Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki
Seeing   Double
Character Jacob appearance.png
Full red heartFull red heartFull red heartFull red heartFull soul heart
Table dividing line 1.png
Challenge Number
Starting Items
Jacob: 15►20/20 20/20
Esau: 15►20/20 20/20
15►X-Ray Vision X-Ray Vision
Available Rooms
Item Pool Treasure Room.png: no          Item Pool Shop.png: yes
Boss Mom's Heart portrait.png
Unlock Method

Seeing Double Defeat Mother

Added in Repentance

Seeing Double is challenge #40. The goal is to defeat Mom's Heart. This challenge is unlocked by defeating Mother.


Otherwise a very standard run, the challenge comes from every single enemy and boss placed naturally in rooms (as opposed to being spawned later) being doubled. Due to the high enemy density damage may prove difficult to avoid in some rooms. It is recommended for oneself to be already familiar with the gameplay of Jacob and Esau prior to attempting this challenge.


  • While room clearing items like 15►Toxic Shock Toxic Shock and items synergizing well with 15►20/20 20/20 such as 15►Jacob's Ladder Jacob's Ladder can be incredibly useful, obtaining them will be difficult with no spawning Treasure Rooms.
  • As Esau begins the challenge with 15►X-Ray Vision X-Ray Vision, Secret Rooms are instantly revealed, which may provide Jacob and Esau with helpful resources.
  • As libraries are able to spawn in this challenge, they can be a valuable resource. 15►The Bible The Bible can help with protecting one of the brothers as well as instantly killing both Mom and Mom's Heart, 15►Book of Virtues Book of Virtues will create helpful wisps in combination with other books (e.g. 15►Book of Shadows Book of Shadows), and 15►Book of Revelations Book of Revelations will help sustain either brother's health.
  • As in most challenges, Angel and Devil Rooms can help make up for a lack of treasure rooms, though gaining access to them may be difficult due to the nature of the challenge.
    • Using 15►Genesis Genesis will remove items for both Jacob and Esau, but will only produce an amount of items equal to the inventory of the brother who activated the item. However, it will grant both an additional 20/20, resulting in the pair firing 3 tears per shot with no further damage down. If obtained, it is thus recommended to use Genesis as early as possible in the run to avoid losing too many items.
  • It may be wise to keep Silver Dollar Silver Dollar if found, as the Shops it will spawn in Chapter 4 can be incredibly useful.
  • 15►Eraser Eraser is an extremely powerful item for this challenge that can be found in Shops, as permanently erasing common enemies can help tremendously.
  • Mapping effects such as 15►The Compass The Compass or 15►The Mind The Mind can help quickly navigate through levels and avoid unnecessary risks.
  • Teleportation items such as 0 - The Fool 0 - The Fool, 15►Teleport! Teleport!, or Telepills can be used to quickly escape dangerous situations or skip rooms altogether. 15►Glowing Hour Glass Glowing Hour Glass may also be used to return to the previous room and revert any possible health loss.
  • Room clearing effects are particularly powerful in this challenge:
    • 15►The Necronomicon The Necronomicon/XIII - Death XIII - Death will instantly clear more dangerous rooms.
    • The Ace of Hearts Ace of Hearts and other Ace cards will instantly clear rooms with large amounts of monsters, producing numerous pickups in the process.
    • II - The High Priestess II - The High Priestess can be an effective boss killer, greatly damaging or eliminating one or both bosses.
    • Chaos Card Chaos Card, if thrown correctly, can instantly kill numerous troublesome bosses and enemies in a single throw.
  • Enemies and bosses in Challenge Rooms are not doubled, as they are not spawned when Isaac initially enters the room. This makes it worth considering to clear them for extra pickups and items.


Unlockable achievements[]