What is Magic Resist (MR) and how does it work in TFT?

Magic Resist is the magic-defense stat that reduces incoming magic damage. Each point of MR multiplies effective HP against magic damage by 1 + MR/100, so post-mitigation damage equals raw damage × 100/(100 + MR). That works out to 50 MR ≈ 33.3% magic damage reduced, 100 MR = 50% reduced — and the EHP curve scales linearly with no diminishing returns. MR does nothing against physical damage, and true damage ignores it entirely — including Burn, which deals percent-max-HP as true damage.

What's the difference between Magic Resist and Armor — and between Shred and Sunder?

Armor reduces incoming physical (AD) damage; Magic Resist reduces incoming magic (AP) damage. Both use the same reduction formula — R / (100 + R) — just applied to different damage types. The reduction debuffs mirror that split: Sunder reduces a target's Armor, Shred reduces a target's Magic Resist. Both are percent-based reductions, not flat. Duration varies by source — some applications are timed (a few seconds after a hit), others persist as auras while a condition holds.

When mixing flat and percent MR reduction, what is the order of operations?

Flat MR reduction is applied to the MR value first, then percent Shred operates on the remaining value, then the resistance formula runs against that final MR. Damage amplifiers — effects that read 'deals X% more damage' — apply post-mitigation in TFT, after the MR formula resolves. The practical consequence: stacking flat reduction first then percent Shred gets diminishing efficiency from the Shred (it operates on a smaller MR value), and resistances cannot go below 0 — flat reduction past zero is wasted.

Are there diminishing returns on stacking Magic Resist?

No — in effective-HP terms, every point of MR adds a fixed slice of EHP regardless of how much MR you already have. The formula EHP = HP × (1 + MR/100) means going from 0 to 100 MR doubles your effective HP versus magic damage (1.0× → 2.0×), and another +100 MR adds the same fixed slice on top (2.0× → 3.0×). The percentage-reduction curve flattens, but EHP scales linearly. What stacking only MR leaves you exposed to is physical damage (which Armor handles) and true damage, which ignores both resists. Layer MR with Armor and HP.

How do Shred and other Magic Resist reduction effects stack with each other?

The Shred keyword does not stack. When multiple Shred sources hit the same target, they don't add together — Riot's exact patch-note phrasing is 'this effect does not stack'. Two 30% Shreds don't combine into 60%; only one Shred is active at a time. Note that a few champion abilities and items apply flat MR reduction (a small fixed value, e.g., −X MR per hit) — those follow different stacking rules than the percent Shred keyword, even when their tooltip text also reads 'Shred'.

Can a unit's Magic Resist go below zero, and does that amplify damage taken?

No — not in current TFT. Resistances are floored at 0. Once Shred and other MR-reduction effects bring a unit to 0 MR, any further reduction is wasted: incoming magic damage is fully unmitigated (essentially true damage), but it isn't amplified. The reduction multiplier 100 / (100 + MR) tops out at 1.0×. TFT diverged from base League around Set 9 (patch 13.16, August 2023), when Riot patched champions like Samira and Lux so their reductions could no longer push resistances below 0; the system has stayed floored at 0 across every set since.

Does Magic Resist help against true damage or Burn ticks?

No. Magic Resist only reduces incoming magic damage, so true damage of any kind passes through it untouched. Burn is a clear example — its damage-over-time tick is dealt as true damage based on a percentage of the target's maximum Health, so neither MR nor Armor mitigates it. MR also doesn't reduce physical damage. Because MR is purely a damage-reduction stat, a unit with stacked MR but a thin Health pool can still be melted by any source tagged true damage in its tooltip.

Does TFT have Magic Penetration like League of Legends?

No — TFT does not expose a 'Magic Penetration' stat the way League does. There is no item, trait, or buff that grants flat or percent magic penetration as a holder-side stat. Instead, TFT reduces a target's effective Magic Resist through Shred, a debuff applied to the target (most commonly via on-hit item effects, certain trait actives, and ability scripts). Damage amplifiers — clauses that increase outgoing damage by a percent — are a separate mechanic and don't reduce MR; they stack alongside Shred rather than replacing it.

Magic Resist

The magic-defense stat that reduces incoming AP damage. Many sustain items, the Bastion frontline trait, and "Gain X Armor and Magic Resist" effects grant or scale off it; Shred is its inverse.

Listed in: Buffs

Items (56)

Refine list…

Adaptive Helm
- +20 MR
- +3 Mana Regen
Gain an additional 15% Mana from all sources. The holder gains an additional bonus based on their Role: Tanks and Fighters: Gain 30 Armor and Magic Resistance. Other Roles: Gain 10% Attack Damage and Ability Power.
Bloodthirster
- +20 MR
- +15% AD
- +15 AP
- +20% Omnivamp
Once per combat at 40% Health, gain a 25% max Health Shield that lasts up to 5 seconds.
Dragon's Claw
- +60 MR
Gain 6% max health. Every 2 seconds, heal 2.5% max Health.
Evenshroud
- +250 HP
- +20 MR
30% Sunder enemies within 2 hexes. Gain 15 Armor and Magic Resist for the first 15 seconds of combat. Sunder: Reduce Armor
Gargoyle Stoneplate
- +100 HP
- +25 Armor
- +25 MR
Gain 10 Armor and 10 Magic Resist for each enemy targeting the holder.
Ionic Spark
- +250 HP
- +35 MR
- +15 AP
30% Shred enemies within 2 hexes. When enemies cast an Ability, deal magic damage equal to 150% of the Mana spent Shred: Reduce Magic Resist
Kraken's Fury
- +20 MR
- +10% AD
- +10% AS
Attacks grant 3.5% stacking Attack Damage, up to 15 attacks. After 15 attacks, gain 15% Attack Speed.
Protector's Vow
- +25 Armor
- +25 MR
- +1 Mana Regen
Combat Start: Gain 20 Mana. At 40% Health, gain 15 Mana and a Shield equal to 20% max Health.
Quicksilver
- +20 MR
- +15% AS
- +20% Crit
Combat Start: Gain immunity to crowd control for 18 seconds. Gain 3% stacking Attack Speed every second.
Void Staff
- +15% AS
- +35 AP
- +1 Mana Regen
Damage from attacks and Abilities 30% Shred the target for 5 seconds. This effect does not stack. Shred: Reduce Magic Resist
Negatron Cloak
- +20 MR
Radiant Adaptive Helm
- +40 MR
- +7 Mana Regen
Gain an additional 30% Mana from all sources. The wearer gains an additional bonus based on their Role: Tank/Fighter: Gain 80 Armor and Magic Resistance. Marksman/Caster: Gain 40% Attack Damage and Ability Power.
Radiant Bloodthirster
- +40 MR
- +30% AD
- +30 AP
- +40% Omnivamp
Once per combat: At 40% Health, gain a 50% max Health Shield that lasts up to 5 seconds.
Radiant Dragon's Claw
- +120 MR
Gain 28% max health. Every 2 seconds, heal 5% max Health.
Radiant Evenshroud
- +500 HP
- +40 MR
30% Sunder enemies within 3 hexes. Gain 50 Armor and Magic Resist for the first 20 seconds of combat. Sunder: Reduce Armor
Radiant Gargoyle Stoneplate
- +300 HP
- +50 Armor
- +50 MR
Gain 20 Armor and 20 Magic Resist for each enemy targeting the holder.
Radiant Ionic Spark
- +500 HP
- +70 MR
- +30 AP
30% Shred enemies within 2 hexes. When enemies cast an Ability, deal magic damage equal to 300% of the Mana spent. [Direct damage item] Shred: Reduce Magic Resist
Radiant Kraken's Fury
- +40 MR
- +20% AD
- +20% AS
Attacks grant 7% stacking Attack Damage, up to 15 attacks. After 15 attacks, gain 30% Attack Speed.
Radiant Protector's Vow
- +50 Armor
- +50 MR
- +2 Mana Regen
Combat Start: Gain 40 Mana. At 40% Health, gain 30 Mana and a Shield equal to 50% max Health.
Radiant Quicksilver
- +40 MR
- +40% AS
- +40% Crit
Combat Start: Gain immunity to crowd control for 45 seconds. Gain 6% stacking Attack Speed every second.
Radiant Void Staff
- +30% AS
- +75 AP
- +2 Mana Regen
Damage from attacks and Abilities 30% Shred the target for the rest of combat. This effect does not stack. Shred: Reduce Magic Resist
Aegis of Dusk
- +400 HP
- +70 MR
Every 2.5 seconds, steal 3 Magic Resist from enemies within 1 hex and deal 15%–50% (by Stage) of the holder's Magic Resist as magic damage. If Aegis of Dawn is also equipped, trigger this item's effect every 1.25 seconds instead. Damage increases based on Stage.
Blighting Jewel
- +60 AP
- +2 Mana Regen
Dealing magic damage reduces the target's Magic Resist by 6. If their Magic Resist is 0, grant the holder 2 Mana instead. Ability damage can only trigger on each enemy once every 0.5 seconds.
Forbidden Idol
- +200 HP
- +25 Armor
- +25 MR
Shields have 50% of their value converted to max Health instead.
Hullcrusher
- +60 Armor
- +60 MR
Combat Start: If there are no adjacent allies, gain 400 Health, 10% Attack Damage, and 10% Ability Power.
Infinity Force
- +300 HP
- +30 Armor
- +30 MR
- +30% AD
- +30% AS
- +30 AP
Tons of EVERYTHING!
Lesser Mirrored Persona
- +100 HP
- +10 Armor
- +10 MR
- +10% AD
- +10% AS
- +10 AP
Share 15% of the holder's bonus Attack Damage, Ability Power, Attack Speed, Armor, Magic Resist, and Health with other Mirrored Persona holders. Can't be Reforged Unique: one per champion
Lightshield Crest
- +55 Armor
- +55 MR
Every 3 seconds, Shields the lowest percent Health ally for 70% of the holder's combined Armor and Magic Resist for 5 seconds. On death grants this shield to all allies.
Locket of the Iron Solari
- +150 HP
Combat start: The holder and allies within 2 hexes in the same row gain a 250 Shield, 20 Armor, and 20 Magic Resist for 20 seconds. [Support item]
Mirrored Persona
- +100 HP
- +10 Armor
- +10 MR
- +10% AD
- +10% AS
- +10 AP
Every 6 player combats gain a lesser copy of Mirrored Persona ( /6). Share 15% of the holder's bonus Attack Damage, Ability Power, Attack Speed, Armor, Magic Resist, and Health with other Mirrored Persona holders. Can't be Reforged, Lesser copies do not produce copies. Unique: one per champion
Mogul's Mail
- +300 HP
Grants 1 Armor, 1 Magic Resist, and 5 Health when taking damage, stacking up to 35 times. At full stacks, grant 1 gold and continue gaining 1 gold every 11 seconds. [Unique - only 1 per champion]
Seeker's Armguard
- +10 Armor
- +10 MR
- +25 AP
- +20% Omnivamp
Takedowns increase the holder's Armor, Magic Resist, and Ability Power by 20.
Shadow Puppet
- +10 Armor
- +10 MR
- +10% AS
Spawn a clone that copies the holder's items. The clone has 60% max Health and deals 40% damage. [Unique - only 1 per champion]
Silvermere Dawn
- +80 Armor
- +80 MR
- +140% AD
Grants immunity to Stuns and the holder's attacks Stun the target for 0.8 seconds. The holder's Attack Speed is locked at 0.5.
The Indomitable
- +500 HP
- +20 Armor
- +20 MR
The holder's Move Speed is drastically reduced. Gain 15% max Health, stun immunity, and pull the current target into melee range.
Thresh's Lantern
- +400 HP
- +35 Armor
- +35 MR
After 6 seconds of combat, pull the leftmost benched unit onto the battlefield. While that unit lives, 20% of all damage the holder would take is redirected to them. Traits of champions flung onto the board do not become active
Trickster's Glass
- +10 Armor
- +10 MR
- +10% AS
- +15% Crit
Summon a clone with 70% base Health and +10% max Mana. You cannot equip items to the clone. The clone benefits from active traits [Unique - only 1 per champion]
Wit's End
- +400 HP
- +20 Armor
- +20 MR
- +25% AS
Attacks deal 30–100 (by Stage) bonus magic damage. Heals the holder for 30% of all magic damage dealt. Damage increases based on Stage.
Zhonya's Paradox
- +25 Armor
- +25 MR
- +25 AP
Once per combat at 40% Health, become invulnerable and untargetable for 3 seconds. [Unique - only 1 per champion]
Arbiter Emblem
- +20 Armor
- +20 MR
- +30% AS
The holder gains the Arbiter trait.
```
Scribe a unique divine law, allowing you to choose an effect to apply to Arbiters when a chosen cause occurs.
```
2
Choose a cause and effect for your law
3
Effects are stronger.
Bastion Emblem
- +30 Armor
- +30 MR
The holder gains the Bastion trait. After the first 10 seconds of combat, the holder gains 70% Attack Speed.
```
Your team gains 15 Armor and Magic Resist.

Bastions gain more, and the value doubles in the first 10 seconds of combat.
```
2
16
4
40
6
60
Meeple Emblem
- +20 Armor
- +20 MR
- +2 Mana Regen
The holder gains the Meeple trait and 4% Damage Amp and 50 Health per.
```
Meeple attract Meeps that empower Meeple abilities in meepy ways. They also gain bonus Health.

Cloning time = Champion cost
```
3
2, 100
5
3, 350
7
4, 450
10
6, 550
N.O.V.A. Emblem
- +200 HP
- +20% Crit
The holder gains the N.O.V.A. trait. N.O.V.A. Strike: Gain 25% Attack Speed and 10 Armor and Magic Resist. Other allies gain 10% Attack Speed and 10 Armor and Magic Resist.
```
Aatrox: Ally Damage 30% Shred and Sunders enemies
Caitlyn: Grant allies 20% Attack Speed
Akali: Allies gain Precision
Maokai: Allies heal 12% max Health
Kindred: Shield the strongest Tank for 800
Emblem: Allies deal 10% stacking bonus true damage
```
2
6 seconds into combat, N.O.V.A. grant a power surge to allies based on champions.
5
Gain a Striker selector. The chosen N.O.V.A. activates their Strike during the power surge.
Vanguard Emblem
- +20 Armor
- +20 MR
The holder gains the Vanguard trait. Gain 2% Ability Power whenever an ally gains a shield.
```
Vanguards gain 5% Durability while Shielded. 

Combat start and 50% Health: Gain a max Health Shield for 10 seconds.
```
2
16% max Health
4
30% max Health
6
40% max Health
Voyager Emblem
- +20% AD
- +20 AP
The holder gains the Voyager trait. Combat Start: The holder and allies within 1 hex in the same row gain a bonus based on the holder's role. - Tanks: 10 Armor and Magic Resist - Fighters/Assassins: 10% Omnivamp - Other Roles: 10% Attack Speed
```
Combat Start: Your Tanks gain a Shield for 15 seconds. Your other allies gain Damage Amp. 

Voyagers gain double.
```
2
175 Shield; 9%
3
250 Shield; 15%
4
350 Shield; 18%
5
500 Shield; 22%
6
700 Shield; 27%
Cyclonic Slicers
- +15 Armor
- +15 MR
- +20% AD
- +20 AP
Gain 3 orbiting razors. Razors deal ? magic damage, and 30% Shred and Sunder enemies for 4 seconds. Deal 10% increased damage to Shredded or Sundered enemies. Damage increases based on Stage. Recommended Roles: Attack or Magic Fighter
Deep Freeze
- +550 HP
- +30 Armor
- +30 MR
The first time you fall below 90%, 60%, 40%, and 20% health, gain a 20% max health shield for 4 seconds. When this happens, release a frost nova that stuns enemies within 2 hexes for 2 seconds and deals magic damage equal to 15% of their max Health. The radius increases by 1 each nova. Recommended Roles: Attack or Magic Tank
Iceblast Armor
- +250 HP
- +30 Armor
- +30 MR
The first time you fall below 70% and 35% health, gain a 25% max health shield for 4 seconds and release a frost nova that stuns enemies within 3 hexes for 2 seconds. Recommended Roles: Attack or Magic Tank
Leonine Lamentation
- +400 HP
- +40 Armor
- +40 MR
Every 15% max health lost, fire crescent projectiles in 3 lines dealing physical damage equal to 50% of the holder's Armor and Magic Resist. Steal 10 Armor and Magic Resist from all enemies hit. Recommended Roles: Attack or Magic Tank
Lioness's Lament
- +200 HP
- +30 Armor
- +30 MR
Every 15% max health lost, fire crescent projectiles in a line dealing physical damage equal to 50% of the holder's Armor and Magic Resist. Steal 4 Armor and Magic Resist from all enemies hit. Recommended Roles: Attack or Magic Tank
Omniweapon
- +10000 HP
- +100 Armor
- +100 MR
- +100% AD
- +100% AS
- +100 AP
- +75% Crit
- +100% Omnivamp
- +10 Mana Regen
The pinnacle of Anima technology.
Unceasing Cyclone
- +40 Armor
- +40 MR
- +30% AD
- +30 AP
Gain 6 orbiting razors. Razors deal ? true damage, and 30% Shred and Sunder enemies for the rest of combat. Deal 30% increased damage to Shredded or Sundered enemies. Damage increases based on Stage. Recommended Roles: Attack or Magic Fighter
Heavy Plating

Gain 300 Base Health, 20 Armor, and 20 Magic Resistance.
Reactive Armor

Taking damage from enemies grants 4 bonus Armor and Magic Resistances, up to 50.
Ripper Bullets

Attacks reduce enemy Armor and Magic Resistance by 1.
Ripper Bullets+

Attacks reduce enemy Armor and Magic Resistance by 2.

Augments (10)

Refine list…

Bronze For Life II Prismatic

Your team gains 2% Damage Amp and 4 Armor and Magic Resist for each Bronze-tier trait.

Bodyguard Training Gold

Allies gain 15 Armor and Magic Resist, increased by 2 per player level.

Gizmos & Gadgets Championship, 2022

Climb The Ladder II Gold

Each time an ally dies, allies that share at least one trait with them gain 7% Ability Power, 7% Attack Damage, 6 Armor, and 6 Magic Resist.

Group Hug II Gold

Combat start: Allies grant other adjacent allies 9 Armor and Magic Resist. This effect stacks.

Plot Armor Gold

Your team gains 8 Armor and Magic Resist. After falling below 50% Health, increase this to 40 for the rest of combat.

Climb The Ladder I Silver

Each time an ally dies, allies that share at least one trait with them gain 3.5% Ability Power, 3.5% Attack Damage, 3.5 Armor, and 3.5 Magic Resist.

Corrosion Silver

Enemies in the first two rows lose 4 Armor and Magic Resist every 2 seconds.

Group Hug I Silver

Combat start: Allies grant other adjacent allies 6 Armor and Magic Resist. This effect stacks.

Lineup Silver

Your team gains 2 Armor and Magic Resist for each ally that starts combat in the front two rows.

Twin Guardians Silver

If you have exactly 2 allies in your first row, grant them 100 bonus Health, 35 Armor, and 35 Magic Resist.

Champions (5)

1 Leona

Magic Tank

Shield of Daybreak
Gain   Shield for 4 seconds. Bash the current target, dealing 100 / 150 / 225  magic damage and stunning them for 1.75 / 1.75 / 2 seconds.

1 Poppy

Magic Tank

Huddle Up!
Gain 400 / 475 / 575  Shield for 4 seconds. For the duration, allies within two hexes gain 15 / 25 / 60  Armor and Magic Resistance.

Meep Bonus: Meeps grant 125 / 160 / 210  Shield to the nearest ? allies for 4 seconds.

2 Jax

Magic Tank

Counter Star-ike
Enter a defensive stance for 3 seconds, reducing incoming damage by 20 / 25 / 30 and gaining 400 / 450 / 500  Shield. When the stance ends, strike all nearby enemies, dealing   magic damage and Stunning them for 1 / 1.25 / 1.5 second(s).

4 Aurelion Sol

Magic Caster

Deathbeam
Channel a deathbeam in a line towards the current target for 3 seconds. It deals   magic damage per second, reduced by 80% per enemy it passes through. Deathbeam ignores 30% of the enemy's Magic Resist.

4 The Mighty Mech

Attack Tank

Gravity Matrix
Enter a defensive stance for 4 seconds gaining 20 / 20 / 60% Durability. While in the defensive stance, attract nearby enemy projectiles and heal 900 / 1300 / 3000  over the duration. When this ends, release a shockwave that deals   as physical damage in a 2-hex range.

Traits (4)

Refine list…

Bastion

Your team gains 15 Armor and Magic Resist.

Bastions gain more, and the value doubles in the first 10 seconds of combat.

Eradicator

Enemies have 10% less Armor and Magic Resist.

Redeemer

Stargazer

Stargazers chart a different constellation every game. This game: The Mountain

Every 5 player combats, gain a Stargazer Emblem. Stargazers in empowered hexes gain various bonuses.

More hexes reveal at each player level

Frequently asked questions

What is Magic Resist (MR) and how does it work in TFT?
Magic Resist is the magic-defense stat that reduces incoming magic damage. Each point of MR multiplies effective HP against magic damage by 1 + MR/100, so post-mitigation damage equals raw damage × 100/(100 + MR). That works out to 50 MR ≈ 33.3% magic damage reduced, 100 MR = 50% reduced — and the EHP curve scales linearly with no diminishing returns. MR does nothing against physical damage, and true damage ignores it entirely — including Burn, which deals percent-max-HP as true damage.
Sources
What's the difference between Magic Resist and Armor — and between Shred and Sunder?
Armor reduces incoming physical (AD) damage; Magic Resist reduces incoming magic (AP) damage. Both use the same reduction formula — R / (100 + R) — just applied to different damage types. The reduction debuffs mirror that split: Sunder reduces a target's Armor, Shred reduces a target's Magic Resist. Both are percent-based reductions, not flat. Duration varies by source — some applications are timed (a few seconds after a hit), others persist as auras while a condition holds.
Sources
- Resistances (TFT) — League of Legends Wiki (opens in new tab)
- How Armor and Magic Resistance works in TFT — LeDuck (Tacter) (opens in new tab)
When mixing flat and percent MR reduction, what is the order of operations?
Flat MR reduction is applied to the MR value first, then percent Shred operates on the remaining value, then the resistance formula runs against that final MR. Damage amplifiers — effects that read 'deals X% more damage' — apply post-mitigation in TFT, after the MR formula resolves. The practical consequence: stacking flat reduction first then percent Shred gets diminishing efficiency from the Shred (it operates on a smaller MR value), and resistances cannot go below 0 — flat reduction past zero is wasted.
Sources
Are there diminishing returns on stacking Magic Resist?
No — in effective-HP terms, every point of MR adds a fixed slice of EHP regardless of how much MR you already have. The formula EHP = HP × (1 + MR/100) means going from 0 to 100 MR doubles your effective HP versus magic damage (1.0× → 2.0×), and another +100 MR adds the same fixed slice on top (2.0× → 3.0×). The percentage-reduction curve flattens, but EHP scales linearly. What stacking only MR leaves you exposed to is physical damage (which Armor handles) and true damage, which ignores both resists. Layer MR with Armor and HP.
Sources
- How Armor and MR work in League — Boosteria ("scales linearly with resistance") (opens in new tab)
- How Armor and Magic Resistance works in TFT — LeDuck (Tacter) (opens in new tab)
How do Shred and other Magic Resist reduction effects stack with each other?
The Shred keyword does not stack. When multiple Shred sources hit the same target, they don't add together — Riot's exact patch-note phrasing is 'this effect does not stack'. Two 30% Shreds don't combine into 60%; only one Shred is active at a time. Note that a few champion abilities and items apply flat MR reduction (a small fixed value, e.g., −X MR per hit) — those follow different stacking rules than the percent Shred keyword, even when their tooltip text also reads 'Shred'.
Sources
Can a unit's Magic Resist go below zero, and does that amplify damage taken?
No — not in current TFT. Resistances are floored at 0. Once Shred and other MR-reduction effects bring a unit to 0 MR, any further reduction is wasted: incoming magic damage is fully unmitigated (essentially true damage), but it isn't amplified. The reduction multiplier 100 / (100 + MR) tops out at 1.0×. TFT diverged from base League around Set 9 (patch 13.16, August 2023), when Riot patched champions like Samira and Lux so their reductions could no longer push resistances below 0; the system has stayed floored at 0 across every set since.
Sources
Does Magic Resist help against true damage or Burn ticks?
No. Magic Resist only reduces incoming magic damage, so true damage of any kind passes through it untouched. Burn is a clear example — its damage-over-time tick is dealt as true damage based on a percentage of the target's maximum Health, so neither MR nor Armor mitigates it. MR also doesn't reduce physical damage. Because MR is purely a damage-reduction stat, a unit with stacked MR but a thin Health pool can still be melted by any source tagged true damage in its tooltip.
Sources
Does TFT have Magic Penetration like League of Legends?
No — TFT does not expose a 'Magic Penetration' stat the way League does. There is no item, trait, or buff that grants flat or percent magic penetration as a holder-side stat. Instead, TFT reduces a target's effective Magic Resist through Shred, a debuff applied to the target (most commonly via on-hit item effects, certain trait actives, and ability scripts). Damage amplifiers — clauses that increase outgoing damage by a percent — are a separate mechanic and don't reduce MR; they stack alongside Shred rather than replacing it.
Sources

Description

Items (56) #

Augments (10) #

Champions (5) #

Traits (4) #

Frequently asked questions

Items (56)

Augments (10)

Champions (5)

Traits (4)