? Card

? Card is a special card added in The Binding of Isaac: Afterbirth.

Effect

 * Replicates the effect of Isaac's activated collectible.
 * Single-use items, such as, will not replicate but instead activate and disappear.
 * Single-use items do not disappear after using ? Card, allowing for potential multiple uses of the items.

Interactions

 * : Does not influence the card's effect, activating the active item only once.
 * : Expends both the card and all charges with no additional benefit.

Synergies

 * : Teleports the player to the I AM ERROR room of the current floor. This will consume both the Blank Card and the ? Card. If done on or, will instead spawn an I AM ERROR shopkeeper.
 * : Since the card replicates the effect of moving back one room to the previous state, you keep the card having not used it as an item until the room later. This effectively gives you charge-free uses of the Glowing Hour Glass.
 * The card is no longer refunded.
 * : ? Card is used twice, giving the active item the same effect as if you had Car Battery.
 * : Duplicates all pedestal items and pickups in the room, without expending Diplopia.
 * If used with another ? Card dropped on the floor in the room, allows for infinite duplication.
 * : Causes the Alabaster Box to pay out with two angel room items without destroying the item or depleting any of it's current charges.
 * + : ? card can be duplicated with the D1, allowing for single use items to be repeatedly used on effectively a 4 room charge.

Trivia

 * The interaction with Blank Card presents a paradox, as Blank Card and ? Card try to replicate the effects of each other. This would result in an endless loop, so a special case was put in.
 * The Blank Card interaction is one of the four reliable ways to reach the I AM ERROR room in game, alongside in certain circumstances, using  to go beyond the 13x13 level grid, and.
 * Before Booster Pack, was limited to 5 uses, and uses of the ? Card counted against that limit.