Mechanics Explained

Resistances come first

Resistances (Fire, Cold, Lightning, and Chaos) reduce incoming elemental/chaos damage before any other defensive layer. They start at 0% and cap at 75% by default — meaning at 75% Fire Resistance, a 100-damage fire hit deals 25. This is the single most impactful defensive stat in the game.

Resistances can go negative, which increases damage taken, and completing acts applies a stacking penalty, so you have to keep re-capping as you progress. Certain modifiers can raise your maximum resistance above 75% (toward 90%), which further reduces damage.

• Cap Fire/Cold/Lightning at 75% as your top defensive priority.
• Negative resistance increases damage — don't ignore a deficit.
• Max resistance can be pushed above 75% with the right modifiers.

Armor is good against small hits, bad against big ones

Armor mitigates physical hits, but the percentage it gives depends on the size of the hit relative to your Armor — it is not a flat number. The mitigation follows Armour / (Armour + 12 × damage taken), capped at 90%. The bigger the hit, the less your Armor helps.

Practically: roughly 50% reduction requires Armor about 12× the hit, and 75% requires about 36× the hit. So Armor shines against swarms of small attacks and is weak against a single huge slam — exactly the opposite of what new players often assume. (Patch 0.5 adjusted how some defenses scale, so verify current numbers against the live notes.)

• Armor only mitigates physical hits, not elemental/chaos.
• Effectiveness scales inversely with hit size — great vs many small hits.
• Formula: Armour / (Armour + 12 × damage taken), capped at 90%.

Evasion and Energy Shield

Evasion gives a chance to completely avoid Strikes and Projectiles (attacks and the spell equivalents). It uses an 'entropy' system rather than pure RNG to smooth out streaks. By default it doesn't help against area-of-effect hits unless you take the Acrobatics keystone, which extends evasion to AoE but heavily reduces your evade chance overall.

Energy Shield acts as an extra health pool that sits on top of life and recharges automatically — base recharge is roughly 33% per second, but only after you've avoided taking damage for about 2 seconds. Important caveat: Chaos damage removes twice as much Energy Shield, and Energy Shield doesn't protect against Bleed or Poison.

• Evasion: chance to fully avoid Strikes/Projectiles; weak vs AoE by default.
• Energy Shield: extra pool, ~33%/sec recharge after ~2 seconds undamaged.
• Chaos damage chews through Energy Shield twice as fast.

Hit damage vs damage over time

PoE2 treats a 'hit' and 'damage over time' (DoT) as separate systems, and this trips people up constantly. A hit is a single instant of damage that can be evaded, blocked, or partially shifted; DoT is recurring damage (like Ignite or Poison) that ignores most hit-avoidance.

This matters for defensive layering. For example, a modifier like 'X% of Physical Damage from Hits taken as Lightning' only applies to hits — not to a Bleed ticking on you. Conversely a 'Physical Damage taken as Fire' modifier (without the 'from Hits' wording) also applies to physical DoT like Bleed. Read the exact wording.

Ailments

Ailments are status effects applied on hit, and several are deadly if you don't account for them. The main ones: Bleed (physical DoT that ticks much harder while you're moving), Ignite (fire DoT), Poison (chaos DoT), Shock (you take increased damage), Chill (you move/act slower), and Freeze (you're immobilized).

You counter elemental ailments through your resistances and ailment thresholds, and you can use Charms (the PoE2 equivalent of utility flasks) to remove or prevent specific ailments. Note Bleed and Poison bypass Energy Shield and hit your life directly.

• Bleed ticks far harder while moving — stand still or stop it.
• Shock increases damage you take; Freeze locks you in place.
• Charms can remove/prevent ailments — slot them for your weak spots.

Life, leech, and recovery

Life scales from leveling, Strength, and gear. A common beginner mistake is building only damage and ending up with a thin life pool plus one weak mitigation layer — survivability is a stack of layers (capped resistances + life/ES + a mitigation type + ailment coverage), not a single stat.

Recovery (life/mana flasks, leech, regen) keeps you topped up between hits. Patch 0.5 nerfed several leech mechanics, so if you're copying an older life-leech build, confirm the leech still works as written before relying on it.