Byrth's WS Damage Guide

From FFXI Wiki

All types of Physical Damage rely on a multiplication of the same three main factors, though the specifics of each term change depending on the specifics of the attack.

Damage = Base Damage×fTP×pDIF×Additional Factors

Base Damage

Base Damage is composed of three components:

  • Weapon Damage - The Damage listed on the weapon being used
  • WSC - The contribution of modifiers that affect the attack, attenuated by a level correction factor (α).
  • fSTR - Depends on the attacker's STR, defender's VIT, Attack Type, and Weapon Rank.

Weapon Damage

Two-handed and Ranged weapons/Weapon Skills typically have higher base damage than 1-handed Weapons/Weapon Skills, because they have comparable (or higher) WSC and higher Weapon Damage.

Example: Tachi: Fudo does better damage than Rudra's Storm. Though they have comparable fTP and similar modifiers, Tachi: Fudo has much higher Weapon Damage. (Masamune's D132 vs. Twashtar's D55)


Generally Weapon Skills will have at least one stat that effects the base damage of the Weapon Skill, and that stat will contribute a certain amount of base damage per amount of stat. Though the meaning of the abbreviation has been lost, WSC refers to this contribution to base damage. Additionally, SE introduced a factor known as α that would scale (decrease) the effect of base stats on weapon skill base damage. It is not incredibly clear from a balance- or logic-based perspective why they would feel this is necessary, but it exists. For level 75 and above, α is just 0.85. See the WSC page for more information.

Example: Tachi: Gekko has a 75% STR modifier and you have 140 STR in your WS gear on your level 80 SAM.
floor( 140×0.75 ) = 105, before applying α
floor( 105×0.85 ) = 89 base damage added to Gekko from WSC


fSTR is a term that awards you base damage if your STR is greater than the monster's VIT. It can also penalize you and reduce your base damage for having less STR than the monster's VIT, but you need to be substantially below it for this to really happen. The fSTR calculation are different ranged and melee weapons, with ranged weapons gaining and losing base damage twice as fast (1 base damage every 2 STR) as melee weapons (1 base damage every 4 STR). See the fSTR page for more specific details.

When thinking about fSTR, it is important to understand two things:

  • fSTR caps at floor(Weapon Damage÷9)+8 for melee weapons or 2×floor(Weapon Damage÷9)+8.
  • fSTR can be treated as a 30% (melee, 0.25/α) or 60% (ranged, 0.5/α) STR modifier until it caps.
Example: Coronach is 40% AGI and 40% DEX modded, but the best single stat to stack for it is actually STR due to fSTR at least until you cap. A level 99 Annihilator has 76 base damage, so that would cap at 32 fSTR (76÷9+8)×2, which is approximately 60 more STR than the enemy's VIT. On high level monsters, you may never hit that without STR buffs.


fTP is the second major factor in calculating damage. It is a damage multiplier that depends on the specific Weapon Skill and any potential equipment modification (Elemental Belts and Elemental Gorgets). See its main page for the specifics of calculating fTP.

There are currently two ways the term "fTP" is used in FFXI conversations these days:

  • Formal: To represent the base damage multiplier of the first hit.
  • Informal: To represent the total effective damage multiplier, including extra hits and additional attacks.

Most Weapon Skills only give their WS-specific fTP to the first hit, and all additional hits, DAs, TAs, etc. receive the base damage bonuses from WSC but are not multiplied by any extra factor like fTP. There are some exceptions to this rule, but it is typically true. Not being multiplied by anything is the same as being multiplied by 1, so it is somewhat typical to sum all additional hits into one term, each with an fTP of 1.

Example: Insurgency is a 4-hit WS with a first-hit fTP of 0.5. On a Dark Knight with 0% Double Attack/Triple Attack, this could be considered to have a total fTP of 0.5+1+1+1 = 3.5.
With 20% Double Attack (can proc twice per 2+ hit WS), you would have an effective fTP of 0.5+1+1+1+0.2×1+0.2×1=3.9.

Something to consider... 1-handed Weapons Skills generally rely on high fTP to balance out their low Base Damage.

Example: Asuran Fists has paltry 10% STR and 10% VIT mods, but it remained a solid Hand-to-Hand Weapon Skill for years because of its high fTP (8.0).


pDIF is the loud, messy uncle that no one likes. It takes our pretty model of exact values and turns it into a range of damages through a randomization function. To make it worse, the randomization function used and particulars of it are different depending on a variety of factors. This function is based on:

  • Attack Type - See second important thing below. This determines which specific pDIF equation is used.
  • dLvl - The difference between the defender's level and attacker's level (doesn't matter if it is negative, but gives a penalty if it is positive).
  • Attacker's Attack ÷ Defender's Defense - Also known as "Ratio"
  • Critical Hit - Does the swing in question Crit or not?

The first important thing to know about pDIF is that a percentage increase in attack will increase your overall damage by very approximately the same percentage until it caps. So if you have 800 attack without food and 880 attack with food, you can expect to gain about 10% damage. Specifically, you will gain less than 10% damage on critical hits but more than 10% damage on regular hits. The higher the monster's level is, the more you gain from attack.

The second important thing to understand is that the Attack/Defense Ratio can cap. It does so at different times for different weapon types:

  • 1H - Caps at 2.0 Ratio
  • 2H - Caps at 2.25 Ratio
  • Ranged - Caps at 3.0 Ratio

If you are a 1H user fighting a monster with 300 Defense and you have 600 Attack (Ratio=2), going up to 1200 Attack will not affect your damage dealt at all. This is true regardless of the monster's level, so you can't somehow overpower level correction.

Additional Factors

This is the catchall category for things like piercing damage bonus, Critical Attack Bonus, etc. At the moment, it is assumed they are all applied after pDIF. It has been proven that Piercing Damage Bonus is applied after pDIF is floored (you will never see a number that ends in 4 or 9 with 25% piercing bonus and no other Additional Factors). Here is a brief list:

These are multiplied with your damage based on the particular situation.

The End

That's all for now. At some point I should add a complete example to this. --Byrthnoth 09:49, 12 April 2012 (EDT)