Damage Reduction

- Main article: Combat

Damage Reduction is a stat that does exactly what it suggests: It reduces the amount of damage taken by a player or monster. Unlike other combat numbers that are complex calculations, a player's Damage Reduction is determined by simply adding together all Damage Reduction bonuses the player has, whether from equipment or something else like a Damage Reduction Potion or Leonardo.

Many monsters have Damage Reduction modifiers that affect their defensive stats.

Mechanics

Whenever a player or monster with Damage Reduction greater than 0% would receive damage, instead the damage they take is equal to:

[math]\displaystyle{ \text{Damage Taken} = \text{Base Damage} \times \left (1 - \text{Damage Reduction} \right ) }[/math]

Note that the Combat Triangle will affect how much damage reduction the player has if they are using a different style from the monster.

Damage Reduction Modifiers

Source	Type	Damage Reduction	Other Modifiers
Damage Reduction Potion IV	Item	+10% Damage Reduction
Damage Reduction Potion III	Item	+6% Damage Reduction
Guardian Amulet	Item (Amulet, Passive)	+5% Damage Reduction	+10% Attack Interval
Holy Aegis	Prayer	+5% Damage Reduction
Damage Reduction Potion II	Item	+4% Damage Reduction
Stone Skin	Prayer	+3% Damage Reduction
Damage Reduction Potion I	Item	+2% Damage Reduction
Lake Swim	Agility Obstacle 6	+1% Damage Reduction	+3% Chance To Preserve Prayer Points +5% Damage To All Monsters
Raft Building	Agility Obstacle 8	+1% Damage Reduction	+2% Damage To All Monsters +20 Maximum Hitpoints
Frozen Maze	Agility Obstacle 11	+1% Damage Reduction	-20% Ammo Preservation -0.1s Monster Respawn Timer -20% Rune Preservation -3 Prayer Point Cost for Prayers (Prayer Point cost cannot go below 1)
Smithing Lesser Relic	Item (Consumable)	+1% Damage Reduction	-5% Smithing Interval +10% Global Evasion
Yak	Item (Summon1, Summon2)	+1% Damage Reduction
Erran	Pet	+1% Damage Reduction
Leonardo	Pet	+1% Damage Reduction
Safeguard	Prayer	+1% Damage Reduction
Martyr	Prayer	-1% Damage Reduction	+40% Reflect Damage
Spike Trap	Agility Obstacle 7	-2% Damage Reduction	-40 Maximum Hitpoints
Knight's Summoning Defender	Item (Shield, Passive)	-3% Damage Reduction	-0.1s Attack Interval -10% Summoning Familiar Attack Interval
Mud Dive	Agility Obstacle 4	-4% Damage Reduction	+20 Maximum Hitpoints +5% Melee Accuracy Rating +2% Melee Maximum Hit
Masquerade Mask	Item (Consumable)	-4% Damage Reduction	-25% Thieving Stun Interval +45 Stealth while Thieving
Lava Jump	Agility Obstacle 9	-6% Damage Reduction	-6% Auto Eat Efficiency -6% Global Mastery XP -0.3s Monster Respawn Timer
Merman Pendant	Item (Amulet, Passive)	-10% Damage Reduction	-20% Attack Interval All player special attacks are disabled +75% Accuracy Rating +50% Maximum Hit