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How damage is calculated

Player guide
8 minute read
How damage is calculated

A practical reading order for damage, including which inputs belong to the attacker, the skill, and the target.

By RO Codex Team Updated
Start with the attack profile

A damage result is only meaningful when the attack profile is explicit. Record whether the hit uses Physical ATK or Magic ATK, the skill level, its listed multiplier, hit count, element, and any weapon or target restrictions. A multi-hit skill should be compared both per hit and per cast so a fast animation is not mistaken for a larger multiplier.

Review these inputs separately so you can tell whether an upgrade changed the character sheet, the skill coefficient, or a later damage multiplier instead of hiding everything inside one total.

  • Confirm the skill level and displayed damage percentage.
  • Check element, range, cast time, cooldown, and number of hits.
  • Use the same buff state for every build being compared.
Apply target properties next

Choose the actual monster you plan to fight. Physical DEF and Magic DEF affect different attack profiles, while race, size, element, and monster class determine whether target-specific bonuses apply. A build that wins against a neutral training target may lose against an MVP with different defenses or reductions.

When a modifier names a target, keep that qualifier attached. Demi-Human Damage, Fire Damage, and MVP Damage are not interchangeable general bonuses.

Read the result in stages

Compare base attack, skill scaling, additive bonus groups, multiplicative groups, defense and resistance adjustments, critical handling, and final damage. Rounding can occur between stages, so two mathematically similar builds may differ slightly in the game.

Worked checkpoint
If a skill is 600% and hits three times, first verify whether 600% is applied to every hit or distributed across the cast. Then apply the target profile and qualified bonuses. Do not simply multiply the final screen value by three without checking the skill’s listed behavior.
Use repeatable comparisons

Change one input at a time, keep the target fixed, and compare average hit, critical hit, damage per cast, and time to kill. This makes the source of an improvement visible and protects against stacking a bonus that the chosen target cannot activate.

Sources and evidence

This guide is based on the following player-facing evidence. Read the data quality standards for accuracy commitments and known limitations.

Skill catalog details
Published coefficients, timing, range, hits, and targeting rules define the selected attack.
Monster catalog details
Race, size, element, HP, Physical DEF, Magic DEF, and reductions provide the target profile.
Controlled comparison inputs
The same character state, target, and activation conditions are used for each compared result.
All guides Data quality standards