Defense

For defense mechanics, refer to Defense on the vanilla wiki.

Defense is a player statistic that determines how much damage can be taken per hit. The damage the player takes is reduced by half / three quarters / all of their defense value. Defense can be increased by equipping armor and accessories, or temporarily boosted by various buffs.

Some forms of damage are impossible to reduce through defense. Damage from health-draining debuffs like Plague or drowning in water are not reduced by defense. Damage taken from lava, however, can be reduced through defense.

Damage Reduction

Main Article: Damage reduction

Damage reduction (DR) is a stat alongside defense that decreases damage that both the player and other NPCs take based on a percentage. The player can boost their damage reduction with certain accessories, although it scales diminishingly as more damage reduction is gained.

Defense Boosts

For defense granted by armor pieces and their set bonuses, see here.

Items

Item		Defense	Notes
	Aquatic Emblem	+0 to 50	Gradually builds up when submerged in liquid
	Sand Cloak	+2
		+6	While in the dust veil
	The Community	+2 to 10	Depending on bosses killed
	Marnite Repulsion Shield	+2
	Shield of the Ocean	+2
		+5	When submerged in liquid
	Wulfrum Controller	+3	For each existing Wulfrum Droid
	Corrosive Spine	+4
	Crown Jewel	+4
	Ornate Shield	+4
	Regenator	+4
	Stress Pills	+4
	Brittle Star Staff	+5	For each orbiting Brittle Star
	Occult Skull Crown	+5
		+14	When Weak debuff is active
		+15	When Darkness debuff is active
		+30	When Armor Crunch, Blackout, or Confused debuff is active
		+40	When Ichor debuff is active
		+50	When Obstructed debuff is active
		+25%	When Broken Armor debuff is active
	Gladiator's Locket	+5
	Corrupt Flask	+6	While in The Corruption
	Crimson Flask	+6	While in The Crimson
	Giant Shell	+6
		-3	For 5 seconds after taking damage
	Infected Jewel	+6
		+16	While any debuff is active
		+5	For each additional debuff the player has
	Shield of the High Ruler	+6
	Bloody Worm Scarf	+7
	Bloody Worm Tooth	+7
	Asgard's Valor	+8
	Radiance	+8
		+20	While any debuff is active
		+8	For each additional debuff the player has
	The Absorber	+10
	Archaic Powder	+10	While in the Underground, Cavern, and The Underworld
	The Camper	+10
	Dark Sun Ring	+10
		+10	During a Solar Eclipse
		+20	At night
	Elysian Aegis	+10
	Frost Barrier	+10
	Rover Drive	+10	When the protection matrix is active
	Shattered Community	+10
	Asgardian Aegis	+12
	Rampart of Deities	+12
	Laudanum	+14	When Weak debuff is active
		+15	When Darkness debuff is active
		+30	When Armor Crunch, Blackout, or Confused debuff is active
		+40	When Ichor debuff is active
		+50	When Obstructed debuff is active
		+25%	When Broken Armor debuff is active
	Giant Tortoise Shell	+15
		-10	For 5 seconds after taking damage
	Profaned Soul Crystal	+15	At night or when submerged in water or honey
		-15	At day or when submerged in lava
	Tarragon Wings	+15	While equipping a full set of Tarragon armor
	Yharim's Gift	+15
	Frost Flare	+20	When below 50% health
	Ursa Sergeant	+20
	The Sponge	+30	When the barrier is active
	Draedon's Heart	+48
	Bloodflare Core	Up to -50%	When the player is hit depending on amount of damage taken

Buffs and debuffs

Buff/Debuff		Defense	Notes
	Reaver Rage	+5
	Tequila	+5	During the day
	Mushy	+6
	Spirit Defense	+6
	Hallowed Defense	+8
	Crimson Effigy	+10
	Moonshine	+10
	Phantomic Shield	+10
	Tequila Sunrise	+10	During the day
	Afflicted	+13
	Encased	+30
	Grax Boost	+30
	Crumbling	-10
	Irradiated	-10
	Armor Crunch	-15
	Vulnerability Hex	-20
	Wither	-20
	Grape Beer	-3%
	Bloody Mary	-4%	During a Blood Moon
	Fab	-5%
	Rum	-5%
	Vodka	-5%
	Whiskey	-5%
	Margarita	-6%
	Star Beam Rye	-6%
	White Wine	-6%
	Caribbean Rum	-10%
	Cinnamon Roll	-10%
	Everclear	-30%

Armor Penetration

Armor penetration is a statistic that reduces the defense of the player's targets. For instance, a Purple Slime normally has 6 defense. If the player has 5 armor penetration and attacks the slime, then the slime will take damage as if it only had 1 defense instead.

Source		Armor penetration bonus	Condition
	Wulfrum Blunderbuss	3	Always
	Badge of Bravery	5	Melee
	Tin armor	5	Set bonus
	Marnite Obliterator	5	Always
	Experimental Wulfrum Fusion Array	10	Always
	Filthy Glove	8	When performing stealth strikes
	Marnite Deconstructor	10	Always
	Sand Shark Tooth Necklace	10	Always
	Reaper Tooth Necklace	15	Always
	Omega Blue armor	15	Set bonus
	Electrician's Glove	8	When performing stealth strikes
	Nanotech	15	When performing stealth strikes

Defense Reduction

Several weapons can permanently lower an enemy's defense on hit. These defense reduction effects cannot stack with themselves or each other, unless marked with the + symbol.

Source		Defense Reduction
	Earth	+1
	Grand Guardian	+1
	Majestic Guard	+1
	Apoctolith	15
	Anti-materiel Rifle	25

Vanilla changes

Items with their defense values changed:

Item		Vanilla	Calamity	Notes
	Adamantite armor	0	≤15	While continuously dealing damage.
	Angel Wings	0	10
	Ankh Shield	4	8
	Beetle Wings	0	10	While equipping the Beetle armor set with Beetle Shell.
	Cobalt Shield	1	4
	Fairy Boots	0	10	When Fairies are nearby.
	Frozen Shield	6	10
	Frozen Turtle Shell	0	6
	Gladiator armor	0	3
	Hallowed Greaves	11	13
	Hallowed Plate Mail	15	18
	Hero Shield	10	15
	Leaf Wings	0	5	While equipping a full set of Tiki armor.
	Magma Skull	0	4
	Molten Skull Rose	0	8
	Mothron Wings	0	5
	Obsidian Shield	2	6
	Obsidian Skull	1	2
	Obsidian Skull Rose	0	4
	Orichalcum Breastplate	13	16
	Orichalcum Headgear	4	6
	Orichalcum Helmet	7	10
	Orichalcum Leggings	10	14
	Orichalcum Mask	19	22
	Paladin's Shield	6	8
	Palladium Breastplate	10	13
	Palladium Headgear	3	5
	Palladium Helmet	5	8
	Palladium Mask	14	15
	Palladium Leggings	8	11
	Shackle	1	3
	Shield of Cthulhu	2	3
	Spectre Wings	0	10	While equipping the Spectre armor set with Spectre Hood.
	Steampunk Wings	0	8

Defensive accessory modifiers now scale with progression:

Modifier	Hard	Guarding	Armored	Warding
Vanilla	+1	+2	+3	+4
Hardmode	+2	+3	+4	+5
Post-Moon Lord	+3	+4	+5	+6
Post-Devourer of Gods	+4	+5	+6	+7

• Ironskin buff now increases defense by 10, 12, and 14 after defeating the Wall of Flesh, Moon Lord, and The Devourer of Gods respectively instead of always increasing defense by 8.
• The Tipsy debuff now reduces defense by 10% instead of a flat reduction of 4.
• Sharpening Station's armor penetration value has been nerfed from 12 to 5.