Combat
Combat resolution lives in common/src/combat.rs (~4200 lines) and runs inside the server ECS's CombatSystem — see Server architecture. Everything goes through Attack::apply_attack: a single entry point that resolves hit/miss, damage, poise, buffs, and side effects for any attack, whether it's a martial swing or a spell.
Balance numbers (base probabilities, curves, caps) aren't hardcoded in Rust — they live in the assets/common/combat_tuning.ron asset (CombatTuning), cached and re-read on every apply_attack. These are first-pass numbers (BL-52) subject to retuning from telemetry, same as class_attributes.ron — see Classes.
Hit resolution: accuracy vs evasion
A single-target attack (AttackSource::Melee or Projectile) rolls a hit check before any damage is applied:
hit% = clamp(base_hit + (accuracy − evasion) · hit_k, hit_floor, hit_ceil)
With the current combat_tuning.ron values:
| Constant | Value | Meaning |
|---|---|---|
base_hit | 0.85 | hit% when accuracy == evasion |
hit_k | 0.015 | +1.5pp of hit% per net point of advantage |
hit_floor / hit_ceil | 0.05 / 1.0 | never below 5% miss chance; optimal investment can guarantee a hit |
Magic attacks (any ability whose AbilityMeta.source is set) roll magic_accuracy against magic_evasion; physical attacks use accuracy/evasion. The target's physical evasion also adds a contribution from equipped armor (compute_armor_evasion): heavier armor lowers it, going unarmored maximizes it (gear_evasion_cap: 12.0, gear_evasion_floor: -10.0, a flat -2.0 if the target is carrying a shield). Both stat pairs (physical and magic) are per-class/level curves defined in class_attributes.ron — see Classes.
A miss (attack_missed) cancels damage and hostile effects entirely — the same gate an active dodge uses — and shows a "Miss" floater over the target. A spell that misses simply fizzles, with no further penalty.
AoE never rolls to-hit. Beam, Shockwave, Explosion, Arc, and Pool auto-hit the radius and are mitigated passively via typed elemental resistance (aoe_resistance, soft-capped at 75% so stacked resistance can never reach immunity) — the multi-target hot path stays RNG-free by design.
Resisted effects like charm/domination/banishment (power_word_divine_word) use a separate saving-throw roll, saving_throw_chance (caster magic_accuracy vs the target's effective magic_evasion, adjusted by magic resistance and a -20pp penalty if the target is already fighting the caster). It's the same function for any future resisted effect — there's no second curve.
Crits and positional precision (backstab)
A single-target attack that lands can roll a critical hit:
crit_chance = clamp(Stats::crit_chance, crit_chance_floor, crit_chance_cap)
crit_chance_floor = 0.03 (nobody has 0% crit) and crit_chance_cap = 0.75 for random rolls — the base multiplier is crit_damage_mult = 1.5, further scaled by the caster's gear precision_power.
On top of that, the engine has a guaranteed positional critical that replaces the random roll when it applies: hitting a target's back or flank (based on the angle between its Ori and the attack direction), a poised/stunned target, or a few other conditions (ImminentCritical, precision vulnerability). precision_mult_from_flank in common/src/combat.rs:3213 defines the angles and multipliers:
| Zone | Angle | Base multiplier |
|---|---|---|
| Backstab | < 45° (FULL_FLANK_ANGLE) | MAX_BACK_FLANK_PRECISION = 0.75 |
| Side flank | < 135° (PARTIAL_FLANK_ANGLE) | MAX_SIDE_FLANK_PRECISION = 0.25 |
| Frontal | ≥ 135° | no positional bonus |
These multipliers are further scaled by FlankMults (back/front/side), which a weapon or passive can adjust — and by precision_flank_invert, which flips which side of the target counts as "back" (used by abilities that reward frontal attacks, e.g. duelist-style kits). If no positional condition fires, it falls back to the random crit_chance roll described above — the two are mutually exclusive, not additive.
Poise and stagger
Poise (common/src/comp/poise.rs, the Poise component) is a bar separate from health that, once emptied, interrupts the target. PoiseState has 5 states:
| State | Threshold (POISE_THRESHOLDS) | Stun duration | Poise→health damage multiplier |
|---|---|---|---|
Normal | — | — | — |
Interrupted | 50 | 200ms + 200ms recover | 0.1 |
Stunned | 30 | 350ms + 350ms recover | 0.25 |
Dazed | 15 | 750ms + 750ms recover, movement at 20% | 0.5 |
KnockedDown | 5 | 1.5s + 1.5s recover, movement at 0%, 10.0 knockback impulse | 1.0 |
After a poise-break, POISE_BUFFER_TIME (1 second) protects the target from taking poise damage again immediately. Poise damage comes from two paths: an attack's CombatEffect::Poise(f32) field, and — passively — Crushing damage, which converts part of the damage absorbed by armor into extra poise (CRUSHING_POISE_FRACTION = 1.0), scaling with how armored the target is.
compute_poise_resilience gives the poise-damage reduction from equipped armor; sufficiently heavy armor can make an entity fully immune to poise damage.
Damage kinds
DamageKind (common/src/combat.rs:2498) splits physical from magic/elemental, and some kinds carry their own secondary effect applied inside apply_attack:
| Kind | Category | Secondary effect |
|---|---|---|
Piercing | physical | ignores part of armor's protection (PIERCING_PENETRATION_FRACTION = 0.75) |
Slashing | physical | drains the target's energy (SLASHING_ENERGY_FRACTION = 0.5); any shortfall converts to health damage |
Crushing | physical | extra poise damage (see above); content alias Bludgeoning |
Energy | legacy | generic magic catch-all, mitigated generically |
Acid, Cold, Fire, Force, Lightning, Necrotic, Poison, Psychic, Radiant, Thunder | magic/elemental | content taxonomy (ENG-A2); Necrotic and Radiant are meant as opposite poles, with the affinity interplay still unimplemented |
Buffs and debuffs
An attack's effects beyond raw damage live in CombatEffect (common/src/combat.rs:1736): Heal, Buff/SelfBuff (applies a CombatBuff to the target or the attacker itself), Knockback, EnergyReward, Lifesteal, Poise, Combo, AdditionalDamage, RefreshBuff (refreshes a buff kind's duration with some probability), Energy, Transform (temporary transformation into another entity), and DebuffsVulnerable (bonus damage scaling with the target's active debuff count).
The buffs/debuffs themselves (BuffKind, common/src/comp/buff.rs) are a broader catalog — Regeneration, Shielded (absorb shield), ProtectingWard, Frenzied, Hastened, FreedomOfMovement, and several more — each with its own strength curve. This page doesn't enumerate them exhaustively; they belong as much to the magic and consumables systems as to combat — see Magic for the casting side.
Which requirements gate an effect (CombatRequirement, e.g. TargetPoised) and how they're modified (CombatModification) are the same generic framework used by martial and spell attacks alike — there's no separate buff system for magic vs. melee combat.