Null

null is a secret world that the player can encounter when they use Wrath (Sin) item to instakill the boss in the final room of Droids HQ. This world will immediately load instead of the spinning rune and the button appearing in the boss arena. Each room in Null is preset and will never be randomized. It is impossible to get a Vault in this world.

null cannot be reached on Ascension 15 or multiplayer sessions, due to the boss not getting instakilled and requiring you to defeat it legitimately. Activating Wrath (Sin) on the boss will instead incur its usual effects, while the boss has full immunity to its effects.

Environment
null has a blackish purple color scheme, with granite walls and floor. This world will always take place at night.

Upon entering null, all of your items are removed, your abilities are disabled, and you are given a Singularity Sword. The first room is simply a spinning rune of the floor with a button on the center. The second room contains a single Friendly Droid that you are forced to kill to proceed. All proceeding rooms will be empty except the last room, where there is a spinning Rune with a Wrath Sword on the center. Picking up this sword will end your run and give you a win and rewards.

null is completely dark, having pitch-black walls and a pitch-black floor. The time is set to night and there is no way to change it to day, due to you losing all your items and abilities but the Singularity Sword when accessing this world.

The first room in null has a button which you need to press to access the second room. The second room has a Friendly Droid that you are forced to kill in order to proceed. The third to ninth rooms are all empty, and each room has a slight delay before proceeding to the next empty room. The tenth room features a large spinning rune, with the Wrath (Sword) in the middle. Picking up the sword will end the game, and give the player a win, or a crown if they are playing a Crown Challenge.

Trivia

 * null is one of the four secret worlds in the game, the other worlds being The Darkness, Astray, and Respite.
 * Before Update 1.5, null was always accessed after Atomic Factory and comprised of a single spinning Rune with an elevated button that ends your run with a win when pressed.
 * null also used to only consist of one room.
 * It was possible to set the time to Day using a Lantern or Illumina as it did not clear your items at the time.