The Parrying and Bushido skills are checked during combat to determine whether an attack can be fully blocked. Melee and archery attacks can be fully parried if the defender is using a Shield or Melee weapon.
On a successful parry, the attacker will miss completely.
If a special move is parried it will not drain mana from the special move user.
Note that if you are using a shield, the Bushido skill will actually lessen your chance to block an attack.
The formula below includes a dexterity modifier if dexterity is less than 80. In simple terms this means that you require 80 dexterity to have maximum parry chance.
Training
When choosing opponents to train against quantity is preferable to quality, ie better gains will be had by fighting numerous low to mid level mobs than one high level mob. If using a shield, a buckler is preferable to a heater shield.
FORMULA:
Blocking with a shield:
% Chance = (Parrying – Bushido) / 4 (If less than 0, the chance is 0)
(Add 5% if Parrying or Bushido skill is 100 or above)
Blocking with a 1-handed weapon (without a shield):
New = (Parrying * 10) * (Bushido * 10) / 48000 (Add 5% if Parrying or Bushido skill is 100 or above)
Legacy = (Parrying * 10) / 80 (Add 5% if Parrying skill if 100 or above)
% Chance = Whichever is highest of the New and the Legacy formula.
Blocking with a 2-handed weapon:
New = (Parrying * 10) * (Bushido * 10) / 41140 (Add 5% if Parrying or Bushido skill is 100 or above)
Legacy = (Parrying * 10) / 80 (Add 5% if Parrying skill if 100 or above)
% Chance = Whichever is highest of the New and the Legacy formula.
Dexterity Modifier if dex is less than 80: (80 – Dexterity) / 100 (If Dexterity is higher than 80, the modifier is 0)
Final % Chance of blocking = Base Chance * (1 – Dexterity Modifier)