Metronome

"Waggles a finger"
Entity ID	5.100.488
Recharge Time	2 rooms
Item Pool	Crane Game Wooden Chest Treasure Room Shop
Collection Grid	(page 5, column 3, row 1) (page 5, column 4, row 1)
Unlock Method	Defeat Ultra Greedier as Eden

Metronome is an unlockable activated item added in Afterbirth †.

Effect

• Grants a random item's effect for the current room.

Notes

• Beware using this as The Lost, as it can trigger self-harm items and kill him.
• Using this item multiple times in the same room will replace the previous item with a new one.
• Metronome cannot grant the effects of itself, Glowing Hour Glass, or Plan C.
• Keep in mind that you can trigger items you haven't unlocked yet, which means you could trigger the effect of items like Death Certificate without having to go through the trouble of unlocking them.
• If Metronome triggers the effect of Genesis, it will disappear from the active slot, just as with the real item.

Interactions

• Blanket / Holy Card / Holy Mantle / Wooden Cross: if Metronome is used while the shield is active, any stat changes or familiars/orbitals generated from Metronome will persist between rooms until Metronome is used again or replaced with another active item. Items that modify your stats and have other additional effects will keep the stats but the effect will be gone after leaving the room. For example, the tears down applied from The Inner Eye will persist between rooms, but Isaac will not shoot three tears at once.
  • Some tear effects from items will remain active between rooms. These include:
    • Continuum, Epic Fetus, Eve's Mascara, Godhead, Ipecac, Jacob's Ladder, The Ludovico Technique, A Lump of Coal, Monstro's Lung, My Reflection, Ouija Board, Pop!, Rubber Cement, Sacred Heart, Spoon Bender, Strange Attractor, Technology Zero
  • Some items behave unusually after leaving the room while the Holy Mantle shield was active:
    • Items that grant flight: Isaac's appearance is reset back to normal, but he is still able to fly.
    • 1up!: the mushroom familiar continues to follow Isaac, but doesn't grant an extra life.
    • Cupid's Arrow: the tear appearance is reset back to normal, but the tears still travel through enemies.
    • Fire Mind: the tear appearance is reset back to normal, but tears can still explode when they hit an enemy.
    • Mysterious Liquid: the tear appearance is reset back to normal, but tears will still leave green creep on the ground.
    • Spear of Destiny: does not persist between rooms.
• Car Battery: Metronome is activated twice at once as expected, but the item chosen for the first activation is shown raised above Isaac's head, instead of the second one that actually remains active.

Specific Item Effects

• Certain items used by Metronome have permanent, limited/unusual, or no effect. It is not clear what is intended and what is a bug.
• Permanent effects include:
  • Health, coins, bombs, or keys that are granted to Isaac directly will persist.
  • Clicker will permanently remove the latest item and change character.
  • Cube of Meat granted by Potato Peeler will persist.
  • D8's rerolled stat multipliers will persist, D4 or D100 will reroll all items permanently and D Infinity mimicking any of the previous also has the same effects.
  • Damocles will permanently grant the passive version of Damocles.
  • Dataminer's stat changes will persist.
  • Forget Me Now will restart the level.
  • Magic Skin will give Isaac a broken heart, spawn an item, and count as an activation of Magic Skin, causing future items to have a chance of being replaced by Magic Skin.
  • R Key will restart the run, retaining all items.
  • Void absorbing passives and granting stats will persist.
• Limited and unusual effects include:
  • Items do not spawn pickups and consumables that they might when picked up normally.
  • Items that adjust Isaac's size will not do so.
  • 1up! and Guppy's Collar give no indication of extra lives, but will still work if you die in the room.
  • Abaddon will not remove red hearts or grant black hearts.
  • Belly Button and Mom's Purse allow picking up two trinkets in the room, but if another one is picked up outside, one trinket disappears completely along with the extra slot.
  • Black Candle only adds a black heart and does not remove curses.
  • Brittle Bones and Divorce Papers do not grant bone hearts. Brittle Bones can still be used to gain permanent tears ups if bone hearts are available.
  • Crown of Light only adds soul hearts, no damage multiplier.
  • Dead Cat will only restore one red heart without setting heart containers to 1. It also gives no extra lives.
  • Deep Pockets, Little Baggy, Polydactyly, and Starter Deck allow picking up two consumables while in the room and kept outside, but using them will lose the extra slot.
  • Eden's Blessing will not grant an extra item for the next run.
  • Fate only grants flight, no eternal heart.
  • PHD will not identify pills, but they are still guaranteed to not be negative.
  • Schoolbag allows picking up two activated items while in the room and they can be kept even outside, but the extra slot and one of the items is lost if another activated item is picked up.
• The following items remain active until the Metronome is used again or replaced with another active item:
  • Mom's Knife
  • Technology
• The following items have no effect:
  • Items that only spawn pickups or consumables are not mentioned separately.
  • Ankh, Blue Map, Breath of Life, Broken Watch, Camo Undies, C Section, The Candle, The Compass, Contagion, Death's List, Experimental Treatment, Holy Mantle, The Jar, Judas' Shadow, Lazarus' Rags, Marrow, The Mind, Missing No., More Options, Poke Go, Purity, Red Candle, Spelunker Hat, Treasure Map

Trivia

• The name, pickup quote, and effect of this item are a reference to the move 'Metronome' from the Pokémon franchise.
• This item works similarly to the item Dead Sea Scrolls.

Bugs

Bug!	PC It is possible for this item to use an item that can teleport one to the I AM ERROR room. During the Mother Boss fight, this can happen. Using the trapdoor causes the game to crash.

Bug!	PC It is possible for this item to give an indefinite Breath of Life effect that persists throughout rooms, eventually killing the player.

Bug!	PC If Urn of Souls is activated through Metronome, it won't shoot fire and Isaac could get stuck with the urn in his hands unable to shoot tears. You can fix this by exiting and continuing the run, restarting the room without the urn and without Metronome charges.

Bug!	PC Using Metronome in the Cantripped! challenge can cause the game to crash.