Thornmail

Thornmail is a Legendary Tank item costing 2450 gold providing +75 Armor and +150 Health. Its passive THORNS retaliates every time the carrier is struck by a basic attack on-hit: dealing 20 + 10% bonus armor magic damage back to the attacker. If the attacker is a champion, they additionally receive Grievous Wounds for 3 seconds. THORNS is reactive damage — it does NOT trigger spell effects. It is not blocked by spell shields, not a projectile, and crucially triggers regardless of whether the basic attack deals damage — including when the carrier uses a shield or is invulnerable. THORNS will NOT trigger on dodged, blocked, or missed attacks (including when the attacker is blinded). The minimum reflect damage is 27.5 magic damage at purchase (20 base + 10% of 75 bonus armor). Grievous Wounds applies to the attacker even if they are shielded or invulnerable at the moment of the attack. Critically, healing effects triggered by the attacking basic attack (life steal, Xin Zhao’s Determination) are reduced by Grievous Wounds on the same attack that triggers THORNS — GW is applied on the triggering auto, not after it. Thornmail is the dedicated anti-healing armor item, and the primary Grievous Wounds source for physical-damage-focused tank builds. Limited to 1 Thornmail per player.

Thornmail is a Legendary-tier item available on Summoner’s Rift (5v5), ARAM, Nexus Blitz, and Arena. Categorized under Tank, Health & Regeneration, and Armor menus. Keywords: grievous wounds. ID 3075. Limited to 1 Thornmail per player. Sell value: 1715 gold.

📊 Stats at a Glance

💡 The Bonus Armor Scaling — Why Stacking Armor Increases THORNS Damage: THORNS deals 20 + 10% of bonus armor as magic damage per reflect. Bonus armor includes armor from all items and runes — not the champion’s base armor from level scaling. Thornmail’s own +75 armor contributes 7.5 to THORNS damage at purchase. Adding Sunfire Aegis (+35 armor) increases THORNS to 20 + 10.5 = 30.5. Adding Frozen Heart (+70 armor) brings total bonus armor to 220, making THORNS 20 + 22 = 42 magic damage per basic attack reflect. Deep armor stacking is therefore doubly efficient on Thornmail — armor reduces incoming physical damage AND increases THORNS’s outgoing reflect per hit. The bonus armor scaling is not substantial as a primary damage source, but it ensures Thornmail retains relevance as the build deepens into armor.

💡 Grievous Wounds on the Triggering Attack — Not the Next One: One of Thornmail’s most tactically important properties: when a basic attack triggers THORNS, GW is applied to the attacker and immediately reduces the healing from that very same attack. Healing effects triggered by a basic attack — life steal, Xin Zhao’s Determination heal, any on-hit healing — are first reduced by the GW before the heal resolves. This means the first auto against a Thornmail carrier already heals 40% less than normal, not just the second onward. Against Draven at 20% life steal landing a 300 physical damage auto: the life steal would normally heal 60 HP — with THORNS GW applied on the same hit, it heals 36 HP (60 × 60% = 36 HP after 40% GW reduction). There is no free first auto before GW takes effect on healing sources that trigger on the basic attack itself.

🔨 Recipe & Build Path

💡 Bramble Vest as First-Back GW Source: Bramble Vest (800g) provides an early THORNS-like passive with armor — it is the component form of Thornmail and carries a weaker version of THORNS. Against heavy-healing lanes (Nasus with Lifesteal, Soraka support, Yasuo with Bloodline rune), buying Bramble Vest at 800g on first back establishes Grievous Wounds immediately, before the full Thornmail can be completed. The 800g is fully absorbed into Thornmail’s final cost with no gold waste — Bramble Vest is a cost-efficient GW timing tool that transitions directly into the completed item.

⚡ Passive — UNIQUE: THORNS

EFFECT: When struck by a basic attack on-hit, deal 20 + 10% bonus armor magic damage to the attacker. If the attacker is a champion, inflict them with Grievous Wounds for 3 seconds. THORNS is reactive damage that does not trigger spell effects, is not blocked by spell shields, is not a projectile, and fires even when the carrier takes zero damage from the attack (shield or invulnerability). GW applies to the attacker even if they are shielded or invulnerable. Healing effects from the triggering attack are immediately reduced by GW before they resolve. THORNS does NOT trigger on dodged, blocked, or blind-missed attacks.

⚠️ THORNS Fires During Carrier’s Own Invulnerability: THORNS triggers regardless of whether the basic attack deals damage to the carrier. This includes when the carrier is using a shield (Sterak’s Gage Lifeline, Locket of the Iron Solari active) or is invulnerable (Kayle R, Taric R, Sion Glory in Death). An enemy who continues auto-attacking a Kayle-ulted ally with Thornmail is continuously receiving THORNS magic damage and refreshing GW during the invulnerability window, even though their attacks are dealing zero damage. This interaction makes Thornmail’s passive particularly punishing for auto-attack-dependent champions who commit to targets during defensive cooldowns.

⚠️ Dodge, Block, and Blind Are the Three THORNS Non-Triggers: THORNS has three explicit non-trigger conditions that are mechanically distinct from invulnerability. Dodge (Jax Counter Strike E): the attack is registered as dodged, THORNS does not fire. Block (Pantheon passive, similar effects): the attack is blocked, THORNS does not fire. Blind miss (Teemo Q Blinding Dart, blind effects): the attacker misses due to blind status, THORNS does not fire. These three conditions are the only reliable ways to auto-attack a Thornmail carrier without triggering the reflect — understanding them determines whether building blind sources or dodge has counterplay value against a Thornmail tank.

🎯 Who Should Buy This Item

Champion Archetypes

• Armor Tanks Facing Heavy-Healing Physical DPS Compositions: Thornmail is specifically designed for physical damage + healing combinations — the armor addresses the physical damage, THORNS GW addresses the healing. Against a team composition of Draven ADC + Soraka support + Conqueror Nasus top, every physical threat on the team both builds armor and applies GW from THORNS automatically. The passive fires without any active input — any basic attack against a Thornmail carrier triggers GW without the Thornmail carrier needing to cast any ability or press any button.
• Tanks Who Need GW Without Spending an Active: Thornmail is one of the few items in the game that applies Grievous Wounds passively on the attacker’s basic attacks — no active ability, no targeted spell, no additional input. Against champions who rely on basic attack healing (Aatrox Q chains, Fiora Grand Challenge, Draven with massive life steal) the GW fires automatically every time they auto the Thornmail carrier. For tanks who have no GW ability in their kit and fight auto-attack-heavy opponents, Thornmail is the most gold-efficient GW application available.
• Top Lane and Support Tanks in Attack-Speed-Dependent Metas: THORNS fires once per incoming basic attack. Against attack-speed-stacking ADCs (Jinx Fishbones + lethal tempo, Twitch with full attack speed), the number of THORNS procs per second is the carrier’s damage output — a 2.5 attack-speed Jinx triggers THORNS 2.5 times per second, dealing 2.5 × 27.5 = 68.75 magic damage per second passively back to Jinx. THORNS DPS scales linearly with the attacker’s attack speed — fast auto-attacking carries deal more THORNS damage to themselves per second than slow-attacking targets.

Specific Champion Examples

Rammus THORNS Amplification — Special Case

Rammus Defensive Ball Curl (W) is the single champion ability that most dramatically amplifies THORNS. During Defensive Ball Curl, Rammus gains a substantial amount of bonus armor — at rank 5 W, approximately +200 additional bonus armor temporarily. THORNS during W calculates as: 20 + 10% × (normal bonus armor + W bonus armor). At 75 base Thornmail armor + 100 additional armor items + 200 W armor = 375 total bonus armor: THORNS fires for 20 + 37.5 = 57.5 magic damage per hit while W is active. An ADC who continues attacking Rammus during W receives 57+ magic damage per hit — against a 1.5 AS Tristana that is 86 magic DPS from THORNS alone during W, plus Rammus’s W’s own reflect damage from its independent passive. The two passives stack — THORNS and Rammus W’s Spiked Shell are different damage sources that both fire simultaneously.

⏰ When to Buy

The Decision Rule — Two Conditions

Thornmail is correct when both of the following are true simultaneously: (1) the primary damage threat is physical damage from basic attacks, and (2) that threat heals significantly through life steal, omnivamp, or on-hit healing. If only one condition is met — physical damage without healing, or healing without physical damage — a different item is more appropriate. Against a physical ADC who builds no sustain items (Draven, Caitlyn without life steal): armor without GW is sufficient (Sunfire, Frozen Heart). Against a healing AP champion (Soraka, Vladimir): GW from a different item class (Morellonomicon, Oblivion Orb) is appropriate. Thornmail specifically excels when both problems exist in the same target.

Bramble Vest Timing — First Back When Healing Is Immediate

If the enemy healing threat is relevant from level 1 (Nasus with Vampiric Scepter, Yasuo with Bloodline rune, ADC with Immortal Shieldbow rush), Bramble Vest at 800g on first back applies GW immediately without waiting for full Thornmail completion. Bramble Vest’s early THORNS variant fires GW on every incoming basic attack, reducing the healing efficiency of every trade from the first back purchase. The 800g spent on Bramble Vest is fully converted into Thornmail at completion — zero gold waste for the timing advantage.

Second Item Timing

Most tanks purchase Thornmail as a second item, after a first item that establishes the base defensive type (Sunfire Aegis for dual armor, Force of Nature for MR against mixed compositions, Warmog’s for HP). At second item completion (typically minute 15–20), the enemy ADC has their first lethality or life steal item and the healing threat is fully online — Thornmail’s GW fires on every subsequent basic attack against the tank for the rest of the game.

💡 Synergies

Best Paired Items

• Sunfire Aegis: Sunfire provides +35 armor that directly increases THORNS damage (10% × 35 = +3.5 per hit) while adding immolate AoE. More importantly, the combined armor from Thornmail + Sunfire (75 + 35 = 110+ bonus armor) creates a total bonus armor value where THORNS reflects 31+ magic damage per hit at minimum — and Sunfire’s immolate fires simultaneously in the same 0.5-second combat window. The tank who stands near physical attackers deals both Sunfire AoE fire damage and THORNS reflect magic damage from the same proximity.
• Frozen Heart: Frozen Heart adds +70 armor and its WINTERS CARESS aura reduces nearby enemy attack speed by 20%. The armor increases THORNS damage (10% × 70 = +7 per hit, total ~34.5 at purchase) while the attack speed reduction slows the rate at which enemies can generate THORNS procs — however, slower attack speed also means fewer procs per second for the carrier’s THORNS DPS. The combination is correct when the armor value and attack speed reduction are worth more than the slightly reduced THORNS proc rate.
• Randuin’s Omen: Randuin’s active slow clusters enemies near the Thornmail carrier, maximizing the duration of melee proximity during which THORNS fires. Every auto landed while the Randuin’s slow prevents kiting is another THORNS proc and GW refresh. Additionally, Randuin’s critical strike damage reduction and bonus armor (+80 armor) contributes to THORNS scaling — the two armor items combine for 155+ bonus armor, bringing THORNS reflect to 20 + 15.5 = 35.5 per hit with both items.
• Dead Man’s Plate: Dead Man’s Plate’s +45 armor adds to THORNS scaling while SHIPWRECKER’s movement-based momentum empowered attack synergizes with the tank’s approach pattern. Combined armor from DMP + Thornmail: 75 + 45 = 120 bonus armor at minimum, THORNS at 20 + 12 = 32 per hit. Dead Man’s Plate is the preferred second armor item when the game additionally requires the tank to have gap-closing mobility and a burst physical attack alongside the sustained THORNS reflect pattern.

Champion & Ability Synergies

• Rammus W Defensive Ball Curl + THORNS stacking: As analyzed in the champion examples section, Rammus W adds substantial temporary bonus armor that directly scales THORNS. At W rank 5 with Thornmail + one additional armor item (say Frozen Heart for +70 armor): base Thornmail 75 + Frozen Heart 70 + W bonus 200 = 345 bonus armor. THORNS fires for 20 + 34.5 = 54.5 magic damage per hit during W. Against a 1.2 attack-speed ADC attacking Rammus during W: 54.5 × 1.2 = 65.4 magic DPS from THORNS alone during the W window — and Rammus’s independent W reflect damage stacks on top of this.
• Leona Eclipse (E) + THORNS during stun window: Leona’s E Shield of Daybreak stuns the target — during the stun, the target cannot auto-attack. However, before the stun when the target is still attacking, and after the stun when they resume attacking, every auto triggers THORNS and reapplies GW. Leona’s CC chain (E stun → Q empowered attack stun) denies auto-attacks briefly but the THORNS GW immediately reapplies once the stun expires and the attacker resumes basic attacks.
• Cho’Gath Passive Carnivore healing interaction: Cho’Gath’s Carnivore passive heals him when enemies die near him — this is not a basic-attack healing source and is unaffected by GW from THORNS. However, enemies attempting to kill Cho’Gath through basic attacks receive GW and have their own life steal reduced, making the Cho’Gath trade favorable: the enemy heals less from their attacks while Cho’Gath continues receiving full Carnivore passive healing from killed minions throughout the trade.

❌ Common Mistakes & How to Avoid Them

• Building Thornmail against non-healing physical threats: Thornmail is not a general armor item — it is specifically designed to counter physical damage + healing combined. Against Zed (physical assassin with zero healing), Thornmail’s THORNS GW applies to Zed but Zed heals nothing from basic attacks — the GW is wasted, and Sunfire Aegis or Frozen Heart provides more value through sustained armor + other utility. Check whether the primary physical threat actually heals before committing to Thornmail over a pure armor item.
• Thinking Thornmail counters AP healing champions on its own: THORNS only fires on basic attack on-hits — AP champions like Vladimir, Soraka, and Yuumi heal primarily through abilities, not basic attacks. Against these champions, Thornmail provides zero GW pressure because they never auto-attack enough to trigger THORNS. The correct GW source for AP healing is Morellonomicon (AP item), Oblivion Orb (cheaper), or Chempunk Chainsword (AD + GW for mixed builds). Thornmail vs Vladimir is a mismatch — Vladimir heals through Q spellcast, which THORNS never sees.
• Not buying Bramble Vest early against immediate healing threats: In matchups where the enemy healing is relevant from the first trade (Nasus with Vampiric Scepter, Yasuo with Bloodline + early life steal, ADC who rush Immortal Shieldbow), every trade without Bramble Vest applied GW is free healing for the opponent. Delaying GW until full Thornmail completion (typically minute 14–17) gives the healing champion 8–11 minutes of uncontested healing at full effectiveness. Bramble Vest at 800g first back applies GW from the moment it’s purchased, with zero gold waste on the path to Thornmail.
• Expecting THORNS to deal meaningful damage as the primary kill source: THORNS at 27.5–45 magic damage per hit is not a reliable kill mechanic — it’s a sustain-denial and attrition tool. A 2000 HP ADC attacked by Thornmail would theoretically take 54.5+ procs of 45 magic damage = approximately 2450 cumulative THORNS magic damage over the fight to die purely from THORNS. That’s unrealistic in a real fight where the fight rarely lasts long enough for 54 procs. Thornmail’s value is GW application and trade-disincentive, not burst or reliable DPS. Build it for the healing reduction, not for the reflect damage.
• Ignoring that Jax dodge, Blind, and Block prevent THORNS: Jax Counter Strike (E) causes Jax to dodge all basic attacks during the duration — THORNS does not fire on dodged attacks. Building Thornmail to specifically counter Jax as the primary physical threat provides zero THORNS procs during Jax’s E window, which is precisely when Jax is dealing most of his melee damage. Against Jax, Thornmail’s value is in the armor and GW outside the E window — not during E, where his attacks are dodged and THORNS cannot respond.

⚔️ Counter Items & Playing Against Thornmail

Counterplay Options for Attackers

• Dodge (Jax Counter Strike E): The cleanest THORNS counterplay — dodge prevents THORNS from triggering entirely during the dodge window. Jax building Thornmail as a counter-Thornmail tool doesn’t work because Jax’s own autos get dodged by his E anyway. From the attacker’s perspective, abilities that apply dodge or blind to the Thornmail carrier’s attacks (or the carrier’s attacks being dodged by Jax’s E) completely prevent the THORNS reflect from firing during those windows.
• Building Armor Penetration to Reduce Effective Auto Damage (Not THORNS): THORNS deals magic damage that is unaffected by the armor penetration the attacker builds. Lethality and % armor pen reduce the physical damage the attacker’s autos deal to the Thornmail carrier’s armor — but THORNS’s magic reflect bypasses the attacker’s armor penetration entirely since it’s outgoing magic damage from the carrier, not incoming physical damage. Building heavy lethality to deal more physical damage through the carrier’s armor does not reduce THORNS’s reflect.
• Hexdrinker / Maw of Malmortius: THORNS deals magic damage to the attacker. Maw of Malmortius provides a magic damage shield that absorbs incoming magic damage when HP falls below a threshold. Against a Thornmail tank, an ADC or fighter with Maw has a one-time absorption of the cumulative THORNS magic damage that would otherwise kill them in the final burst trade. The shield won’t prevent consistent THORNS proc accumulation throughout the fight, but provides a emergency buffer in the final HP range where THORNS DPS would otherwise be lethal.

Strategic Counterplay

The most effective strategic counter to Thornmail is kiting and keeping distance — Thornmail only fires on basic attack on-hit, meaning abilities and spells deal zero THORNS proc. An ADC or assassin who deals most of their damage through abilities (Ezreal, Cassiopeia, Lux) against a Thornmail tank receives far fewer THORNS procs than a standard auto-attack champion because their primary damage source never triggers THORNS. Against Thornmail-building tanks, ability-heavy champions are the natural softest counters — not because their damage is avoided, but because the reactive damage they receive in return is minimized by the low frequency of basic attacks they land compared to ability damage output.

Arena Mode — Significantly Different Item

Thornmail in Arena has two entirely new passive effects that don’t exist on the Summoner’s Rift version:

💡 Arena NEW EFFECT 1 — Offensive GW: In Arena, Thornmail applies GW not just when being attacked but when the carrier deals physical damage to enemy champions. This fundamentally changes Thornmail from a purely reactive item into an offensive GW tool in Arena — the tank who attacks first applies GW proactively rather than waiting to receive basic attacks. Against the pair’s healer (Soraka, Yuumi, even Warwick self-heal), the Thornmail carrier can apply GW by landing any physical ability before the healing window, preemptively reducing incoming heals.

💡 Arena NEW EFFECT 2 — Escalating GW to 80%: The second Arena-exclusive effect escalates GW from 40% to 80% healing reduction when the afflicted champion attempts to heal for over 60% of their maximum HP while continuously under GW. This effect specifically targets high-burst-heal compositions that attempt to recover from near-death in Arena — champions who stack large single-heal abilities (Dr. Mundo Maximum Dosage, Soraka Wish, Olaf Ragnarok) while already under GW will trigger the 80% escalation if the heal would restore more than 60% of their max HP. The 80% reduction makes those large heal moments nearly irrelevant, directly countering Arena’s notorious high-sustain builds.

FAQ

Q: Does THORNS apply GW to the attacker even if the attacker is under Kayle R invulnerability?

A: Yes — GW applies to the attacker even if they are protected by a shield or invulnerability. Xin Zhao’s R invulnerability, Kayle R invulnerability, a Locket of the Iron Solari shield — none of these prevent GW from being applied to the attacker when their auto triggers THORNS. The invulnerability or shield reduces the THORNS magic damage (since it’s absorbed by the shield or negated by invulnerability), but GW is applied to the attacker’s healing regardless.

Q: Does Thornmail’s THORNS stack with other THORNS sources like Bramble Vest or Sunfire Aegis?

A: Bramble Vest is a component of Thornmail 2014 when Thornmail is completed, Bramble Vest THORNS is replaced by Thornmail full THORNS passive (the stronger version). They do not stack because Bramble Vest upgrades into Thornmail. Sunfire Aegis immolate damage is entirely independent of THORNS 2014 both fire simultaneously during melee combat but from separate passive sources. THORNS from a completed Thornmail and Sunfire immolate are additive 2014 both apply in the same fight window.

Q: Does THORNS deal damage through enemy shields?

A: THORNS fires in response to a basic attack on-hit — it deals magic damage to the attacker. If the attacker has a magic damage absorbing shield (Banshee’s Veil passive, Edge of Night NIGHTSHIELD), the first THORNS proc may be absorbed by the shield. However, since THORNS is not blocked by spell shield in some implementations, the exact interaction depends on the shield type. THORNS is documented as not being blocked by spell shield — Edge of Night’s spell shield specifically protects against the next ability, not reactive damage from items. For Banshee’s Veil passive, the shield absorbs the next damage from an ability or spell, but THORNS’s reactive damage classification as non-spell-effect proc may or may not interact with this.

Q: Is the 40% Grievous Wounds from Thornmail the standard GW reduction?A: Yes — standard Grievous Wounds reduces all healing and regeneration received by 40%. Thornmail applies standard 40% GW to champion attackers for 3 seconds per THORNS proc. If the attacker has multiple GW sources applied simultaneously, GW does not stack above 40% reduction on Summoner’s Rift — two GW sources both applying 40% results in 40% total, not 80%. In Arena exclusively, the second NEW EFFECT escalates GW to 80% when the target attempts to heal over 60% max HP while continuously afflicted — this escalation is Arena-only and does not apply on SR.