Critical hits

Critical hits are melee hits that do critical damage. Critical damage is damage that is usually double normal damage.

How it works
From a Daybreak forum post by niente, EQ Developer, April 11, 2019 (SPA refers to SPell Affect):

Here's an explanation of how critical hits work:

If it's an NPC

- NPCs can't crit except for pets

- Get the leader's SPA 218 (pet crit chance)

- If we roll within that chance, use default crit mod (170%)

- Add SPA 474 (pet crit mod), 330 (crit base dmg %), 496 (crit base dmg % - non stacking)

*** - If the leader has luck, roll for an additional crit mod bonus

- Add 5 damage

- Multiply crit mod, damage done

If it's not an NPC

- if it's a level 12+ WAR/BER, RNG using archery, or ROG using throwing, they can crit

- get total SPA 169 (crit chance)

- if it's possible for us to crit (meet above qualifications or have some amount of crit chance SPA), roll:

- get SPA 219 (Slay Undead)

- If NPC is undead

- If PC has a buff or AA with Slay Undead, get crit mod from that spell

- if we qualify for the Slay Undead roll:

- add 5 damage, multiply by the SPA 219 mod (from AA or Holy Forge)

- get attacker and defender DEX mod:

- if DEX > 255 anything higher returns 20% of its value

- add 45

if attacker is not in (WAR, BER/ROG not throwing, RNG not using archery)

- multiply DEX mod by 3, divide by 5

- multiply DEX mod by total SPA 169

roll from 1 to 3400 (archery), 1100 (throw), 8900 (everything else)

if roll is less than DEX mod, we crit

- add 5 damage

- using default crit mod (170%)

- add SPA 330, 496

- roll luck for additional crit mod bonus

- multiply dmg by mod

- if victim is an NPC and attacker has SPA 440 (Finishing Blow) and victim is the right level

- get finishing blow chance, roll

- using max % HP possible to be done by this rank of Finishing Blow, if NPC is low enough HP, get the DMG from Finishing Blow

- if attacker is a ROG standing behind the victim

- chance = ROG's level * 12 // ROG have 100% chance to Deadly Strike from behind at lvl 100

- roll 1000, if it's less than the chance, multiply damage by 2

- get total SPA 171 (Crippling Blow)

- roll 100, if it's less than SPA 171 we get a Crippling Blow

- if attacker is a PC using Holy Forge and victim is undead, 20% chance of getting a Crippling Blow

- if attacker is in a berserk frenzy or got a successful Crippling Blow from Holy Forge

- add 19% damage

- calculate chance to resist bash

- if you roll successfully, stun victim 2 seconds

- if it's not a Deadly Strike, set the critical hit flag

- otherwise, calculate assassinate chance:

- if we have SPA 345 (Assassinate max level), the victim is humanoid, and the attacker is at least 60

- get chance to assassinate - (DEX capped at 255)

- add 5

- add SPA 349 (Assassinate)

- roll 1000, if we were successful get dmg from SPA 349 (Assassinate base 2)

- cap dmg at 6000000