Armor Penetration (3.5e Variant Rule)
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Created by: Titan W
Original Post: http://boards1.wizards.com/showthread.php?t=669992
 Weapon and Armor Armor Penetration System:
This was inspired by a spur of the moment train of thought in another thread and while I was informed one already exists I decided to continue with this because It was already half finished and I was liking the way it was coming together. So have at it.
On an attack the difference between the weapons armor penetration score and an armor’s penetration resistance score is subtracted from the person’s damage, any negative value counts as zero.
In addition an attacker’s strength score is added to the weapon’s penetration ability. When the Power Attack feat is used the attacker gains a +2 modifier to their penetration score. When in a rage a barbarian gains a +1 to this score and on a sneak attack the rogue gains a +6 to this score.
Rough Equation For Values is:
(Weight)+(Attack Type Value)+ (Weapon Size Value)+(Bonus) = (Penetration Score)
Attack Type Value = Piercing +2 / Slashing +0 / Bludgeoning –2 (Weapons using 2 types simultaneously (Such as Morning Star) use the median of the two scores)
- Size Value = Tiny –4 Small –2 Medium 0 Large +2 etc..
- Weapons used Two-Handed have a +2 Bonus to this modifier when usually used one-handed.
- Bonus = Magic Bonus or +1 if masterwork Piercing weapon
- Light weapons have an additional –2 when used one-handed, this is not applied in the table.
- Weapons set against a charge have +2 Penetration
- Weapons used in a charge have a +2 penetration with an additional +2 for a mounted charge.
- Weapons made of Adamantium gain +3 to penetration
- Weapons made of Cold iron Gain +1 to Penetration
- Weapons made of Mithrail count as normal weight for Penetration
 The Tables
|Table 1-1: Simple Melee Weapon Scores (Medium Creature):|
|Quarterstaff (as 1D6/-)||B||4|
|Table 1-2: Martial Melee Weapon Scores (Medium Creature)|
|Spiked Armor||P||(Ad-Hoc Weight) –2|
|Spiked Shield (Hvy)||B/P||9(W)/14(S)|
| Table 1-3:
Exotic Weapon Scores (Medium Creature)
|Bastard Sword (2H)||S||8|
|Whip||S||2 (Probably Ad-Hoc to –4)|
|Axe (Orc Double)||S||8/7 (Or 15 with one side)|
|Chain (Spiked)||P||12 (Probably Ad-Hoc to +8)|
|Dire Flail||B||5/5 (Or 10 with one side)|
|Gnome Hooked Hammer||B/P||6 (hammer)/10(Pick)|
|Two-Bladed Sword||S||6/6 (Or 12 with one side)|
Ranged Weapons Gain –1 penetration for every range increment beyond their first. Due to the difficulty in properly assigning a formula for ranged weapons I’m going off of the idea of for thrown weapons, longbows, shortbows and slings: Ammo Weight + User’s Strength + Composite Bonus +Masterwork Bonus (+1) + Magic Bonus –Distance (For Longbow add +4 Shortbow +2)(-Size for thrown)(-2 for bludgeoning) Crossbows have a default 10-size-2 for light
| Table 1-4:
Ranged Weapon scores (Medium Creature)
|Crossbow (Heavy Repeating)||10|
|Crossbow (Light Repeating)||8|
And solely because a Katana thread inspired this:
| Table 1-5:
Katana scores (Medium Creature)
| Table 1-6:
Armor Penetration Resistances
|(Found By Taking: [ACBonus-maxDex+(Weight/2)]/3 round down|
 Modifiers For Armor:
- Masterwork grants a +1
- Magic Bonuses grant +=magic bonus
- Mithral armor counts as full weight for Penetration Resistance
- Additional Bonuses: Half Plate and Full Plate can gain "Reinforcement" for +100 GP this adds +2 to the Penetration Resist and can be added up to 2 times. This counts as a variation on masterwork and stacks with that bonus.
- Natural Armor:
For every point of natural armor the creature has +1 penetration resistance starting from -2
Greater Penetration [General]
Prerequisites: STR: 13, Power Attack
Benefit: Gain +1 on weapon Penetration
Penetration Skill [Fighter Bonus]
Prerequisites: STR 13, Weapon Focus in chosen weapon
Benefit: Gain +2 on Penetration attempts with the chosen weapon.
 Penetration and Spells
Touch attacks ignore penetration values
- Area of effect spells have (Spell level)+(casting Attribute Mod) Penetration value
- Ray Spells have 5+(Spell Level)+(double Casting Attribute Mod) Penetration Value
- Targeted Spells have 10+(Spell Level)+(Trippe Casting Attribute Mod) Penetration Value
- Spell Penetration adds +5 to this value and Greater Spell Penetration an additional +2.
- Mage Armor grants a +4 penetration value and replaces the caster's previous armor's bonus
- Shield Grants no bonus
- Other Armor increase Spells grant 3+spell level Penetration bonus
 Last notes
Once again PEACH