Dodging
The Dodge skill is one of three parts of the Evade/Block/Parry system of GemStone IV, therefore being one of three skills that will increase a character's Defensive Strength.
Defensive Strength
Dodge is the least stance dependant of the three skills, only having a 25% reduction in DS when in an offensive stance. The formula is as follows:
Dodge Ranks + (Agility Bonus / 2) + (Intuition Bonus / 4) = Base Dodge
While:
Stance Modifier = 0.75 + (Stance / 4)
Shield Penalty is 0.8 with a small shield, 0.7 with a medium shield, 0.6 for a large shield, and 0.5 for a tower shield. Armor Hinderance is half the Action Penalty subtracted in percentage, so metal breastplate (Action Penalty of -20) would be -10% or 0.9.
The resulting formula:
Base Dodge X Stance Modifier X Shield Penalty X Armor Hinderance = Dodge DS
Note: There is a 50% bonus to this DS if the attacker is using a ranged weapon.
Evading
Dodge skill also aids a character to avoid an attack entirely. The higher the character trains in dodge, the higher his changes of dodging the attack. A character singled in Dodge has appoximately a 5% chance of dodging an attack outright. A character double trained in Dodge has a 10% chance, and tripled has a 15%. The exact values also depend on stance, Agility bonuses, Intuition bonuses, encumbrance, armor hindrance, and spells such as Mass Blur. There is no available formula to determine the exact chance that an attack will be evaded, but character level plays into this greatly. Also, ranged weapons and bolts are harder to dodge than a melee attack, even though there's a DS bonus against such attacks (See the Defensive Strength section above).