Applying an effect has two sides
Effect Hit Rate, often shortened to EHR, helps a Character apply effects that use a base-chance check. Effect RES works on the receiving side, reducing the chance of susceptible effects being applied. One improves application; the other resists it.
EHR is not ordinary attack accuracy or CRIT Rate. An attack can deal damage while failing to apply its associated debuff. Effect RES is also different from Elemental RES: resisting a debuff and reducing elemental damage are separate questions. Neither stat cleanses a debuff that is already present.
“Base chance” is the starting point
A listed base chance is adjusted by the applying unit’s EHR and the target’s applicable resistances. Even a 100% base chance can therefore fail. The number in the ability description is not always the final chance against the enemy in front of you.
A familiar example: Exposed
Pela’s Ultimate has a 100% base chance to apply its DEF-reducing Exposed effect. That wording still allows resistance to matter. Read the full ability in Pela’s Kit, rather than interpreting “100%” as an unconditional guarantee.
Fixed chance is different. EHR does not raise that stated probability. Clara’s Kinship Trace, for example, has a 35% fixed chance to remove a debuff from herself when attacked. Adding EHR does not make that cleanse more reliable. Do not apply the base-chance calculation to every percentage you see in a Kit.
Multiply the chances that survive each check
For a standard base-chance effect, start with its base chance and multiply by 1 + EHR. Then multiply by 1 − Effect RES and, when applicable, 1 − resistance to that specific debuff. Use percentages as fractions: 50% becomes 0.5. The final probability cannot exceed 100% or fall below zero.
The terms multiply; you do not simply add EHR to the ability’s percentage and subtract resistance. With an 80% base chance, 50% EHR and an assumed 20% target Effect RES, the calculation is 0.8 × 1.5 × 0.8 = 0.96. That gives a 96% chance if no additional resistance or special rule applies.
This is a model for ordinary base-chance application. Explicit immunity, fixed-chance rules and ability-specific exceptions must be handled on their own terms. It is not a promise that every game effect uses the same check.
The target changes the answer
These are hypothetical calculations for a single standard application, with no additional specific resistance. The resistance values are stated assumptions, not a claim about every enemy or a recommendation for one universal build.
Scroll horizontally to see all columns.
| Base chance | EHR | Assumed Effect RES | Final chance |
|---|---|---|---|
| 100% | 0% | 20% | 80% |
| 80% | 50% | 20% | 96% |
| 100% | 50% | 40% | 90% |
| 100% | 70% | 40% | 100% |
The last row reaches the probability ceiling for those assumptions. It does not prove that 70% EHR guarantees every effect on every enemy. Change the ability’s base chance or the target’s resistance and the amount needed changes too.
Specific protection is narrower than Effect RES
A Kit can grant resistance specifically to Crowd Control or another stated effect category. Read that scope literally. Lynx’s Exploration Techniques Trace, for example, protects against Crowd Control debuffs; it is not the same wording as a broad Effect RES increase.
Separate resistance terms are not simply added together. In a hypothetical check with 100% base chance and no EHR, 50% Effect RES and 50% applicable specific resistance leave a 25% application chance: 1 × 0.5 × 0.5. They do not add up to universal immunity.
Prevention also differs from removal. If the effect has already landed, use a response that can remove it. Buffs, Debuffs & Cleansing explains that distinction and its practical limits.
Build for the effect you need to land
Start with the exact ability and its current level. Check its base chance, whether the effect is central to the team, and the resistance assumptions behind any recommended target. A target without those assumptions is missing the explanation that makes it useful.
Include applicable in-battle bonuses. Pela’s The Secret Strategy Trace grants allies EHR while she is on the battlefield; equipment alone may not describe the whole check. Relic stats and Light Cone abilities are parts of that total, not separate guarantees.
Once one application reaches its ceiling, extra EHR cannot raise that probability above 100%. It may still serve another lower-chance effect or an explicitly stated stat-conversion passive. Check the whole Kit before deciding that more is always useful or always wasted.
Diagnose application before changing the build
If a debuff fails, distinguish a resisted application from an unmet trigger, an immune target or an effect that already expired. More EHR only addresses the appropriate chance check. It cannot supply a missing trigger or extend the effect’s duration.
For a specific Character, use the Kit and Guide tabs to connect these rules to their actual abilities. This guide explains why a target exists; those pages provide the Character context needed to apply it.