Mom's dismembered leg is called down to deal 300 damage to anything it stomps. It will always stomp on the enemy with the most health. If used in an empty room or during the fight with Mom, it will stomp Isaac instead.
Teleports Isaac to the Shop. If there is no Shop, this will act as a random teleport. If the Shop has not yet been accessed, this card will unlock the door without requiring a key (as long as the player exits through the main entrance).
Teleports Isaac to the Treasure Room. If there is no Treasure Room, this will act as a random teleport. Randomly chooses a Treasure Room on Curse of the Labyrinth. If the Treasure Room has not yet been accessed, this card will unlock the door without requiring a key (as long as the player exits through the main entrance). If there is a Planetarium, teleports Isaac there instead.
XVIII - The Moon
May you find all you have lost
Teleports the player to the Secret Room. This card will open one random wall once inside the Secret Room, so you can leave even if you don't have any bombs available. Does not work in Greed and Greedier mode.
These cards share the same names as their counterparts (barring the question marks at the end of their names), but have the sprite upside-down, the narrator sound clip reversed, and give different effects.
Teleports Isaac into an extra Boss Room from the boss pool two floors deeper than the current floor. The boss will drop a reward, but the room has no trapdoor, so Isaac cannot enter the next floor. The room has an exit door, which leads Isaac back to where he used IV - The Emperor?.
Clones all pickups and chests in a room (including Shop pickups; the clones can then be picked up for free). Cloned chests will contain exactly the same type of items: if the original contains a pickup, so will the clone; the same is true for collectibles. Cannot clone other Jera runes and trinkets.
Deals 40 damage to all enemies in the room. Consumes all pickups in the room and turns them into Blue Flies and Spiders. Consumes all pedestal items in the room and turns them into random stat upgrades. No effect on shop items.
It still glows faintly
Activates a random, weak rune effect: Algiz grants a 3 second shield, Ansuz reveals the map up to 3 rooms away, Berkano gives 1 blue fly and spider, Dagaz gives half a soul heart, Ehwaz makes a trapdoor, Hagalaz destroys some rocks, Jera duplicates one pickup and Perthro rerolls one item.
Soul Stones are all unlocked by beating both Hush and Boss Rush as their respective Tainted character. They count as runes for the purposes of duplication with Clear Rune, and Rune Bag and other sources for generation.
Isaac dies, and is immediately revived at half a heart remaining in the same room, with some invincibility time. The soul stone is automatically used upon taking fatal damage, functioning as a minimal extra life.
Isaac "dies" and turns into a ghost (similar to The Lost) for the current room, with all The Lost's benefits and weaknesses. He returns to normal upon leaving the room. Does not allow you to take devil deals for free. Does not allow you to open the door to Mausoleum for free. The Holy Mantle effect gained from this can be stacked with multiple uses.
Spawns The Forgotten as a temporary secondary character, controlled at the same time as Isaac. He dies if his three bone hearts run out, with no further consequence, and disappears when Isaac leaves the room.
Spawns Esau as a temporary secondary character, controlled at the same time as Isaac. He dies if his health runs out, with no further consequence, and disappears when Isaac leaves the room. Esau also has items equal to the number of items the player who spawned him has.
These are items other than cards and runes (and pills) that take up the consumable slot. When on the ground, each of these items are uniquely identifiable by their respective icon. These consumables cannot be replicated by either Blank Card or Clear Rune, and Tarot Cloth has no effect on them.
Using the Blank Card with the ? Card teleports the player to the I AM ERROR room of the current floor. This consumes both the Blank Card and the ? Card.
The Empress card's effect can be stacked with multiple uses of the same card (including uses by Blank Card), and also stacks with the Whore of Babylon.
The damage bonus is the number of uses squared, e.g. +1.5 * 4 * 4 damage for using the card via a Blank Card, with Tarot Cloth and Car Battery equipped.
The Devil card's effect does not stack with multiple uses, nor does it stack with The Book of Belial. It also does not increase the chance of a Devil or Angel Room appearing when used like with the Book of Belial.
After unlocking It Lives, Devil or Angel Rooms in II, Utero II, and Scarred Womb II no longer contain trapdoors and instead have their normal contents.
Using The Joker card can allow Isaac to encounter Devil Rooms or Angel Rooms on floors they otherwise cannot appear on.
If you use the Strength card with only Soul, Black, or Bone Hearts left, and lose the non-Red Hearts while in the same room, you retain the full Red Heart container that Strength grants after you leave.
The foot summoned by The High Priestess can destroy rocks and open doors, including the entrance to Secret Rooms.
The damage dealt by The High Priestess counts as explosion damage, meaning it will not damage Isaac when possessing Host Hat or Pyromaniac.
Using the Strength card as ??? will give you a permanent Soul Heart instead of a temporary one. When Keeper has only one Coin Heart, he can use the Strength card to gain a second one which is also permanent.
While Curse of the Maze is active, The Fool, Moon, Hermit, and Stars cards may fail and leave the player in a different room than intended. The Joker card still works normally.
Using the Temperance card can, in rare cases, spawn the Blood Donation Machine directly on the player, forcing them to use it once. Caution should be taken when using Temperance as The Lost (or when on half a heart of health), as this will instantly kill the player regardless of the Holy Mantle.
All teleportation cards except The Fool are unavailable in Greed Mode.
Rune Shards spawn in place of a Rune that hasn't been unlocked yet. Once all Runes are unlocked, Rune Shards no longer appear.
Leaving Trinkets in a Boss Room or a Treasure Room will transform them into a Cracked Key when on the Ascent to Home, if the Red Key is unlocked.
Once Mother is defeated, a unique marked skull that will spawn on II or XL. When destroyed, it will always drop The Fool card (Or an identified Telepills if Little Baggy has been picked up).
Using Soul of The Lost and then beating a boss for a completion mark within the same room will not count as a completion mark for The Lost. Instead, the completion mark and achievement will go to the character who used the soul stone.
Esau spawned using Soul of Jacob and Esau spawns with random items based on the pools of the items that Isaac currently holds.
Using The Fool? while having all empty heart containers with soul hearts will cause the soul hearts to all be dropped on the ground, killing the player.
The runes and their names ingame are based on the Elder Futhark alphabet system and its reconstructed Proto-Germanic names. In popular culture, runes often signify that something is in some way magical.
IX - The Hermit?'s effect was based directly on the Rune of Fehu from Antibirth. No other Antibirth rune was adapted into Repentance.
The Suicide King card is a nickname for the King of Hearts, referred to as such because its artwork depicts a king who seems to be sticking a sword into his own head.
The Get out of Jail Free card is a reference to a card with the same name that appears in the table game Monopoly.
The "A Card Against Humanity" card is a reference to the card game Cards Against Humanity.
Ancient Recall, Era Walk, Huge Growth, and Chaos Card are all based on cards from Magic: The Gathering.
The Chaos Card is a reference to the card "Chaos Orb", which also instantly destroys enemies that it touches.
The "Ancient Recall" card is a reference to the card "Ancestral Recall", which also draws three cards.
The "Era Walk" card is a reference to the card "Time Walk", which allows players to take an extra turn.
The "Huge Growth" card is a reference to the card "Giant Growth", which buffs creatures summoned in the game. Its message might be a reference to the card "Become Immense", a card with a similar effect to Giant Growth.
Rune of Hagalaz will open Secret Room doors in L-shaped rooms.
Entering a trapdoor created by Rune of Ehwaz on Corpse II will result in a black screen. Continuing after this will result in the floor restarting. Completion mark for Mother will not be received even if you have defeated her prior to entering the trapdoor.
Using IV - The Emperor? on ??? (floor) and defeating the extra boss will validate the completion mark for Hush.
Using IV - The Emperor? on Caves 2 will teleport Isaac to the Mom fight, which will not spawn an exit door, resulting in a softlock.
If the Esau spawned by Soul of Jacob and Esau spawns with Birthright, the game will instantly crash.
Using III - The Empress? as Keeper will not grant extra heart containers, but will permanently remove two when the effect wears off.
Using III - The Empress? as ??? will leave him at one half soul heart when the effect wears off.