Effect Hit Rate Calculator
Determine the probability of applying debuffs, status effects, or crowd control on enemies in RPGs based on your stats and enemy resistance.
Real Hit Probability:
0%
Status Outcome:
–
EHR Needed for Guarantee:
0%
Formula: Real Chance = Base × (1 + EHR) × (1 – Effect RES) × (1 – Debuff RES)
Understanding Effect Hit Rate Mechanics
In many turn-based RPGs (like Honkai: Star Rail or Epic Seven), applying a debuff isn't as simple as the skill's description suggests. The "Base Chance" is merely the starting point. The actual outcome is determined by a conflict between the attacker's Effect Hit Rate (EHR) and the target's Effect Resistance (Effect RES).
The Hit Rate Formula
The standard formula used in calculating the real probability of landing a status effect is:
Real Probability = Base Chance × (1 + Attacker EHR) × (1 - Target Effect RES) × (1 - Target Debuff RES)
Key Metrics Definitions
- Base Chance: The probability listed on the character's skill tooltip. Note that if a skill says "Fixed Chance," it usually ignores this formula and cannot be modified by EHR.
- Effect Hit Rate (EHR): A stat built on the attacking character via equipment (relics, light cones) or traces. It acts as a multiplier to the base chance.
- Effect RES: The enemy's innate resistance to status effects. High-level bosses often have 30% to 50% Effect RES.
- Debuff RES: A specific resistance to certain types of crowd control (e.g., Frozen RES, Entanglement RES). This is calculated separately from general Effect RES.
Example Calculation
Let's say you are using a character with a 100% Base Chance to freeze an enemy.
- Your Character's EHR: 50%
- Enemy Boss Effect RES: 40%
The calculation would be:
1.00 × (1 + 0.50) × (1 - 0.40) = 1.00 × 1.5 × 0.6 = 0.9
Even with 50% extra hit rate, you only have a 90% real chance to land the debuff against a resistant boss.
Why You Need 100% Real Hit Chance
For debuffers and dot-appliers, missing a turn of application can result in a significant loss of damage or crowd control. To guarantee a hit against an enemy with 40% Effect RES using a 100% Base Chance skill, you would generally need around 67% EHR.