Updated 2026-09-27
한국어Effect
Arcane AcuityArcane Acuity increases spell attack rolls and spell save DC according to its remaining stacks.
If your equipment grants stacks from weapon attacks, attacking before casting can help. The action that grants stacks depends on the item.
Taking damage reduces its remaining duration. Even after building stacks, being hit before casting can reduce the bonus.
Core rule
Attack rollsAn attack roll decides whether an attack hits. The total must meet or exceed the target’s Armour Class.
Roll a d20 and add the applicable ability modifier, proficiency bonus, and other attack bonuses. The weapon or spell determines which ability applies.
Damage is calculated after the hit is decided. A larger attack-roll total does not itself deal more damage.
Core rule
d20 rollsA d20 has twenty possible results, from 1 to 20. It is used to resolve attacks and many uncertain actions.
Add the relevant ability modifier, proficiency, and other bonuses to the die. Meeting the target number is enough to succeed.
Attack rolls, saving throws, and ability checks use different bonuses. A bonus to one does not automatically apply to the others.
Core rule
Saving throwsA saving throw determines whether you resist or avoid a harmful effect, such as a spell or trap.
Roll a d20 using the ability named by the effect, then add the relevant modifier and saving-throw bonuses. Meeting the Difficulty Class succeeds.
Success may mean half damage or avoiding the effect entirely. A successful save does not always mean zero damage.
Answer
When an item's specified trigger is met, it applies Arcane Acuity.
Based on in-game textConditions vary by item. Check the original passive of the item that applies it.
Answer
Each remaining stack grants a bonus to spell Attack Rolls and spell Difficulty Class.
Derived from game dataMAG_GISH_ARCANE_ACUITYAffected entity has a +1 bonus to its spell
Reduce the duration by 2 each time the entity takes damage.
Core rule
Repeated effects may grow stronger, last longer, replace one another, or fail to combine.
For conditions such as Radiating Orb, remaining turns also affect strength. In contrast, repeated resistance does not keep halving damage.
Check whether the effect stacks and whether it has a cap. A shared display name does not mean the values from every variant can be added together.
Answer
The game data below distinguishes an entry's listed duration from the duration actually applied.
Derived from game dataMAG_GISH_ARCANE_ACUITYAffected entity has a +1 bonus to its spell
Reduce the duration by 2 each time the entity takes damage.
Answer
After building it up, use it with spells that use spell Attack Rolls or require Saving Throws; also account for its duration being reduced when the bearer takes damage.
Codex commentary