Damage calculation

Damage Types
There are several different types of damage in Guild Wars.
 * Elemental damage
 * Fire damage
 * Cold damage
 * Lightning damage
 * Earth damage
 * Physical damage
 * Blunt damage
 * Piercing damage
 * Slashing damage
 * Special damage:
 * Holy damage and Light damage
 * Chaos damage
 * Shadow damage and Dark damage

Damage Calculation

 * Does its damage type get changed?
 * Does it hit or get Evaded?
 * Does its get modified in amount? (depending on its type and level)?
 * does it ignore Armor?
 * Calculate resulting Damage with Armor and armor penetration:

[Source]
 * Base Damage is just a simple factor, two weak attacks always equal one attack that is twice as strong.
 * Weaker Armor (depending on damage type) is slightly exponentially worse than stronger armor.
 * Higher armor penetration makes this slightly more exponential.

Damage Groups
There are also two damage groups in Guild Wars
 * Spike Damage
 * Damage-Over-Time