All forms of damage in Crypt of the NecroDancer are classified by damage types. There are 3 damage types: Normal, Piercing and Phasing.
Normal Damage is the most common type of damage in the game. It is the damage type of attacks of all monsters, traps, spells, bombs, special equipment (Holy Water, Boots of Pain, Boots of Lunging and Infernal Torch) and almost all weapons. It doesn't have any specific traits.
Piercing Damage is able to damage certain enemies through their defense (e.g. Armored Skeletons' shields).
Piercing does its damage through the defense of the following monsters:
Phasing Damage can damage all enemies without any restrictions. It can, for example, damage Fake Walls without retreating or damage Wights inside of walls.
Phasing is able to do everything that piercing damage can do, as well as damage the following monsters with no limitations:
Ghosts; Chest Mimics; Moles; Tar Monsters; Wights; Fake Walls; Ghasts; Cauldron Mimics; Ghouls; Spiders; Gargoyle Mimics; File:Placeholder.png Octoboss; seated King Conga; Dead Ringer; Electric Zombies; Lightning Mages' lightning orbs; petrified Gorgons; Crate Mimics; Barrel Mimics; Shrine Mimics; File:Placeholder.png Fortissimole.