Pandora's Box Effects

Two simple tables you can refer to when finding Pandora's Box in your run, plus some information and intricacies of using it. Covers Normal/Hard difficulties as well as Greed/Greedier mode.

Just a little something for myself, since I always find myself having to open a tab of the Isaac wiki whenever I find Pandora's Box. Might as well publish it, since some existing guides on Steam seem to be missing information or DLC changes. Side note: Favouriting a guide will mean that it will always show up first in the Guides subcategory of your Steam in-game overlay (the shift+tab menu), so if you wish to have quick access to this guide or some other helpful guide, give it a favourite!

Effects in Normal/Hard Mode:

Chapter Title	Alt Floors in this Chapter	Floor Number	Rewards
Chapter 1: The Basement	Basement, Cellar, Burning Basement, Downpour, Dross	1st or XL floor	2 soul hearts
-	-	2nd floor	2 bombs and 2 keys
Chapter 2: The Caves	Caves, Catacombs, Flooded Caves, Mines, Ashpit	1st or XL floor	1 Boss Room item
-	-	2nd floor	1 Boss Room item and 2 soul hearts
Chapter 3: The Depths	Depths, Necropolis, Dank Depths, Mausoleum, Gehenna	1st or XL floor	4 soul hearts
-	-	2nd floor	20 coins
Chapter 4: The Womb	Womb, Utero, Scarred Womb, Corpse	1st or XL floor	2 Boss Room items
-	-	2nd floor	The Bible
Chapter 5a: Cathedral	n/a	n/a	1 Angel Deal item and 1 eternal heart
Chapter 6a: The Chest	n/a	n/a	1 penny
Chapter 5b: Sheol	n/a	n/a	1 Devil Deal item and 1 black heart
Chapter 6b: Dark Room	n/a	n/a	Unlocks Moving Box in Afterbirth+, otherwise nothing
??? (Blue Womb)	n/a	n/a	Nothing
The Void	n/a	n/a	Nothing
Final Chapter: Home	n/a	n/a	Red Key

Effects in Greed/Greedier Mode:

Chapter Title	Alt Floors	Rewards
Chapter 1: The Basement	Basement, Cellar, Burning Basement	2 bombs and 2 keys
Chapter 2: The Caves	Caves, Catacombs, Flooded Caves	1 Boss Room item and 2 soul hearts
Chapter 3: The Depths	Depths, Necropolis, Dank Depths	20 coins
Chapter 4: The Womb	Womb, Utero, Scarred Womb	2 Boss Room items
Chapter 5: Sheol	n/a	1 Devil Deal item and 1 black heart
Chapter 6: The Shop	n/a	1 penny
Final Chapter: Ultra Greed	n/a	1 penny

Important Information

The basics of Pandora's Box (if you're already familiar with the item, you can skip this)

• Pandora's Box [bindingofisaacrebirth.fandom.com] is a one-time use item that takes up the Active slot. It is unlocked by beating Dark Room as Lazarus for the first time, and once unlocked, it will show up in the Red Chest and Shop item pools on future runs as well in as the Greed/Greedier mode shops. Its one-time use nature means it will disappear after the first use, so decide carefully when to open it up!
  
• It will spawn a different combination of pickups or pedestal items depending on what your current floor and chapter are (you can hold tab to see what the current stage is called; Basement I, Utero II, Cathedral, etc.). This means you can carry the box with you to future floors if you wish to take advantage of a certain floor's effects, all of which are listed in the section below. Keep in mind your active item slot will be occupied by the box until you leave it behind or use it, so unless you have the Schoolbag [bindingofisaacrebirth.fandom.com] passive item or use the Moving Box [bindingofisaacrebirth.fandom.com], you won't be able to keep any other active items when doing this method.

The finer details of Pandora's Box

• When on an XL Floor because of Curse of the Labyrinth, refer to the first floor of your current chapter.
  
• The Afterbirth passive item Car Battery [bindingofisaacrebirth.fandom.com] does not double the reward gained from using Pandora's Box, no matter what floor you're on.
  
• With the Repentance DLC loaded, the consumable ? Card [bindingofisaacrebirth.fandom.com] will not consume single use active items such as Pandora's Box, meaning you can consume the card to gain a reward for the current floor without consuming Pandora's Box. Keep in mind that if you do not have Repentance active/installed, using the ? Card will just consume the box as if you had used it normally.
  
• With one exception, Pandora's Box calls items from a set item pool when used on floors that would make it spawn a pedestal item, e.g. Boss reward pool, Devil deal pool or Angel deal pool. That said, if the item pool Pandora's Box tries to use has already been exhausted, it will instead spawn an item from the Treasure Room item pool. You will rarely be in a situation where an entire item pool has been exhausted, though, so don't try to incorporate this into your strategy when you find a box.
  
• The exception to the item pool rule listed above is when the user is holding the Strange Key [bindingofisaacrebirth.fandom.com] in their trinket slot (Repentance trinket, unlocked by beating Cathedral, The Chest, Sheol and Dark Room as Tainted Eve ). With the trinket in tow, the current floor's listed effect is ignored completely and 6 items from randomly selected pools will be spawned instead, consuming both the box and the Strange Key.
  
• It is important to note that when Pandora's Box spawns items, the spawned items are placed on pedestals around the player and remain there. Therefore, if the box spawns 'bad' items or items you don't wish to take, you can choose not to pick them up and instead reroll or void absorb them if given the chance (a good strategy if you lack the necessary items is to open the box in a room with a reroll machine already inside). However, remember that even though Pandora's Box pulls from the pools of either Boss Rewards, Angel Deals or Devil Deals, rerolling an item pedestal pulls from the pool of the room they're currently in (for non-special rooms, the Treasure Room pool is used), so you can't expect to reroll an item into another of the same pool unless you're in the same room that pool exists in.

An example of ??? finding Pandora's Box on the first floor curse room.