Void 
Effects
- Upon use, destroys all pedestal items in the room. Items that require payment can not be absorbed unless they are bought first.
- If Void destroys an active item, it gains the activated ability of that item - whenever Void is used, it will simultaneously use all previous active items that were absorbed in the same order they were absorbed. Passive effects of absorbed active items will not apply (i.e. the passive effect of
Mom's Box).
- If Void destroys a passive item, Isaac gains 2 random stat boosts. Possible stat changes include:
- +1 flat Damage
- +0.5 Tears (Added in Repentance) which also boosts the regular tear limit
- +0.2 Speed
- (Removed in Repentance) Also affects maximum speed (may never exceed 2.0)
- +0.2 Shot Speed
- +1 Luck
- +0.5 Range
- If speed or tears are at their maximum and are chosen, there will be no visible increase.
- (Added in Repentance) This still applies to the tears stat, however it is more difficult to see as the hard tear cap has been increased to 120.
Notes
- (Apollyon) Apollyon starts with this item by default.
- Using Void to absorb items in (Boss Rush) Boss Rush or (Challenge Room) Challenge Rooms counts as taking the items and will cause waves of bosses or enemies to start spawning.
- (Removed in Repentance) The ability of the newly absorbed active item(s) will activate even if the item has no charge. Using any multiple-use item before absorbing it with Void will effectively allow Isaac to use the item twice.
- (Added in Repentance) If Void is used while Isaac is holding an item above his head, it can still consume the item, allowing to immediately absorb passive items bought from (Devil Room) Devil Rooms, (Black Market) Black Markets, or (Shop) Shops. This also can be used to give Isaac a chance to see what an unknown item is before deciding if he wants to consume it, in the case of an active Curse of the Blind or a (Treasure Room) Treasure Room in (Downpour) Downpour, etc.
- This does not apply if Void had previously absorbed an active item that normally hold itself above Isaac's head, i.e.
Bob's Rotten Head.
- (Added in Repentance) The newly absorbed active item(s) won't be used right away, but with the next usage of Void.
- (Added in Repentance) If Isaac absorbs items from a room with choice pedestals, it will only absorb one item, and the other item vanishes as if Isaac took it.
- If Isaac finds another Void, such as during a Victory Lap where it is left behind in the previous lap, it will have the same active effects stored in it as the other Void.
- Consuming a second Void will create no effect.
- If multiple copies of an active item are absorbed, using Void will activate that effect equally many times.
- Stat boosts upon destroying passive items are determined by the seed and are tied to the number of items destroyed, not the items themselves. If Isaac runs the same seed and chooses to consume different passive items, the same stat boosts will be gained.
- Stat boosts are permanent and are retained if Void is dropped.
- Using Void to absorb
Key Piece 1 and 
Key Piece 2 will not permanently remove them from the run. They will continue to spawn after defeating Uriel or Gabriel no matter how many times Isaac uses Void on them, as long as he does not pick them up normally.
Synergies
- (Added in Repentance)
Book of Virtues: Spawns the wisps of all the active items Void has absorbed. Spawns no wisps by itself. Using Void on Book of Virtues will give stat upgrades instead of its normal effect, as Book of Virtues is considered a passive item.
Breath of Life: Immediately grants invincibility frames.
- (Removed in Repentance)
Crooked Penny: Using Void with the Crooked Penny absorbed will result in items in the room being absorbed as usual, but afterwards new copies of the items or one coin are spawned.
- (Added in Repentance) If Crooked Penny deletes the contents of the room, they will not be consumed by Void.
- (Added in Repentance)
Eraser: Allows the Eraser to be used multiple times per floor.
- (Removed in Repentance)
More Options / (Removed in Repentance)
There's Options: Using Void will cause both items to be absorbed.
Interactions
- (Added in Repentance)
Abyss: If Void consumes Abyss, the latter will take priority and using Void to consume another item pedestal will generate a locust. Even consuming active items will generate a locust, and Void will not copy that active item's effect. This essentially causes Void to act identically to Abyss, albeit requiring 2 more charges per use.
Blank Card + (? Card) ? Card: Using the ? Card with an absorbed Blank Card simply activates Void. Isaac will not be teleported to the (I AM ERROR) I AM ERROR room and Void will not be deleted.- (Broken Remote) Broken Remote /
Teleport! / 
Teleport 2.0 / 
Undefined / any other teleport method: Void will still consume any item pedestals in the room, after which the teleport occurs.
- (Added in Repentance)
Clear Rune + (Soul of Lilith) Soul of Lilith: The familiar that the latter generates will immediately be consumed by Void.
Clicker: If Void is either Isaac's only item or the item most recently picked up, it will be lost upon absorbing and thus activating the Clicker.
The D6 / 
D100: If absorbed while there are other pedestal items in the room, it will reroll the items before absorbing them. Likewise, if The D6 or D100 was previously absorbed and Void is used, pedestal items will get rerolled before being absorbed.- (Removed in Repentance)
D Infinity: When absorbed and Void is used, replicates the effect of a random die item.
- (Added in Repentance) Acts as a copy of one of the 10 dice D Infinity can replicate. This die is randomly chosen and does not change.
- (Removed in Repentance)
Diplopia / 
Forget Me Now / 
Pandora's Box / 
Mama Mega! / 
Mystery Gift / any single-use active item: They are used once upon being absorbed, but their effects are not absorbed and will not activate with subsequent Void uses.
- (Added in Repentance) Single-use items won't be used upon their absorption, instead being invoked on the next usage of the Void, which allows Isaac to use the absorbed item later when needed. Their effects will still only be invoked once.
- (Added in Repentance) Diplopia: On the next use, the pedestal items in the room will be consumed but another copy of the items will be spawned afterward.
- Diplopia + Mystery Gift: If both items are absorbed in the same room, the next use of Void will only trigger Diplopia, with the use afterward activating Mystery Gift
- (Added in Repentance)
Everything Jar: Consuming Everything Jar will cause Void to spawn a poop when used, regardless of charge level.
- (Removed in Repentance)
Glowing Hour Glass: Upon using Void, Isaac is sent to the previous room and most changes are reverted, nullifying many other effects that Void may have absorbed. If the Glass is absorbed in a shop, Isaac is sent back to the previous room, but the Glass will be unused in the shop on its pedestal. This allows for an infinite shop donation circle, eliminating the need for a battery to be present in the shop.
- (Added in Repentance) Charges are reset back to full upon each use, allowing for infinite re-tries of any room. This does, however, prevent any other items consumed previously from being invoked, and usually prevents Isaac from absorbing new items.
The Jar: Absorbing it with Void will not allow Isaac to pick up excess hearts.
Jar of Flies: Absorbing it with the Void will not allow the collection and generation of flies.- (Added in Repentance)
Jar of Wisps: Each use will spawn only one wisp.
Moving Box: Moving Box will not be added to Void; instead, it is converted into stat boosts like a passive item.
Remote Detonator: Absorbing it with Void does not cause bombs to remain on the ground until Void is used, but using Void explodes all player-placed bombs as usual.- (Added in Repentance)
Spin to Win: A spinning top orbital will spawn every time the Void is used. The orbitals will last until Isaac leaves the room.
- (Added in Repentance)
Stitches: Absorbing it with the Void won't do anything since the familiar doesn't spawn.