Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki

In The Void, locating which boss room may contain Delirium is a surprisingly simple process, it requires imagining the boss rooms as being 2x2 boss rooms. If the 2x2 boss room would be able to exist where it is without having doors to any other rooms, then it is very likely that boss room will contain Delirium.

We will break down this process by using this map as an example case.

Locating Delirium Full Map.png

Example 1[]

Locating Delirium 1.png

Here we see a small cluster of boss rooms very near to each other.

Locating Delirium 1 Marks.png

By drawing out what one of these boss rooms would look like as a 2x2 boss room, we can get a clear picture of where this room would be connected by doors to if this was the case. The door the boss room already has is indicated with green here, while doors that would show up if this was a 2x2 room are marked in red.

Locating Delirium 1 Final.png

Because this room would have multiple doors instead of just one, it is impossible for this room to contain Delirium.

Example 2[]

Locating Delirium 2.png

This boss room is out near the edge of the map.

Locating Delirium 2 Marks.png

When drawing the outline of a 2x2 boss room here, we can see that this room would only have a single door even if it was a 2x2 boss room.

Locating Delirium 2 Final.png

Because this room would only ever have a single door, we can determine that this room is very likely (though not guaranteed!) to contain Delirium.

Example 3[]

Locating Delirium 3.png

Much like example 2, this room is near the edge of the map. However, there is a small trick going on here that may not be obvious at first glance.

Locating Delirium Full Map Grids.png

This is the full map but with every square numbered. Maps have a maximum size of 13x13; rooms cannot go beyond this limit.

Locating Delirium 3 Marks.png

A 2x2 room can be drawn here without any connections to other rooms, but this would go past the 13x13 limit.

Locating Delirium 3 Final.png

Because of this easy-to-miss detail, this room cannot contain Delirium.

Additional Notes[]

  • It is possible for a floor to contain multiple possible Delirium rooms, though through the above methods you can rule out the rooms which can never contain Delirium.
  • If a boss room on the top or right edge of the map causes the full-sized map to be offset as though it were trying to display a room larger than 1x1, that boss room belongs to either Delirium or Mr. Fred.


SmallIsaac.pngChaptersSmallIsaac.png
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Optional Chapter 5 Chapter 6 Endgame
Normal and hard modes only Stage Basement icon.png Stage Caves icon.png Stage Depths icon.png Stage Womb icon.png Stage Sheol icon.png
Sheol


Stage Cathedral icon.png
Cathedral
Stage Dark Room icon.png
Dark Room


Stage Chest icon.png
The Chest
The Basement The Caves The Depths The Womb
Added in Afterbirth Added in Afterbirth †
Stage Cellar icon.png Stage Catacombs icon.png Stage Necropolis icon.png Stage Utero icon.png ??? Stage The Void icon.png
The Cellar The Catacombs Necropolis Utero ??? The Void
Added in Afterbirth Added in Afterbirth Added in Afterbirth Added in Afterbirth
Stage Burning Basement icon.png Stage Flooded Caves icon.png Stage Dank Depths icon.png Stage Scarred Womb icon.png
Burning Basement Flooded Caves Dank Depths Scarred Womb
Added in Repentance Added in Repentance Added in Repentance Added in Repentance Added in Repentance
Stage Downpour.png Stage Mines icon.png Stage Mausoleum icon.png Stage Corpse icon.png Stage Home icon.png
Downpour Mines Mausoleum Corpse Home
Added in Repentance Added in Repentance Added in Repentance
Stage Dross icon.png Stage Ashpit icon.png Stage Gehenna icon.png
Dross Ashpit Gehenna
Added in Afterbirth
Greed and greedier modes only
Added in Afterbirth Added in Afterbirth
Stage Basement icon.png Stage Caves icon.png Stage Depths icon.png Stage Womb icon.png Stage Sheol icon.png The Shop Ultra Greed
The Basement The Caves The Depths The Womb Sheol The Shop Ultra Greed
The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth
Achievements Achievements Attributes Attributes Bosses Bosses TarotCard.png Cards and Runes Challenges Challenges Chapters Chapters
Characters Characters MainPageBabies.png Co-op Items Items Item pools Item pools Monsters Monsters Objects Objects
Pickups Pickups Pills Pills Rooms Rooms Seeds Seeds Transformations Transformations Trinkets Trinkets