Critical Hit Rate

==Overview==
Every time players swing at a monster, they have a chance to critical hit. If they successfully critical, the monster will take additional damage. This boost to damage is represented in two phases, an increase in pDIF, or effective Attack, and direct modification by Critical Attack Bonus and other similar abilities. Additionally, Critical Hits forced by Sneak Attack and Trick Attack with Thief main receive base damage bonuses from Dexterity and Agility respectively.
While all normal swings have the potential to critical, Weapon Skills can only critical hit if their descriptions read "chance to critical hit varies with TP." or an effects enables them to critical hit (ex. Shining One). This has been proven multiple times, though the easiest verification method is using 1-hit weapon skills and looking for damage that indicates a critical hit has occurred. It also appears that some weapon skills, though they possess the appropriate description, do not receive the benefit of base and gear Critical Hit Rate, like Blade: Rin.
*For melee weapons, critical hit rate is the sum of the base rate (5%), gear/atma (0-100%), merit points (0-5%), Buffs, Weapon Skill modifiers, and player Dexterity relative to target Agility (also known as dDEX, 0-15%). As there is no cap to critical hit rate, it can be taken all the way to 100%, guaranteeing that every attack is a critical hit. Category-specific caps are marked. It also only takes whole number values, so it is impossible to have something like a 12.5% Critical Hit Rate.
**Weapon Skills with the description "Chance of Critical Hit varies with TP" modify Critical Hit Rate during Weapon Skill. Generally, the base modification at 1000TP varies from 0% to 40%, and extra Critical Hit Rate is awarded for TP over 1000.
***Example: A Thief has 115 Dexterity, Level 5 Critical Hit Rate Merits, +4% Critical Hit Rate in gear, and is fighting a monster with 96 Agility. They have a 5% + 4% + 5% + 0% + 2% (dDEX=19) = 16% Critical Hit Rate.
*For ranged weapons, critical hit rate is the sum of the base rate (5%), gear/atma (0-100%), merit points (0-5%), Buffs, Weapon Skill modifiers, and player Agility relative to target Agility (also known as dAGI, no known cap). 
**Dexterity does not affect critical hit rate for ranged weapons.
===Melee Critical Hit Rate (dDEX)===
----
dDEX (Player DEX - Target AGI) determines the contribution of Dexterity to melee critical hit rate. This is added on to the base rate and merits to determine the total critical hit rate. Because this value depends on the target's Agility, which will be determined by its level and job combination, Critical Hit value changes significantly depending on target.
Based on the chart below, you can see that there is an extremely significant jump in critical hit rate when dDEX is increased from 40 to 50 (from 4% at dDEX=39 to 15% at dDEX=50), but no further boost to critical hit rate once dDEX is greater than 50.
{| border="1" cellpadding="0" cellspacing="0" BGCOLOR="#cee0f2" width="200px"	dDEX 	Crit Rate
 0-6 	 +0% 	
 7-13 	 +1% 	
 14-19	 +2% 	
 20-29	 +3% 	
 30-39	 +4% 	
 40-50	 +(dDEX-35)%	
==Merit Points==		
== Job Points ==
Critical hit rate is enhanced by the following effects:
*Rogue's Roll: Up to +27% critical hit rate depending on result, Phantom Roll+ equipment, and THF in pt or relic hat proc.
*Blood Rage: +20% critical hit rate while in effect.
*Impetus: Up to +50% critical hit rate with consecutively landed attacks.
*Mighty Strikes: 100% critical hit rate while in effect.
==Critical Hit Damage==
Critical Hit Damage is determined by Base Damage, fSTR, Critical pDIF, and the sum of modifiers such as Critical Attack Bonus job trait and the other Job Abilities/equipment that enhance it directly. The bonus is capped at +100% maximum total from all sources (abilities, traits, gear, atma, etc.). 
Equation: Critical Hit Damage = (Base Damage + fSTR) * Critical pDIF * (Sum of Direct Modifiers)
Critical Hit Damage is enhanced by the following effects:
*Critical Attack Bonus: +5~14% depending on tier of trait.
*Dead Aim: +10~45% depending on tier of trait, for ranged attacks, not including weapon skills.
*Impetus: Up to +50% with consecutive attacks landed while using Bhikku Cyclas +3
==Enemy Critical Hit Rate==
*Enemy critical hit rate is a merit category available to all jobs. It can be merited a total of 5 times. Each merit upgrade grants a 1% decrease in the rate of critical hits by enemies against the player. It costs 15 merits to fully upgrade (1>2>3>4>5). 
*Enemy Critical Hit rate seems to be calculated approximately the same as Player Critical Hit Rate, but using the Enemy's DEX and the Player's AGI. This means that, in situations where the Player has a large AGI bonus like Abyssea, the Enemy's critical hit rate is at the 5% unmerited Critical Hit Rate minimum. Merit points and Equipment can further reduce this, but it appears to have a 1% minimum.
**Equipment examples: Eluder's Sachet, Warden's Ring, Fortified Ring.
**For tanks considering how easy it is to go to 0 damage taken while under the effect of Phalanx it is worth considering items with this stat to reduce the spike damage of critical hits.
*Enemy Critical Hit rate appears to cap at 10%, regardless of how high the Enemy's DEX is. (Exceptions include status enhancements like Mighty Strikes or critical evasion enfeebles such as Stardiver or Feather Step).
==Enemy Critical Hit Damage==
* VIT plays a role in reducing enemy critical hit damage, but the specific effect is unknown.
** This effect is only on the player side, not for monsters.
* Reduced by Crit. Def. Bonus trait.
* Can be increased by equipping the .
==Related Links==
*Blade: Rin Testing (Xera, BG)
*DEX/Crit rate research (BG forums)
*AGI/Crit rate research (Melphina, Alla)
*More AGI/Crit rate research (Byrth, BG)
*Dexterity's Impact on Critical Hits
*May 2011 Version Update "VIT will play a role in calculating damage taken from critical hits."
*Monster Crit rate via dDEX (JP blog)
Category:Game Mechanics
Category:Game Terms
Category:Derived Stats