Kidney Stone

5.100.440

Treasure Room Treasure Room

(page 4, column 15, row 4)(page 4, column 15, row 4)

Complete The Guardian (challenge #30) Complete Onan's Streak (challenge #29)

Kidney Stone is an unlockable passive item added in Afterbirth.

Effects

• -0.2 speed and maximum speed
• -17 range
• +2.0 tear height.
  • The increased tear height and decreased range results in overall slightly less firing distance.
• Occasionally, firing tears will cause Isaac to charge an attack with his head pulsating with a red color. After the attack has charged up, the fire button can be released to fire a kidney stone that deals extra damage while piercing enemies and walls, and to fire a barrage of tears afterward.
  • This effect occurs approximately every 25 seconds.
  • Isaac won't be able to fire tears normally until the kidney stone has been fired.
  • The kidney stone has approximately twice the range of normal tears.
  • The tears fired afterward are a bit inaccurate and can be fired slightly to either side.
  • The barrage will continue for its full length between Rooms, as will the state of charging the attack instead of firing tears.
• When Isaac has half a heart left, the urine that appears underneath Isaac upon entering rooms will be changed to red.

Strategy

• Activating this item before entering a difficult room, like a boss room, can allow you to deal a lot of damage right away. To do this, simply hold the attack button until you stop shooting tears.

Notes

• Tints tears red. This is only a cosmetic change.
• Incubus will still fire tears normally while retaining the barrage effect, making this a good item for Lilith.
  • The barrage from the Incubus will be in a straight line instead of an inaccurate burst.
  • The kidney stone itself will come out of Lilith, not the Incubus follower, even though she cannot fire tears. The barrage of tears will still only come from the Incubus.

Interactions

• Anti-Gravity: The stone will not hover and will travel regardless, otherwise behaves as expected.
• Brimstone: No effect. Speed down still applies. Range down applies to Azazel's Brimstone, making it difficult to use at base range.
• Dr. Fetus: Not recommended. Bombs have a very low range, making self-damage very likely.
• Epic Fetus: Overrides Kidney Stone.
• The Forgotten: When in skeletal form, the Forgotten will fire the stone and swing his club rapidly instead of shooting.
• Haemolacria: Overridden by Haemolacria. Only stat changes apply.
• Jacob's Ladder: The tear barrage will spawn sparks as normal; however, the stone will only spawn sparks when hitting enemies.
• Libra: The harsh speed and range down make Libra potentially a large stats down. Stats are increased during the barrage.
• The Ludovico Technique: Overrides Kidney Stone. Tear becomes red (cosmetic change).
• A Lump of Coal: The stone will not change the appearance or grow bigger as it travels but it will increase in damage as it travels.
• Marked: Occasionally, Isaac will stop automatically firing, and an attack key must be held to release the kidney stone and continue firing.
• Mom's Knife: Overrides Kidney Stone.
• Monstro's Lung: Overrides Kidney Stone.
• Number One: Number One's range down overrides Kidney Stone, for an additional -0.62. The stone is not affected by the range.
• Soy Milk: Stone will be reduced to starting tear damage and is significantly smaller.
• Technology: Overrides Kidney Stone.
• Tech X: Overrides Kidney Stone.
• Tiny Planet: The stone and barrage of tears that follow orbit the character.

Synergies

• 20/20/ The Inner Eye/ Mutant Spider: Fires more tears in tear barrage. Only fires one stone.
• Angelic Prism: The stone and tear barrage will quadruple if they pass through the prism.
• Compound Fracture/ Cricket's Body/ The Parasite: The stone cannot split into smaller stones.
• Lachryphagy: Fires a barrage of tears that tend to clump together into larger tears, along with a kidney stone which can also be fed and bursts.
• Pop!: Fires a barrage of eyeball tears, and the stone behaves like an eyeball tear.
• Technology Zero: Fires a barrage of tears connected via electricity. The stone will also be connected via electricity.
• Trisagion: Behaves exactly as expected except everything looks like beams.

Trivia

• This item is a reference to the kidney stone Matt Kap had removed in 2015, hence "Matt's kidney stone"
  • Matt Kap was a pixel artist on The Binding of Isaac: Rebirth and its expansions.

Seeds

 PC  ZX84 DLBX (First floor treasure room) (Both modes)