Defense

For defense mechanics, refer to Defense on the Terraria Wiki

Defense is a player statistic that determines how much damage can be taken per hit. The damage the player takes is reduced by 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

Source	Defense	Condition
Rover Drive	0 10	During the 20 second cooldown. When 10 second defense boost is active.
Aquatic Emblem	0 to 30	Gradually builds while submerged in liquid.
Aquatic Heart	1 5 10 15	Initially After defeating Skeletron In Hardmode After defeating Moon Lord
Aquatic Scourge (Lore)	1 -1	When Well Fed buff is active. When Well Fed buff is not active.
Baguette	2	When Well Fed buff is active.
Delicious Meat	2	When Well Fed buff is active.
Hadal Stew	2	When Well Fed buff is active.
Utensil Poker	2	When Well Fed buff is active.
Fungal Carapace	2	Always.
Polaris Parrotfish	2	When Polaris Boost buff is active.
Sea Shell	2 5	Initially. When submerged in liquid.
Shield of the Ocean	2 7	Initially. When submerged in liquid.
Deep Diver	2 +15%	Always. When submerged in liquid.
Corrupt Flask	3	While in the Corruption.
Crimson Flask	3	While in the Crimson.
Archaic Powder	3	While Underground or in the Underworld.
Craw Carapace	3	Always.
Ethereal Extorter	3 5 8	While in the Glowing Mushroom biome. While in the Snow biome. While in the Abyss.
Frost Barrier	4	Always.
Ambrosial Ampoule	4	Always.
Lunatic Cultist (Lore)	4	While the Lunar Events are active.
Crabulon (Lore)	5	When Mushy buff is active.
Crabulon	5	When Mushy buff is active.
Shroomerang	5	When Mushy buff is active.
Gladiator's Locket	5	Always.
Spirit Glyph	5	When Spirit Defense buff is active.
Living Dew	5	While in the Jungle.
Honey Dew	5	While in the Jungle.
Tequila	5	During the daytime when Tequila debuff is active.
Artemis Emblem	5	Always.
Elemental Quiver	5	Always.
The Desert Scourge (Lore)	5	While in the Desert or Sunken Sea.
Titan Scale Potion	5 30	When Titan Scale buff is active. 10 seconds after a true melee strike during the buff.
Yharim's Stimulants	5	When Yharim's Power buff is active.
Yharon's Kindle Staff	5	When Son of Yharon buff is active.
Godly Soul Artifact	5	When Son of Yharon buff is active.
Resilient Candle	5%	When Adamant Will buff is active.
Giant Shell	6	Always.
Cryo Stone	6	Always.
Regenator	6	Always.
Laudanum	6	Always.
The Absorber	6 11	Initially. When submerged in liquid.
Hallowed Rune	7	When Hallowed Defense buff is active.
Ornate Shield	8	Always.
Stress Pills	8	Always.
Giant Tortoise Shell	8	Always.
Frigid Bulwark	8	Always.
Asgard's Valor	8	Always.
Elysian Aegis	8 28	Initially. While Elysian Guard is active.
Heart of the Elements	9	Always.
Crown Jewel	10	While under the effects of a damaging debuff.
Asgardian Aegis	10 30	Initially. While Elysian Guard is active.
The Sponge	10 15	Initially. When submerged in liquid.
Frost Flare	10	When below 25% life.
Moonshine	10	When Moonshine debuff is active.
Crimson Effigy	10	When Crimson Effigy buff is active.
Skeletron (Lore)	10	While in the Dungeon.
Golem (Lore)	10	While standing still.
Moon Lord (Lore)	10	While gravity is flipped and the Gravity Globe is equipped.
Dark Sun Ring	10 40	During day. During night.
Rampart of Deities	12	Always.
Tequila Sunrise	15	During the daytime when Tequila Sunrise debuff is active.
Affliction	20	While equipped or when Afflicted buff is active
Draconic Elixir	16	When Draconic Surge buff is active.
Celestial Jewel	20	While under the effects of a damaging debuff.
Leviathan Ambergris	20	While submerged in water.
Astral Arcanum	20	While under the effects of a damaging debuff.
Ursa Sergeant	20	Always.
Draedon's Heart	25	While standing still.
Grax	30	When Grax Boost buff is active.
Permafrost's Concoction	30	When Encased buff is active.
Yharim's Gift	30	Always.
Fabled Tortoise Shell	35	Always.
The Amalgam	40	While submerged in liquid.
Grape Beer	-2	When Grape Beer debuff is active.
King Slime (Lore)	-3	Always.
Vodka	-4	When Vodka debuff is active.
Margarita	-6	When Margarita debuff is active.
White Wine	-6	When White Wine debuff is active.
Star Beam Rye	-6	When Star Beam Rye debuff is active.
Bloody Mary	-6	During a Blood Moon when Bloody Mary debuff is active.
Whiskey	-8	When Whiskey debuff is active.
Rum	-8	When Rum debuff is active.
Leviathan and Anahita (Lore)	-10	When not submerged in liquid.
Cryogen (Lore)	-10	Always.
The Twins (Lore)	-10	When above 50% life.
Caribbean Rum	-12	When Caribbean Rum debuff is active.
Cinnamon Roll	-12	When Cinnamon Roll debuff is active.
Fabsol's Vodka	-20	When Fab debuff is active.
Everclear	-40	When Everclear debuff is active.

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
Invisibility Potion	5	While Invisibility buff is active when holding a javelin.
Skeletron Prime (Lore)	5	Always.
Deific Amulet	10	Always.
Rampart of Deities	20	Always.
Omega Blue armor	50	Set bonus.
Reaper Tooth Necklace	100	Always.

Defense Reduction

Several weapons can permanently lower an enemy's defense on hit. Note that the enemy's defense will be reset if it gets changed by its AI.

Source	Defense Reduction
Corrupted Crusher Blade	5
Majestic Guard	10
Apoctolith	15
Deep Sea Dumbbell	15
Grand Guardian	15
Earth	50
Anti-materiel Rifle	50
Skullmasher	50
Grand Dad	Sets non-Boss enemy defense to 0

Vanilla changes

Defensive accessory modifiers now also increase damage reduction and gain more defense in Hardmode and Post-Moon Lord, with rarer defense modifiers granting a larger bonus.

• Hard provides 0.25% damage reduction; and increases 2 defense in Hardmode and 3 defense in Post-Moon Lord instead of 1.
• Guarding provides 0.5% damage reduction; and increases 3 defense in Hardmode and 4 defense in Post-Moon Lord instead of 2.
• Armored provides 0.75% damage reduction; and increases 4 defense in Hardmode and 6 defense in Post-Moon Lord instead of 3.
• Warding provides 1% damage reduction; and increases 6 defense in Hardmode and 8 defense in Post-Moon Lord instead of 4.

Several items had their defense values changed.

• A full set of Gladiator armor now provides 21 defense instead of 7.
• A full set of Obsidian armor now provides 19 defense instead of 16.
• The Hallowed Plate Mail now provides 18 defense instead of 15 and the Hallowed Greaves now provide 13 defense instead of 11.
• A full set of Solar Flare armor now provides 94 defense instead of 78.