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:

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

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.

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.