Combat Mechanics - Stats, Damage Types and Stacking Effects

The stat core

StatType covers 104 distinct stats — from core Health/Stamina/Concentration tri-resource to regen variants, Encumbrance, attack speed and conditional crit stats. Runes.Stat adds another 120 endgame-only affixes. The in-game strings include the full affix phrasing table (% Crit Chance vs. Burning, % Damage vs. Full Health, …), confirming these roll on gear.

Damage and elements

DamageType has 13 entries (Physical, Magic, Strike, Thrust, Blunt, Fire, …) crossed with Element (Fire, Ice, Poison, Shock, Ether, Rage, Earth). MonsterDefences carries per-type defence icons, so monsters visibly telegraph their resistances — check the icons before committing to a spell school.

Stacking effects

StackingEffect lists 17 persistent conditions that stack and refresh: Burning, Chill, Rage, Poison, Shock, Bleeding, TreantBurning, SwordSwap and more. The passive tree and rune system both key off these — many passives trigger on conditions (% Crit Chance vs. Chilled exists because Chill is a designed crit window).

Spell combat

Spells (Spell enum, 258 entries) are learned from spellbooks (an item subclass), upgraded via SpellUpgradeEntry, cast through the spell bar with ground indicators (SpellShapeIndicator), and choreographed per class/race via SpellVideoChoreography. NetworkSpell replicates casts in co-op.

Co-op scaling

CombatSession groups players into shared combat contexts; MultiplayerDamageScaling adjusts monster stats per additional player. Party play also enables combo-style interactions via pet spell-effect rows.

Build implications (from data, not theory)

• Condition-on-condition design: Chill → crit window, Bleeding → execute passives — the 353 affix strings are the blueprint.
• Empowerment affixes (see the Monster AI guide) interact with your element choices; Frostbound elites punish ice-heavy parties.
• Encumbrance is a real stat — the Encumbrance rune affix and potions reference it; builds must manage it.