Cards are useable items that have vairty of effects that can change the outcome of a run greatly. Cards can be found almost everywhere in the game and can be dropped by enemies as well. There are two type of cards Tarot and Suit/Joker cards, when on the ground you can only tell if the card is Tarot (brown) or Suit (red) but not which card from the type until you pick it up.
| Name | Effect |
| 0 The Fool | Transports your back to the starting room of the floor. |
| I The Magician | Turns your tears into homing tears for the room. |
| II The High Priestess | Summons Mom's Foot to stomp a enemy. This card can one shot early bosses but if this card is used in a room with no enemies or used on Mom it will go after the player. |
| III The Empress | Turns you into Whore of Babylon state (+ 2 Damage and + 1 Speed) until you leave the room. |
| IV The Emperor | Transports you to the Boss Room, if used in the boss room you will restart the fight. |
| V The Hierophant | Spawns two spirit hearts. |
| VI The Lovers | Spawns two red hearts. |
| VII The Chariot | Puts you into a state as if you used My Little Unicorn which makes you invincibile and you hurt on contact. |
| VIII Justice | Spawns one random type of bomb, key, heart and coin. |
| IX The Hermit | Transports you into the shop without needing to use a key. If you are already in the shop or there is no shop on the floor then it will transport you to a random place on the floor. |
| X Wheel of Fortune | Summons a Slot Machine. In Wrath of the Lambs if can also summon a Fortune Telling Machine. |
| XI Strength | Has the same effect as a Magic Mushroom making you have more damage and more health until you leave the room. |
| XII The Hanged Man | The card turns you into a floating head which can float over objects until you leave the room. |
| XIII Death | Deals damage to all enemies in the room in the same way as the Necronomicon. |
| XIV Temperance | Summon a Blood Donation Machine. |
| XV The Devil | Increases your damage for the room in the same way as Book of Belial. |
| XVI The Tower | Spawns six troll bombs throughout the room in the same way as the Anarchist's Cookbook. |
| XVII The Stars | Will teleport you into a Treasure Room, if your on a XL floor it will transfer you into one of them and if there is no Treasure Room it will teleport you randomly. |
| XVIII The Moon | Will teleport you into a secret room and will have one opening to connect to another room. |
| XIX The Sun | When used it completly heals you, damages all enemies in the room and revels the whole map. |
| XX Judgement | Spawns a Begger, in Wrath of the Lamb it can also summon a Devil Begger. |
| XXI The World | It will show the whole map of the floor. |
| 2 of Heart | Will double the amount of filled heart containers up to full health. This does not work when you only have spirt hearts. |
| 2 of Spades | Doubles the amount of keys you have, if you have none you get 2. |
| 2 of Clubs | Doubles the amount of bombs you have, if you have none you get 2. |
| 2 of Diamonds | Doubles the amount of coins you have, if you have none you get 2. |
| The Joker | When used you will be transported to the Devil Room, when you exit it will bring you back your starting room of the floor. In Wrath of the Lamb it can also lead you to the Angel Room. |
