Magic Resistance, or Magic Resist (MR) is a statistic that reduces incoming magic damage. All units have the magic resistance stat. Champions have base magic resistance that, by default, increases through growth by level.
Magic resistance can also be acquired by abilities, items, and runes. It stacks additively.
Formula
The formula to calculate post-mitigation magic damage based on raw magic damage received:
Due to the order of operations for penetration and reductions of either resistance, negative values almost never occur. For all non-negative resistance values this means using:
Solving the above formula for raw damage r gives
To determine how much damage will be dealt using raw and a given MR value we can use this formula:
Post Mitigation Damage = Raw Damage ÷ (1 + (Magic Resistance ÷ 100))
Examples using 1,000 raw damage
- 25 Magic Resistance → 1,000 ÷ (1 + 25 ÷ 100) = 1,000 ÷ 1.25 = 800
- Total damage reduction 20%, + 25% effective health, 1,000 post-mitigation damage = 1,250 Raw Damage
- 100 Magic Resistance → 1,000 ÷ (1 + 100 ÷ 100) = 1,000 ÷ 2 = 500
- Total damage reduction 50%, + 100% effective health, 1,000 post-mitigation damage = 2,000 Raw Damage
- 200 Magic Resistance → 1,000 ÷ (1 + 200 ÷ 100) = 1,000 ÷ 3 = 333.34
- Total damage reduction 66.66%, + 200% effective health, 1,000 post-mitigation damage = 3,000 Raw Damage
Stacking magic resistance
Following the above damage formula, each point of magic resist increases the effective health pool against magic damage by 1%, formally:
- Example: A unit with 60 magic resistance has 160% of its maximum health in its effective health, so if the unit has 1000 maximum health, it will take 1600 magic damage to kill it.
By definition, magic resist does not give diminishing returns of effective health. Each additional point of magic resist increases the effective health pool (against magic damage) by 1% of your maximum health. This is not changed by any amount of magic resist already held.
For a more detailed explanation, see this video.
Magic resistance as scaling
These use the champion's magic resistance to increase the magnitude of the ability. It could involve total or bonus magic resistance. By building magic resistance items, you can receive more benefit and power from these abilities.
Champions
Self
- and
- and
Enemy
Items
Self
Runes
Self
Neutral buffs
Self
Increasing magic resistance
Items
This table is automatically generated based on the data from Module:ItemData/data.
Item passives
- ( )
- ( )
Champion abilities
- , and
Runes
Neutral buffs
Ways to reduce magic resistance
- Main article: magic penetrationNote that magic penetration and magic resistance reduction are different.
List of champions' magic resistance
- Main article: List of champions' magic resistance
Most melee champions, along with 32 − 53.25 (based on level) or 32.1 − 53.35 (based on level).
, , and , have a base magic resistance of eitherMost ranged champions, shapeshifting champions who can become ranged in one of their forms ( , , , ), have base magic resistance of 30 − 38.5 (based on level).
, andThere are a few exceptions:
- 37 − 58.25 (based on level) with
- 32 − 40.5 (based on level) with
- 32 − 44.75 (based on level) with
- 28 − 49.25 (based on level) with
- 26 − 34.5 (based on level) with
- 28 − 49.25 (based on level) with
- 32 − 44.75 (based on level) with
- 28 − 49.25 (based on level) with
- 33.5 − 101.5 (based on level) with
- 32 − 44.75 (based on level) with
- 26 − 34.5 (based on level) with
- 28 − 49.25 (based on level) with
- 28 − 40.75 (based on level) with
- 36 − 44.5 (based on level) with
- 32 − 61.75 (based on level) with
- 39 − 60.25 (based on level) with
- 28 − 36.5 (based on level) with
- 28 − 49.25 (based on level) with
- 25 − 30.1 (based on level) with
Optimal efficiency (theoretical)
- Note: Effective burst health, commonly referred to just as 'effective health', describes the amount of raw burst damage a champion can receive before dying in such a short time span that he remains unaffected by any form of health restoration*. Unless champion's resists aren't reduced below zero, it will always be more than or equal to a champion's displayed health in their health bar and can be increased by buying items with extra health, armor and magic resistance. In this section, effective health will refer to the amount of raw 'magical damage' a champion can take.
In almost all circumstances, champions will have more maximum health than magic resistance, thus a single point of magic resistance will give more 'effective health' to a champion than a single point of health. However, if there is a case where max health is below the value of 'magic resistance + 100', the opposite becomes true.
Because of this relationship, theoretically, maximum effective health is attained by ensure that you have exactly 100 more max health than magic resistance, regardless of how much health or magic resistance you actually already have.
- Example: Given a theoretical situation where you start off with 1 health and 1 magic resistance and are given an arbitrary sufficient number of stat points (x ≥ 100), each of which you can use to increase either your health or magic resistance by 1 point, the way to maximize your effective health is to add points to your health until your health has 100 more points than magic resistance, then split the remaining stat points in half and share them between your health and magic resistance.
However, this is only theoretically true if we consider both health and magic resistance to be equally obtainable resources with simplified mechanism of skill point investment. In reality a player buys these stats for gold instead. So when attempting to ensure the balance of 'health = magic resistance + 100', consider it through gold value distributed to the stats. Because the gold value of 1 health is roughly 7 times smaller than 1 point of magic resistance (as of V8.7), distribution per point of health or magic resistance should be 12.5% gold into health and 87.5% gold into magic resistance once the 'health = magic resistance + 100' equilibrium is reached.
This model is highly simplified and cannot be exactly applied when buying any other item that aren't purely magic resistance or health oriented as they deviate the equilibrium. Going even further, the continuous model simplifies a discrete character of real shopping, as you cannot really buy 1.125 × 450, so you either opt to buy a single or a single , drastically unbalancing the equilibrium.
Broadly speaking, items which provide both health and magic resistance give a very high amount of effective health against magic damage compared to items which only provide health or only provide magic resistance. These items should be purchased when a player is seeking efficient ways to reduce the magic damage they take by a large amount. Furthermore, these items are among all available items the best ones to distribute their gold value equally among both health and magic resistance, thus working perfectly for rule of preserving equilibrium.
Conclusion
This information is strongly theoretical. Due to how there are many variables aside from health, magic resistance and gold value, "true equilibrium" is too complicated and unrealistic to achieve. However, a player can develop their intuition to itemize towards this equilibrium in a timely manner through the experience gained from the multitude of plays they perform.
The important thing to remember is that there is no reason to hold to the equilibrium too strictly, or else you might just lose the fun out of the game.
Trivia
- The old stat icon for
magic resistance was a blue recolor of the old stat icon for
armor, which seems to based on the old icon of .
- The game internally refers to magic resistance as spellBlock.
Last updated: July 29, 2020, patch V10.15
Without using 1464 magic resistance (which reduces magic damage by 93.607%).
or with which potentially allow for infinite amounts of magic resistance, the largest amount of magic resistance is reached with a level 18 at- Runes:
- (triggered with )
- 2 ×
Magic resistance rune shard
- Items:
- 1 ×
- 1 ×
- 4 ×
- Buffs:
- 4 ×
- Items = + + = 420 MR
- Runes =
8 × 2 = 185 MR
+ + + - MR Multiplier = 1 +
- 420 + 185) × 1.29 = 780.45 bonus MR MR = (
- 780.45 × 0.12 = 119.654 bonus MR bonus = 26 +
+ = 1.29
:
- Base MR = 53.35 MR
- Items = + + = 420 MR
- Runes =
8 × 2 = 185 MR
+ + + - Buffs = + + = 159.654 MR
- MR Multiplier = 1 +
- 53.35 + 420 + 185 + 159.654) × 1.79 = 1464.22716 MR MR = (
+ + = 1.79
:
- Prior to Patch 3.10, a level 18 with 1 , 5 , 3 points in
Resistance, 3 points in
Legendary Armor, , , , , an allied aura, a full page of Scaling Magic Resist runes, and active gave a total of approximately 1004 magic resistance. Switching for and having an enemy with the same setup use on and the allied use on the enemy , yielded a total of approximately 1297 magic resistance. This is the highest possible amount of magic resistance, which is 92.8% reduction.
- If disconnected from the fountain and had the same setup, he will have 2108 magic resistance. This is a 95.5% reduction.
- NOTE: This calculation does not include the
Defender mastery.