Metronome

Metronome is an unlockable activated item added in Afterbirth †.

Effect

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

Interactions

 * / Holy Card / / 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  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:
 * 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.
 * : the mushroom familiar continues to follow Isaac, but doesn't grant an extra life.
 * : the tear appearance is reset back to normal, but the tears still travel through enemies.
 * : the tear appearance is reset back to normal, but tears can still explode when they hit an enemy.
 * : the tear appearance is reset back to normal, but tears will still leave green creep on the ground.
 * : does not persist between rooms.
 * : 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.
 * : 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.
 * will permanently remove the latest item and change character.
 * granted by will persist.
 * 's rerolled stat multipliers will persist, or  will reroll all items permanently and  mimicking any of the previous also has the same effects.
 * will permanently grant the passive version of Damocles.
 * 's stat changes will persist.
 * will restart the level.
 * 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.
 * will restart the run, retaining all items.
 * 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.
 * and give no indication of extra lives, but will still work if you die in the room.
 * will not remove red hearts or grant black hearts.
 * and 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.
 * only adds a black heart and does not remove curses.
 * and do not grant bone hearts. Brittle Bones can still be used to gain permanent tears ups if bone hearts are available.
 * only adds soul hearts, no damage multiplier.
 * will only restore one red heart without setting heart containers to 1. It also gives no extra lives.
 * ,, , and allow picking up two consumables while in the room and kept outside, but using them will lose the extra slot.
 * will not grant an extra item for the next run.
 * only grants flight, no eternal heart.
 * will not identify pills, but they are still guaranteed to not be negative.
 * 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:
 * The following items have no effect:
 * Items that only spawn pickups or consumables are not mentioned separately.
 * The following items have no effect:
 * Items that only spawn pickups or consumables are not mentioned separately.

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.

Bugs
Metronome