Combat Mechanics

Duration Damage Stacking and Refresh

Duration damage does not simply add every application together.

Standard explanation

When effects from the same attacker, damage type, and duration-damage source overlap, the stronger active damage per second is retained. Effects from distinct sources use separate entries and can overlap.

Deep explanation

  • Duration damage is grouped by damage type and attacker ID.
  • A matching duration-damage source key retains the stronger active damage-per-second value.
  • Different source keys append separate entries and stack while active.
  • The right and left equipment slots are distinct runtime sources; a shared skill, buff, or item keeps one strongest contribution.
Full duration damage per use = Σ(interval length × maximum active damage per second for the same source)
Damage per second from distinct sources = sum

Calculated results

Item Calculation Result
Same-source refresh 100/s for 4 s. After 1 s, 140/s for 3 s: 100×1 + max(100, 140)×3 520 total (not a stacked sum)
Distinct-source overlap 100/s for 4 s + 140/s from another key for 3 s, beginning after 1 s 820 total
Damage per second during overlap Same key: max(100, 140) 140/s

Published game data is 1.3.0.6. The binary evidence for duration-source aggregation was inspected in 1.3.0.4 and has not been re-audited against the 1.3.0.6 binary.

Analysis source: buildCalc/mechanics/formulas.json (local binary research for DurationDamageManager). No in-game measurements are published on this page yet.

Summary

Key point: Do not count a reapplication from the same skill as two stacked DoTs. Evaluate whether it can retain a stronger roll on refresh and whether another distinct source can be combined with it.