
The Scapular allows practically free use of damage-triggered effects, as long as care is taken to keep track of the item's state and remaining health, and possibly being forced to proceed with minimal health after reaching the desired goal is acceptable.
+ The Wafer: Grants true immortality, plus one hit on the soul heart, allowing the player to get hit once before teleporting. Cursed Skull: Provided Scapular can always trigger, grants effective immortality, as the soul heart is always given before the teleport takes place. Sacrifice Rooms spikes still activate Scapular. This includes Blood Donation Machines, Devil Beggars, Hell Games, Confessionals, IV Bag, Razor Blade, Blood Rights, Dull Razor, Sharp Plug, Shard of Glass, Blood Bombs, and Blood Oath. Damage sources that count as "health donation" no longer activate Scapular. Reaching only half a heart remaining may be more difficult in Chapter 4 onwards, since all half-heart hits are upgraded to a full heart. Does not work with The Lost or Keeper, as they cannot reach the required heart value. Scapular does not charge between waves in Greed mode, though it can still be recharged by moving between rooms. If the Scapular is active and Isaac is already at his last half heart, the effect won't trigger even on fatal damage.
With Bone Hearts, the effect triggers on both half-filled and empty ones.After re-entering a room, the ability can be triggered again.Once per room, when Isaac is reduced to his last half heart (either red, soul, or black), the aura around his head temporarily vanishes and he is granted one Soul Heart.