Hearts are Pick Ups that replenish the player's health. If a player runs out of red hearts (or in ??? 's case, soul hearts) they will die and view their Last Will, unless the player has Dead Cat, the Ankh or a 1UP.
If Isaac enters a room with a half heart, there will be urine (In Eve's case, blood) behind him.
Red Hearts are divided into half hearts and full hearts. These have an equal chance of spawning. Half hearts heal 1/2 heart container, while full hearts heal a whole container. They can be found after a boss battle or killing all the enemies in a room. Certain Items can give the player additional heart containers, like the Holy Grail or Rotten Meat.
Full Hearts cost 3 coins in the shop (2 when on sale.)
Soul hearts look similar to regular hearts but are blue with a faint white outline. They are a rarer form of heart that may randomly appear instead of red hearts, or can be found in shops. They have a high chance of spawning when a Tinted Rock is blown up.
Soul hearts function as a form of armor for Isaac, absorbing damage that he takes so that he does not lose any HP. Once a soul heart is obtained, all normal damage removes soul hearts until their supply is depleted. Each soul heart adds a full container and can take a full heart's worth of damage before being lost. Soul hearts may be increased beyond the maximum visible level of HP and will still be counted even though they are not shown. The very last half soul heart a player has will absorb all incoming damage while breaking, so taking a full heart of damage with one half soul heart left breaks the soul heart but does not take away red hearts. ??? uses soul hearts entirely as his health, and any additional health he gains through items will automatically be turned into soul hearts.
Additionally, three soul hearts may occasionally be spent in the Devil Room to purchase an item. Soul hearts in the shop cost 5 coins, 3 when on sale. 1/2 soul hearts do not exist as a pickup in-game, even in the Wrath of the Lamb DLC.
A heart has a chance of spawning as a soul heart based on these rules:
- 10% chance for it to become a soul heart.
- If playing as Eve, an additional 6.25% chance.
- If holding the Mom's Pearl trinket, an additional 10% chance.
- If holding the Mitre, an additional 50% chance.
Note that the extra chances for a soul heart to spawn from Mom's Pearl and the Mitre are consecutive rather than additive, so (not as Eve) with Mom's Pearl, your chance would be 1 - (0.9 * 0.9) = 19% (rather than 20%) and with the Mitre your chance would be 1 - (0.9*0.5) = 55% (rather than 60%).
In the expansion, eternal hearts can also spawn in the place of a regular heart. They act as a Half Red Heart until you find 2 of them, or the player moves onto the next floor (also works when the Forget Me Now is used), in which case it will turn into a full red heart container. Eternal Hearts alone are not enough to prevent death. If you have no regular hearts (from playing with ??? or using Guppy's Paw) and have an eternal heart, you will still die if you lose all soul hearts, but if you use an extra life to come back you will still have the eternal heart. Eternal Hearts can also be found in the Cathedral Super Secret Room. In fact, all hearts spawned in that room will be Eternal, which makes for good use of the Portable Slot. Unlike soul hearts, taking a full heart of damage with just an eternal heart and red hearts will remove the eternal heart and half of a red heart, not just the eternal heart.
A heart has a 2% chance of spawning as an eternal heart. The game rolls for Eternal Hearts after Soul hearts, meaning this probability is actually slightly lower.
It is possible to lose Eternal Hearts by getting hurt by enemies and Blood Donation Machines; precisely, Blood Donation Machines take Eternal Hearts before any other type of hearts, but getting hurt by an enemy takes Soul Hearts first, then Eternal Hearts, and finally, Red Hearts.
Magneto will only attract eternal hearts when health is not full (like red hearts).
Chance to find any heart pickupEdit
- Completing rooms
- Champion enemies
- Chests (1 to few)
- Slot Machines
- Shell games (2 at a time)
- Bosses (2 at the start, 1 when "Everything's Terrible" is unlocked. Extra heart is gotten from Champion forms.
- Justice tarot card (will spawn a full heart in the womb-themed top secret room and an eternal heart in the cathedral-themed top secret room)
- The Lovers tarot card (spawns two full hearts onto floor, one to either side of character)
- Little C.H.A.D. (Spawns one half heart after every two rooms)
- Charm Of The Vampire (Heals one half heart after killing 13 enemies)
- Isaac's Fork (10% of healing one half heart after every room)
- Yum Heart (heals a full heart on use, 4 room recharge)
- Bloody Penny (50% of spawning a half heart on every coin pickup)
- Womb-themed super secret room
- Shop (costs 3 coins or 2 when on sale)
Items that spawn them
- Tinted rocks (may spawn 1 or 2)
- Fortune Telling Machine (may spawn 1)
- Red Chest (may spawn 1 or 2)
- The Relic (spawns one every 5 rooms)
- The Hierophant tarot card (spawns 2)
- Squeezy (spawns 2)
Items that give them
- The Nail (6 room recharge, additional effects)
- Book of Revelations (6 room recharge, additional effects)
- Crystal Ball (6 room recharge, may give cards instead, additional effects)
- The Mark (damage increase)
- The Pact (+2 SH, damage and tears increase)
- Rosary (+3 SH, additional effects)
- Super Bandage (+2 SH and +1 HP)
- Balls of Steel Pill (2 Soul Hearts)
- Guppy's Paw (3 in exchange for a heart container)
- Cathedral-themed super secret room
- Prayer Card (6 room recharge)
- Maggy's Faith (1 at the start of each new floor)
"Maggy's Wig" - Have seven or more Heart Containers at once in a single playthrough.