Binding of Isaac: Rebirth Wiki

(in Repentance)

Sharp Key is an activated item added in The Binding of Isaac: Repentance.

Effects[ | ]

  • Gives five KeyKeys.
  • On use, Isaac holds a key above his head. Pressing a fire button removes one key and throws it as a piercing projectile. The key damages enemies, as well as opens locked doors and Locked ChestLocked Chests it hits.
    • The key will also break the first rock it hits, as well as Key Blocks.
    • The thrown key does damage equal to 5x Isaac's damage + 30.
    • Enemies killed by Sharp Key have a chance to spawn the contents of a chest; the contents they can drop includes the rewards of any possible chest contents, including items.

Notes[ | ]

  • Sharp Key gives Isaac five keys for the price of three when bought at a ShopShop, making its purchase a good value if the player is low on keys.
  • Thrown keys follow the same unlocking rules as Collectible Dad's Key iconDad's Key: They can unlock Secret RoomSecret Rooms, the doors to access MinesMines, MausoleumMausoleum, Boss Mom's Heart ingameMom's Heart in Mausoleum/Gehenna, Mega Satan Head ingameMega Satan, and A Strange Door A Strange Door. However, it cannot be used as a substitute for Collectible Red Key iconRed Key or open the doors to Boss RushBoss Rush or ??????.
    • Doors will be opened in one thrown key, even if they require multiple keys or bombs to open.
    • The only rooms Dad's Key can open that Sharp Key cannot are Challenge RoomChallenge Rooms, Boss Challenge RoomBoss Challenge Rooms, the Boss RushBoss Rush door from Mom's boss room and the ?????? door from the inside.
      • The door of Boss RushBoss Rush can be opened from the inside by throwing a key to the center of the door.
  • Thrown keys can also destroy Angel statues, but not Blue Fire PlaceBlue Fire Places.
  • Thrown keys cannot pierce or destroy StoneyStoneys.
  • Destroying a rock will create a bridge at the opposite side the thrown key hit the rock from.
  • Despite being a substitute to bombs, thrown keys will not destroy ShopkeeperShopkeepers.
  • Thrown keys will open all the locked chests they move through, allowing multiple chests to be opened with a single key.
    • Only locked chests (such as Locked ChestLocked Chests, Eternal ChestEternal Chests, or Old ChestOld Chests) can be opened by Sharp Key; all other chests are unaffected.
      • In the case of Eternal Chests, thrown keys will only count toward opening the chest one time.
      • Despite Mega ChestMega Chests requiring keys to unlock, Sharp Key has no effect on it.
    • Opening locked chests with thrown keys in Challenge rooms will not cause the challenge room to start spawning enemies.
  • Thrown keys will retain Isaac's tear/status effects, but are unaffected by items that replace Isaac's tears (such as Collectible Dr. Fetus iconDr. Fetus, Collectible Brimstone iconBrimstone, or Collectible Mom's Knife iconMom's Knife).
  • Whether or not an enemy gives chest contents when killed by Sharp Key is seeded per enemy. As such, rooms can be re-entered (using Sharp Key itself or with Door StopDoor Stop / Collectible Mercurius iconMercurius etc.) before they're fully cleared to repeatedly get rewards from the same enemy.
  • The type of chest that enemies will give the contents of is determined by standard chest generation rules. This makes the contents of standard chests more common, and prevents enemies from giving the contents of Old ChestOld Chests or Mom's ChestMom's Chest.
  • The pickups enemies killed by Sharp Key can drop are affected by items/trinkets that modify chest spawns/rewards.
  • Sharp Key can open the chests in Challenge RoomChallenge Rooms without triggering them. However, picking up an item dropped from a chest will trigger them.

Synergies[ | ]

  • Ace of SpadesAce of Spades / Child's HeartChild's Heart / Lucky ToeLucky Toe / Match StickMatch Stick / Rusted KeyRusted Key / Safety CapSafety Cap: If an enemy drops pickups, it has a ⅓ chance to drop an extra pickup; the pickup will be the one the trinket is associated with (random in the case of Lucky Toe).
  • Collectible Angelic Prism iconAngelic Prism: A thrown key will duplicate into 4 keys, which can be used to open multiple rooms or chests with only 1 key. If Isaac stands at the middle far left or middle far right of the first room in ChestChest, a thrown key can open all 4 chests.
  • Collectible The Book of Belial iconThe Book of Belial + Collectible Birthright iconBirthright as Character Judas iconJudas / Character Dark Judas iconDark Judas: Invokes the effect of Collectible Razor Blade iconRazor Blade without dealing damage to Judas along with the original effect.
  • Collectible Book of Virtues iconBook of Virtues: Spawns white wisps in the shape of keys, on the middle ring. Despite the wisps' appearance, they cannot unlock anything, and act as normal wisps.
  • Collectible Continuum iconContinuum: Thrown keys can unlock multiple doors it passes through.
  • Gilded KeyGilded Key: Enemies will only give the contents of locked chests. The pickups they can drop will also include runes and Lil' BatteryBatteries.
  • The Left HandThe Left Hand: Enemies will only give the contents of red chests.
    • As locked/red chests are able to give Items whereas normal chests cannot, the previous two trinkets also allow items to be obtained through Sharp Key more consistently.
  • Collectible Mom's Key iconMom's Key: Doubles the amount of pickups dropped by enemies.

Interactions[ | ]

  • Collectible Car Battery iconCar Battery: No effect.
  • Daemon's TailDaemon's Tail: Enemies are much less likely to drop hearts; these hearts will still be Black HeartBlack Hearts.
  • Collectible Dead Eye iconDead Eye: Keys thrown will contribute to Dead Eye's damage modifier.
  • Golden Keys: Ignored by Sharp Key; it will still require and consume keys to use.
  • Collectible Guppy's Eye iconGuppy's Eye: There will be no overlay on enemies that would drop pickups on death.
  • Collectible Haemolacria iconHaemolacria/Collectible The Parasite iconThe Parasite: Split tears from thrown keys are normal tears.
  • Collectible Kidney Stone iconKidney Stone / Collectible Number One iconNumber One / Collectible Pluto iconPluto / Collectible Inner Child iconInner Child's revive: Sharp Key loses almost all of its range, and can only be improved with tear height ups.
  • Collectible The Ludovico Technique iconThe Ludovico Technique: No effect.
  • Collectible Multidimensional Baby iconMultidimensional Baby: Keys passing through the baby turn into normal tears and loses all of its effects.
  • Collectible Pay To Play iconPay To Play: The key cannot unlock doors that originally were accessible by keys, but can still open chests and open secret room doors.
  • Poker ChipPoker Chip: Enemies have a 50/50 chance to spawn extra pickups or an Attack FlyAttack Fly: The attack fly will be instantly killed by the thrown key.
  • Spectral Tears: Rocks that thrown keys pass over have a chance of being destroyed.
  • Collectible Trisagion iconTrisagion: Thrown keys become Trisagion blasts and no longer cause enemies to drop chest contents on kill.

In-game Footage[ | ]

Trivia[ | ]

  • Sharp Key originates from the Antibirth mod where it was less powerful as killing enemies with it did not drop chest contents.
  • This item can be considered to be the Key counterpart to Collectible Blood Bombs iconBlood Bombs. Both items can use their respective pickups at the expense of another, with Sharp Key sacrificing Keys, while Blood Bombs sacrifices health.