Defense is a player statistic that determines how much damage can be absorbed per hit. On non-Expert Mode worlds, damage the player takes is reduced by half of their defense value, rounded up. In Expert Mode, damage the player takes is reduced by three-quarters of their defense value, rounded up. Defense can be increased by equipping armor and accessories, or temporarily boosted by various buffs. No attack can be reduced below 1 damage (with the exception of a player with an ally wearing the Paladin's Shield).
Some forms of damage are impossible to reduce through defense. Damage from health-draining Debuffs like Cursed Inferno, drowning in water, or colliding with a boulder are not reduced by defense.
Damage taken from lava can be reduced through defense.
Mechanics
Defense gives an arithmetic reduction in damage: i.e. damage is reduced by a fixed amount per hit (as opposed to a geometric damage reduction, which would reduce damage by a percentage).
Non-Expert Mode Formula
The formula is:
net damage = attack - (defense * 0.5)
For example:
- With 10 Defense, a 20 Damage attack is reduced by 5, resulting in 15 damage taken.
- With 21 Defense, a 20 Damage attack is reduced by 11, resulting in 9 damage taken.
Expert Mode Formula
In expert mode, the formula is:
net damage = attack - (defense * 0.75)
For example:
- With 20 Defense, a 40 Damage attack is reduced by 15, resulting in 25 damage taken.
- With 30 Defense, a 40 Damage attack is reduced by 23, resulting in 17 damage taken.
Note that in expert mode only the player's defense follows the formula. Enemies will still take the same amount of damage as in normal mode.
Enemies
Enemies have the same Defense mechanics as players. Monsters with high defense will take virtually no damage from low damage weapons (e.g. Fire Imps take 5 damage from the Minishark with Musket Balls). Accordingly, when fighting high defense monsters, high damage weapons are preferable.
Defense boosts
Here is a list of armors, accessories, and their respective defense bonuses, including any applicable set bonuses.
Damage reduction boosts
| Buff | Source | Damage reduction bonus |
|---|---|---|
 Solar Blaze |
Solar armor | 30% |
 Beetle Endurance |
Beetle armor | 15%/30%/45% |
 Paladin's Shield |
Paladin's Shield | 25% (Only active above 25% life) |
 Endurance |
Endurance Potion | 10% |
 Ice Barrier |
Frozen Turtle Shell | 0 Template:Mobile icon/ 25% (When below 50% health) Template:Pc icon |
 Warmth |
Warmth Potion | 30% (Reduces damage only from cold-themed enemies) |
| Item | Damage reduction | |
 Worm Scarf |
17% |
Armor Penetration
Template:Pc only Armor penetration is a statistic that reduces the defense of the player's targets. For instance, a Pixie normally has 20 defense. If the player has 5 Armor Penetration, then the Pixie will be taken to have 15 defense instead.
| Source | Armor penetration bonus |
|---|---|
 Shark Tooth Necklace |
5 |
 Sharpening Station |
4 for Melee Weapons only |
Notes
- The highest possible defense is 152 normally, and 160 in expert mode.
- Chlorophyte Mask，Solar Flare Breastplate and Solar Flare Leggings or Vortex Leggings - 79 defense
- Flesh Knuckles - 7 defense
- Celestial Shell - 7 defense if worn at night
- Paladin's Shield - 6 defense
- Any other two accessories that give 4 defense at night - 8 defense
- Warding modifiers on all accessories - 20 defense
- Ironskin buff - 8 defense
- Well fed buff - 2 defense
- The Dryad's Blessing grants an additional 8 defense.
- Riding a Mechanical Cart at full speed gives an additional 7 defense (expert mode only， but can be import to a normal world).
- Any sixth accessory that gives 4 defense at night, with a Warding prefix (expert mode only).
- The highest damage reduction is 73.6%.
- Armor-based reductions are multiplicative.
- Beetle Armor with shell - 45% reduction
- Accessory- and potion-based reductions are additive.
- Frozen Turtle Shell - 25% reduction
- Worm Scarf - 17% reduction
- Endurance Potion - 10% reduction
- Armor-based reductions are multiplicative.
(100%-45%) * (100%-(25%+17%+10%)) = 26.4% damage taken = 73.6% damage reduction
Template:Translation project