Homebrew Parrying System

[Tower]

I always found the lack of a parrying system in D&D strange, especially since Neverwinter Nights 2 had one, so here's an attempt at a homebrew system for it

Parry (Skill)
After putting skill points in the Parry skill your character gains the ability to attempt a parry with a melee weapon
This parry attempt uses one attack to temporarily raise your AC by one third of the attack bonus plus 1+1 for every 4 levels of parry skill until his next round, but can't use it to attack
Each successful parry reduces the AC bonus by 2, as the parries become harder to maintain

A level 6 fighter with 9 ranks of Parry could use his +6 attack to gain a +5 bonus to AC, or his +1 attack to gain a +3 bonus to AC until his next round.

A level 12 fighter with 10 ranks of Parry could use his +12 attack to gain a +7 bonus to AC, or his +7 attack to gain a +5 bonus to AC, or his +2 attack to gain a +3 bonus to AC until his next round.

A level 5 cleric with 4 ranks of Parry could use his +3 attack to gain a +3 bonus to AC for one round, but could not attack until his next round.

[Tower]

Parry Related Feats

Improved Parry (Feat)
Prerequisites 1 rank of Parry
Gaining this feat adds +2 to your AC bonus when using a parry

Superior Parry (Feat)
Prerequisites 8 ranks of Parry, Improved Parry
Gaining this feat adds +4 to your AC bonus when using a parry, this replaces the +2 bonus of Improved Parry

Parry Recovery (Feat)
Prerequisites 4 ranks of Parry, Improved Parry
Gaining this feat reduces the penalty of multiple parries to -1 per parry

Lightning Parry (Feat)
Prerequisites 8 ranks of Parry, Parry Recovery
Gaining this feat reduces the penalty of multiple parries to 0 per parry

Counter Attack (Feat)
Prerequisites 4 ranks of Parry, Improved Parry
Gaining this feat allows an attack of opportunity when an attack is successfully parried, presuming the character has an attack of opportunity left

Improved Counter Attack (Feat)
Prerequisites 10 ranks of Parry, Counter Attack, Combat Reflexes
Gaining this feat allows an attack of opportunity for each attack that is successfully parried, presuming the character has enough attacks of opportunity left to attack

Deflective Parry (Feat)
Prerequisites 6 ranks of Parry, Improved Parry
Gaining this feat means that on a sucessful parry, the weapon is sufficiently deflected to make recovering from the attack difficult. This in game terms mean a -2 modifer to Attack bonus and Parry AC for the opponents next turn

Improved Deflective Parry (Feat)
Prerequisites 14 ranks of Parry, Deflective Parry
Gaining this feat means that on a sucessful parry, the weapon is sufficiently deflected to leave the opponent flat-footed, allowing for others to make Attacks of Opportunity

[Tower]

Two Weapon Parrying Feats

Two Weapon Parry
Prerequisites 6 ranks of Parry, Two Weapon Defense
Gaining this feat allows the character to use an attack from each hand to parry, adding both AC Bonuses together

Off-Hand Parry
Prerequisites 12 ranks of Parry, Improved Two Weapon Fighting
Gaining this feat allows the character to use all attacks from his off-hand to parry, adding all AC Bonuses together.

[Matthew]

Here's a link to all previous attempts to create an Active Defence:

Z-Axis’s Combat Action and Feat (http://www.giantitp.com/forums/showthread.php?p=3020404#post3020404)
Skjaldbakka's Parrying System (http://www.giantitp.com/forums/showthread.php?t=48609)
Talanic & Erk's Interception System (http://www.giantitp.com/forums/showthread.php?t=44108)
Tough Tonka's D20 Parrying System (http://www.giantitp.com/forums/showthread.php?t=38214)
Elliott20's Parrying System (http://www.giantitp.com/forums/showthread.php?t=36139)
Magic8Ball's Parrying Feats (http://www.giantitp.com/forums/showthread.php?t=34053)
Munchy's Parrying Fighter Feats (http://www.giantitp.com/forums/showthread.php?t=23175&page=2)
Senir's Parry Skill (http://www.giantitp.com/forums/showthread.php?t=25404)
Matthew's Active Defence (http://www.giantitp.com/forums/showthread.php?t=22979&page=2)

Your idea is interesting in that it deviates from the standard method; it reminds me of the Advanced Dungeons & Dragons PHB Parry Optional Rule. Seems kind of redundant when we have Improved Combat Expertise, but still interesting.

Which Attacks are you sacrificing? Lowest or Highest or 'your choice'?

[Tower]

PC's choice.
Thought it better represented using a weapon to focus on blocking attacks or attacking while trying to parry.
Plus you could change round to round if you are losing or winning.

[Tower]

Parry is a Class Skill for
Barbarian, Bards, Clerics, Fighter, Monks, Paladins, Rangers, Rogues.
Other Martial/Rogue focused character should have it as a class skill.

Unarmed Parries are possible, if the character has Improved Unarmed Strike, but there is a -2 modifier to the Parry Bonus as they are blocking with their bodies
Gauntlets, etc. reduce this to -1, as some protection but still more likely to get injured

Weapon Focuses and other bonus to Attack rolls, except Stat based modifers, are added to BAB for the Parry AC bonus.

Flat-footedness does not affect AC bonus from parry, but any effect that would otherwise interfere with movement or skill usage, such immobisilation, confusion etc. stop it from being usuable.

Slow and Haste give a respective -2, +2 bonus to Parry AC
Sneak Attacks can be parried only if rogues/attackers can be seen
Flankers affect bonus via Attack penalty.

Concealed/Blurred/Displaced Attackers nullify parry bonus on miss chance,
so a 20% miss chance would mean a 20% chance of bypassing Parry AC

Incorpereal Attacks can be parried if character has Ghost Touch Weapons