Active blocking

Active Blocking
Player characters can actively block by holding the block key (default: left shift). While blocking, a character gains +2 Armor Class, has increased Damage Reduction, and is immune to most special attack and weapon effects. This includes, but is not limited to, Scorpion/Spider Poison, Wraith Constitution Drain, and damage enchantments such as Crippling, Flaming, Wounding, Maladroit, and even Bane. The benefits of blocking apply only to attacks against the character's front 180°. A shield is not required, although shields noticeably increase the amount of extra DR gained.

A blocking character cannot attack with weapons. If he has a shield, he may attack with it instead, using the shield's attack and damage values. This requires no special skill or feat, though the character suffers attack penalties if he is not proficient with that shield, and he loses the shield's bonus to his Armor Class unless he has the Improved Shield Bash feat.

Characters cannot run normally while blocking. They either hop or somersault instead, depending on their Tumble skill. Blocking characters cannot jump at all. Blocking characters can cast spells and activate items, but this cancels the blocking status until the casting finishes.

Active DR Formula
Active DR is the additional Damage Reduction gained while blocking. It stacks with the character's Passive DR.

With Shield:

This formula applies when blocking with a shield against melee attacks. Active DR is halved if blocking ranged attacks.

Active DR = (BAB / 2) + 2 + Shield DR rating + Shield Mastery Feats + Shield Mastery Enhancements

The following feats and enhancements may further increase Active DR while using a shield. They all stack.
 * Shield mastery +3
 * Improved shield mastery +3
 * Dwarven shield mastery +1, 2, or 3 (for levels I, II, and III of the enhancement)

Two-Weapon Fighting:

This formula applies when blocking melee attacks while wielding two weapons. Active DR is divided by 4 if blocking ranged attacks.

Active DR = (BAB / 3) + 2 + Two-weapon Blocking Feat

The following feat may further increase Active DR while wielding two weapons.
 * Two-weapon blocking

Two-Handed Fighting, Single weapon & no shield, or Unarmed:

This formula applies when blocking any attacks while wielding a two-handed weapon, a single weapon but no shield or fighting unarmed.

Active DR = (BAB / 5) + 1

Examples

 * Example 1 - A level 8 fighter with the regular and Improved shield mastery feats, actively blocking with a +4 Heavy Adamantine Shield would have the following DR when using or blocking with shield:
 * Passive DR vs. melee and ranged = DR1/-
 * Active Blocking DR vs. melee = 1 + [(8/2) + 2 + 2 + 4 + 6] = DR19/-
 * Active Blocking DR vs. ranged = 1 + [(8/2) + 2 + 2 + 4 + 6]/2 = DR10/-


 * Example 2 - The same level 8 fighter with two weapons would have the following DR:
 * Passive DR vs. melee and ranged = none
 * Active Blocking DR vs. melee = [(8/3) + 2] = DR4/-
 * Active Blocking DR vs. ranged = [(8/3) + 2]/4 = DR1/-


 * Example 3 - A level 14 barbarian with innate DR5/-, a two-handed weapon (THF), and Stoneskin (DR10/Adamantine) would have the following DR:
 * Passive DR vs. melee and ranged = DR10/Adamantine OR DR5/-For normal attacks he effectively has DR10. For Adamantine attacks he has DR5/-.
 * Active Blocking DR vs. melee and ranged = [10 or 5] + [(14/5) + 1] = DR10/Adamantine OR DR5/- AND DR3/-For normal attacks he effectively has DR13. For Adamantine attacks he has DR8/-.