Hit chance

Table of contents

  1. Mechanics
  2. Formula
    1. Characters
    2. Monsters

Mechanics

Hit chance uses RNG arrays 36-42 for for party members (RNG36 for Tidus, RNG37 for Yuna, etc.), 43 for Seymour and all Aeons, 44-51 for monsters (RNG44 for the monster in slot 1, RNG45 for the monster in slot 2, etc.). It’s advanced once every time a character/monster uses an action that can miss (for characters its Attack and the Skills).

Formula

Characters

For characters the Hit chance is calculated as follows:

accuracy index = ((accuracy * 2 * 0x66666667) // 0xffffffff) // 2
(the above is similar to accuracy * 2 // 5)
hit chance index = accuracy index - enemy evasion + 10

if hit chance index < 0 then hit chance index = 0
else if hit chance index > 8 then hit chance index = 8

Then the game uses this table to find the Base Hit chance:

Hit chance index Base Hit chance
0 25
1 30
2 30
3 40
4 40
5 50
6 60
7 80
8 100 
hit rng = rng value MOD 101
if the character is affected by Dark:
    base hit chance = (base hit chance * 0x66666667 // 0xFFFFFFFF) // 4
    (the above is similar to hit chance // 10)
hit chance = base hit chance + user luck - target luck
every aim on the user adds 10 to hit chance
every reflex on the target subtracts 10 from hit chance
if hit chance > hit rng then the action hits

Monsters

For monsters the Accuracy Stat has no purpose, every monster action has an accuracy value that is used instead:

hit chance = action accuracy - target evasion
if the monster is affected by Dark and the action takes Dark into consideration:
    hit chance = (hit chance * 0x66666667 // 0xFFFFFFFF) // 4
    (the above is similar to hit chance // 10)
hit chance = hit chance + user luck - target luck
every aim on the user adds 10 to hit chance
every reflex on the target subtracts 10 from hit chance
if hit chance > hit rng then the action hits