Defense

Defense is a statistic that determines the decrease in damage taken per hit. The player's defense can be increased by wearing armor and accessories, and temporarily boosted/decreased by various buffs/debuffs. Enemies also have a defense statistic.

Defense cannot be reduced to below 0. Furthermore, the damage dealt to an entity will always be at least 1, regardless of defense (with the exception of a player whose multiplayer ally is wearing a Paladin's Shield).

Some forms of damage are impossible to reduce through defense, e.g. damage from damage over time debuffs like Cursed Inferno or from drowning in water. Damage taken from lava, however, can be reduced through defense.

Some items have the ability of armor penetration, which, in most cases, allows them to ignore some or all of the target's defense when calculating damage.

Players

Defense gives a flat reduction in damage, i.e. damage is reduced by a fixed amount per hit (as opposed to a multiplicative damage reduction, which would reduce damage by a percentage). It is calculated after the general ±15% damage randomization.

The formula is: net dmg = \lfloorattack dmg - def × factor\rfloor, where factor is 0.5 in Classic Mode, 0.75 in Expert Mode, and 1 in Master Mode.

Examples

Atk. dmg	Def.	Net damage
		Classic	Expert	Master
40	20	30 <floor40 - 20 * 0.5\rfloor = 30	25 <floor40 - 20 * 0.75\rfloor = 25	20 <floor40 - 20 * 1\rfloor = 20
40	30	25 <floor40 - 30 * 0.5\rfloor = 25	17 <floor40 - 30 * 0.75\rfloor = 17	10 <floor40 - 30 * 1\rfloor = 10
75	20	65 <floor75 - 20 * 0.5\rfloor = 65	60 <floor75 - 20 * 0.75\rfloor = 60	55 <floor75 - 20 * 1\rfloor = 55
75	30	60 <floor75 - 30 * 0.5\rfloor = 60	52 <floor75 - 30 * 0.75\rfloor = 52	45 <floor75 - 30 * 1\rfloor = 45

Enemies

Enemies have a defense statistic just like players do, but they do not gain more protection from defense in Expert Mode or Master Mode. They will always reduce incoming damage by 50% of their defense: net dmg = \lfloorattack dmg - def × 0.5\rfloor.

Examples

Weapon	Green Slime 0 defense	Chaos Elemental 30 defense	Paladin 50 defense	Sharkron 100 defense
Gold Broadsword 15 damage	15	1 (0)	1 (-10)	1 (-35)
Meowmere 200 damage	200	185	175	150

Boosts

Armor and accessories

A player's defense score can be increased by equipping armor and accessories. Armor usually consists of three items, granting an additional bonus if all pieces match, the set bonus, which may increase the defense score further. Some accessories grant direct defense boosts (see the following table), but all accessories can also be reforged to have defense-increasing modifiers.

See armor for detailed defense information about every piece of armor.

Item	Accessory defense
Cobalt Shield	1
Obsidian Skull	1
Shackle	1
Obsidian Shield	2
Shield of Cthulhu	2
Ankh Shield	4
Frozen Shield	6
Paladin's Shield	6
Berserker's Glove	8
Flesh Knuckles	8
Hero Shield	10

Item	Accessory defense
Moon Charm	3 (only during the night)
Moon Shell	3 (only during the night)
Moon Stone	4 (only during the night)
Sun Stone	4 (only during the day)
Celestial Shell	4 (during the day) 7 (during the night)
Frozen Turtle Shell	30 (when below 25% health)

Modifier	Defense
Hard	1
Guarding	2
Armored	3
Warding	4

Buffs and debuffs

Buffs and debuffs can temporarily alter a player's or an enemy's defense. The defense of enemies cannot be increased.

Buff/Debuff	Buff/debuff defense
Well Fed	2
Plenty Satisfied	3
Exquisitely Stuffed	4
The Bast Defense	5
Dryad's Blessing	8
Ironskin	8
Tipsy	−4
Weak	−4
Ichor	−15 / −20
Betsy's Curse	−40
Broken Armor	−50%

Armor penetration

Armor penetration is a hidden player statistic that determines the effective amount of the enemy's defense portion that is ignored when dealing damage to it. It works by increasing the damage dealt as follows:

• If the player's total armor penetration is greater than the enemy's original defense (i.e. before defense is reduced by certain debuffs), the damage is increased by half of the enemy's defense. This means that the entirety of the enemy's defense is effectively ignored (as the enemy's damage reduction by half its defense – see above – is canceled out).
• If the player's total armor penetration is lower than or equal to the enemy's original defense, the damage is increased by half of the armor penetration value. This means that any amount between nearly none and all of the enemy's defense is effectively ignored, depending on the specific values.

See below for examples.

Note that the defense-reducing debuffs Ichor and Betsy's Curse are disregarded in these calculations. All decimals are rounded down.

The following items grant armor penetration (they all stack with each other):

Item		Armor penetration
	Shark Tooth Necklace	5
	Stinger Necklace	5
	Sharpening Station	12 (for melee weapons only)
	Hive Pack	5 (for Wasp Gun only)

In addition, the projectiles of certain weapons and accessories have an own armor penetration stat, which is added to the player's armor penetration when inflicting damage upon an enemy with them:

Item		Armor penetration
	Blade Staff	25
	Dark Harvest("dark energy")	50
	Cool Whip(snowflake)	30
	Light's Bane(slash of darkness)	5
	Blade of Grass(projectile)	20
	Muramasa(slash)	5
	Bone Glove	25
	Crystal Vile Shard	10
	Nettle Burst	10
	Wasp Gun	10
	Star Cloakand its upgrades	25
	Arkhalis	20
	Weather Pain	10
	Flamethrower	15
	Elf Melter	15

Examples

Enemy	Player AP		Increased damage	Explanation
Green Slime 0 defense	0	→	0	AP ≤ defense, so increase is AP/2
	10	→	0	AP > defense, so increase is defense/2
Chaos Elemental 30 defense	0	→	0	AP ≤ defense, so increase is AP/2 (0% of defense ignored)
	10	→	5	AP ≤ defense, so increase is AP/2 (33.33% of defense ignored)
	40	→	15	AP > defense, so increase is defense/2 (100% of defense ignored)
Sharkron 100 defense	5	→	2	AP ≤ defense, so increase is AP/2 (4% of defense ignored)
	10	→	5	AP ≤ defense, so increase is AP/2 (10% of defense ignored)
	40	→	20	AP ≤ defense, so increase is AP/2 (40% of defense ignored)
	100	→	50	AP ≤ defense, so increase is AP/2 (100% of defense ignored) (This is a theoretical example, as it is impossible to attain 100 AP.)

Maximum defense

The highest possible defense can be attained using the setups described in the following sections.

 Desktop version,  Console version, and  Mobile version

The maximum possible defense is 186 / 196 / 204:

Armor (82 defense)

• Solar Flare Helmet or Hallowed Mask
• Solar Flare Breastplate
• Valhalla Knight's Greaves

Accessories (59 / 69 / 77 defense)

• Hero Shield
• Flesh Knuckles
• Berserker's Glove
• Celestial Shell
• Frozen Shield
• Paladin's Shield(Expert/Master)
• Ankh Shield(Master)

• At night, when not submerged in water
• Warding modifiers on all accessories

Buffs (25 defense)

• Ironskin
• Exquisitely Stuffed
• Dryad's Blessing
• The Bast Defense

Other (20 defense)

Guarding with the Brand of the Inferno or Sergeant United Shield

 Old-gen console version and Nintendo 3DS version

The maximum possible defense is 128:

Armor (76 defense)

• Dragon Mask
• Beetle Shell
• Beetle Leggings

Accessories (42 defense)

• Paladin's Shield
• Ankh Shield
• Moon Stone or Sun Stone
• Frozen Turtle Shell
• Celestial Stone

• At night or day (depending on Moon/Sun Stone), at low health
• Warding modifiers on all accessories

Buffs (10 defense)

• Ironskin
• Well Fed

Trivia

• Although not possible in-game, if a piece of armor were to gain a modifier, it would apply the effects just like an accessory would. For example, a set of Warding modified armor would add 12 defense total; each piece adding 4 defense to the total.
• Damage dealt by enemies is doubled in Expert Mode and tripled in Master Mode compared to Classic Mode. This means that despite the higher factors of defense in those modes, players will still take more damage than they would in Classic Mode.
• If the player somehow has negative defense, they will take more damage according to the damage taken added with half / three quarters / full amount the defense.

See also

• Damage reduction