  • Shoots lasers towards the player, and will occasionally fire Deadly Lasers too.
  • Upon reaching 75% health, he will transition into his 2nd subphase.
Subphase 2
  • Lasers are fired out more often.
  • Upom reaching 50% health, he will then transition into his 2nd phase.

Phase 2

Rage Phase 1
  • Player receives the "Madness Unleashed" debuff inverting their controls.
  • Places some MadnessOrb.png Madness Orbs in the air which deal damage.
  • He will start to put debuff items in your inventory.
  • Lasers are fired way more often.
  • Shoots two Deadly Lasers at a time.
  • Fired lasers are more spread out.
  • Upon reaching 25% health, he will immediately transition into his 2nd rage phase.
Rage Phase 2
  • Upon damaged to 15% health, Bill will start to be outraged.
Death Mode
  • All lasers change into vaporizers which petrify the player.
    • They are fired at super high velocity.



  • "You dared summon me? This is going to be fun!"


  • "Hey you! Yes, you! I am asking the one who is controlling this "puppet"!"
    • "Do you really think that you would be able to defeat me? That's hilarious!" (When Bill Cipher drops below 75% health)
  • "Enough playing around, now you are gonna die!"
    • "Madness is unleashed!" (When Bill Cipher drops below 50% health)
  • "Don't think you can run from me, mortal!" (When the player goes far away from Bill Cipher)
  • "Hey catch this!" (When Bill Cipher puts a debuff item in your inventory)
  • "You are starting to annoy me, worm!"
    • "Don't start thinking you're safe behind that screen..."
    • "I will come to your dreams and will turn them into the horrible nightmare!" (When Bill Cipher drops below 25% health)
  • "I will not get defeated again!"
    • "Prepare to suffer!" (When Bill Cipher drops below 15% health)


  • If you are using any kind of god mode, you will instantly die if you touch him because of a debuff called Mind Burn.
  • Because of the fact that the Dimensional Rift is reusable, it is possible to summon more than one at the same time since that it can still be used even when the fight is still going on.
  • If your player's name is "Bill", Bill Cipher won't fight you because you're his namesake. At the same time, he will give you a gift - his treasure bag, even if your world is in Normal Mode


  • A hard counter to the debuff items is by having a completely full inventory. Or alternatively you can just autopause and remove the items manually.
  • The Ankh Shield is a must have, as knockback could knock you into him and that means you don't have to worry about getting the screaming head.
  • You can counter the flipping with Gravitation Potions or the Gravity Globe, although that means that in addition to flipped controls, you have to deal with left flipping the screen, so choose your poison.
  • A method of dealing with the contact damage inflicting Mind Burn is to utilize the effect of dodging, whether it's to be from the effect of some kind of ninja belt being based on chance, or by the effect of a guaranteed, but timed dodge, such as Shadow Dodge. This can be attained utilizing Blurring Potions, or by anything that allows to have a chance to negate taking damage. (Fargo's Soul Mod may be helpful, if you think it's worth to install.)
  • Circling around Bill on a platform arena works extremely well.
  • When you receive the "Madness Unleashed" debuff, autopausing and inverting your movement keys allows you to completely negate the debuff for the rest of the fight.
  • Equipping the Pocket Mirror stops Bill from being able to petrify you during his last phase.
  • Using the summon Counter Matter can act as a safeguard from bill's attacks. Stopping attacks from hitting you occasionally.


  • BillCipherBag.png Treasure Bag (100%)


  • Bill Cipher is from the popular cartoon tv series called Gravity Falls.
  • He is based on the Eye of Providence, which is most commonly seen on the back of the American dollar bill.