Resistances

Damage Types and corresponding Resistances correspond to one of the following types:

Physical
Armor provides the most protection against physical damage. This includes most weapons, poison, etc.

Magical
Magic attacks tend to ignore armor. Magical resist encompasses magical damage not covered by specific elemental type.

Air
Most electrical attacks stun their target. This includes natural lightning, static charges, etc.

Water
Cold tends to slow its target. Includes ice, snow, etc.

Fire
Attacks based on heat does damage over time. Includes actual fire, radiant energy (like the sun), etc.

Earth
Attacks based on Strength.

Chaos
Chaotic magic...

External Reference

 * This is extremely old and outdated information only provided for historical purposes: Magic, Combat, and Crafting Skills on the Shroud of the Avatar Forums