2 Other sources of health
2.1 Soul hearts and Demon hearts
Your regular hearts aren’t the only source of health in TBoI. There are two main exceptions:
|Special Case 3: Soul hearts
|Soul hearts are grey-colored hearts that function almost exactly the same as regular hearts, with two important distinctions 1. Soul hearts always stack on top of your existing hearts (which means that they will “get hit” before your red hearts, and 2. Soul hearts are temporary: once they’re gone, they’re gone; unlike your regular heart containers that stay even if you suffer damage
Soul hearts can drop from a regular room fight, as a reward for defeating some champions. They are also granted upon pick up of the following items (note that some of these also appear in the previous table, this is no mistake)
The following items may also give you soul hearts:
- The Nail—upon use
- The Relic—gives a soul heart every 4 rooms
- Guppy’s Paw—upon use converts 1 heart container to 3 soul hearts. This can be done any number of times while you have heart containers
- Crystal Ball—sometimes, upon use
- Pandora’s Box—Only if used on the very first floor (Basement 1), the third floor (Caves 1) or the fifth floor (Depths 1)
- Sharp Straw—upon use has a chance to drop 1/2 a soul heart
- Death’s List—if all enemies in a room are killed in a particular order, it may drop a soul heart
- Dark Bum—has a chance to give you a soul heart if you let him consume red hearts
- Gimpy—has a chance to drop a soul heart upon taking damage
|Special Case 4: Demon hearts
|Demon hearts are black-colored hearts that function almost exactly like soul hearts, with the added benefit that upon disappearance you deal 400 “unblockable” damage to every enemy in the room
Demon hearts can come from the following items:
The following items may also give you demon hearts:
- Abaddon—upon pickup, removes all heart containers and gives you 6 black hearts
- The Satanic Bible—upon use
- Dark Bum—has a chance to give you a demon heart if you let him consume red hearts
- Gimpy—has a chance to drop a demon heart upon taking damage
- Pandora’s Box—Only if used on Sheol
- Maw of the Void—After holding fire for 3 seconds and releasing, it will create a black ring around Isaac that damages enemies. When defeated by this ring, enemies have a chance of dropping a demon heart
- Athame—Similar to Maw of the Void, but the black ring will only trigger upon taking damage
- Sacrificial Altar–upon use, only if you sacrifice either the Guardian Angel, Sworn Protector or Seraphim
2.1.1 Why should I care for Soul/Demon hearts?
Newbie TBoI players tend to value red hearts and heart containers as more important than Soul/Demon hearts—after all, the latter cannot be regenerated and many have been trained for years to see health as one of the most important aspects of gameplay.
But one of the major points of this guide is to teach those players that a sufficiently skilled TBoI player will often value Soul/Demon hearts above regular HP. Why, just this morning I saw episode 1302 of Ryan “Northernlion” Letorneau playing the game and passing over an HP upgrade just one room before the Final Boss. Why?
2.2 Eternal hearts and Bone hearts
Although not as important, Eternal hearts and Bone hearts are also sources of Hit Points and have their own use cases. The reason for separating these from the Soul and Demon hearts is that those are mechanically much more important for the aspiring TBoI Platinum God.
|Special case 5: Eternal hearts
|Eternal hearts are white-colored half-hearts. They always sit on top of your last red heart but before any soul or demon hearts. This means that after all soul or demon hearts are exhausted, the first hit you receive will hit the eternal heart.
Eternal hearts are a special source of HP: If you manage to get two of them in the same floor—or if you take one to the next floor—you will get an extra heart container.
|Special case 6: Bone hearts
|Bone hearts are bone-looking hearts that can hold a regular red heart inside them, acting as a sort of “shell”. An empty bone heart will resist a single hit of damage and will disappear afterwards. This also means that a full bone heart will sustain 3 hits.
Bone hearts act like a temporary heart container: a bone heart only disappears once it’s empty AND receives damage.
Due to their color and the mechanical differences, it’s common to refer to regular hearts as “red HP”. This is a crucial difference that will be discussed later in this guide.
1: Health as Hit Points
← Health in The Binding of Isaac
→ 3: Health as a test of skill