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Your defenses are your ability to protect yourself against various types of attacks, such as goblin swinging a sword at you or a wizard casting fireball. Different defenses will protect you from different attacks. Each of your defense scores follow the following formula:

10 + (half your level) + (armor or shield bonuses if applicable) + (ability modifiers) + (feat, race, untyped, etc bonuses)

There are 4 defenses:

  • Armor Class (AC): Your armor's effectiveness and your ability to dodge or deflect physical blows is measured by your AC. The armor you wear, the type of shield you use (if any), and possibly your Intelligence or Dexterity all contribute to this.
    • If you wear light armor (cloth, leather or hide), add either your Intelligence modifier or Dexterity modifier to your AC (whichever is higher).
    • You do not take a penalty if one modifier is negative but the other isn't. For example, if you have 12 intelligence and 8 dexterity, you gain +1 to your AC from intelligence instead of 0 or -1. If you roll your stats and your intelligence is 8 and your dexterity is 3, then you would only take a -1 to AC because intelligence has the highest modifier.
  • Fortitude is your ability to endure physical stress, poison, intense pain, etc. Your Strength or Constitution modifier (whichever is higher) increases this defense.
  • Reflex measures how well you react to incoming dangers, either dodging out of the way or shielding yourself from the brunt of the attack. Many spells and some physical attacks target your reflex defense. Add the higher of your Dexterity or Intelligence modifiers to this defense (again, you don't take a penalty for a negative modifier if the other modifier is positive). In addition, equipping a shield will add to your Reflex defense.
  • Will is your willpower in fighting against effects that try to affect your body or mind. Many physically and mentally harmful powers target your will, including mind control and domination effects. Add your Wisdom or Charisma modifier to this defense, whichever is higher.

When an attacker makes an attack roll, it must equal or beat the targeted defense to qualify as a hit. Some powers take effect on a miss too, though with limited potency.


Feat Requirement Benefit
Great Fortitude - +2/+3/+4 Fortitude
Lightning Reflexes - +2/+3/+4 Reflex
Iron Will - +2/+3/+4 Will defense
Improved Defenses - +1/+2/+3 to Fortitude, Reflex and Will
Frozen Soul Constitution 13 or Wisdom 13 +1/+2/+3 Will Defense, Resist 5/10/15 cold
Superior Fortitude Strength 15 or Constitution 15 +2/+3/+4 Fortitude defense, Resist 3/6/9 to ongoing damage
Superior Reflexes Dexterity 15 or Intelligence 15 +2/+3/+4 Reflex defense, gain combat advantage against all enemies during first turn of encounter.
Superior Will Wisdom 15 or Charisma 15 +2/+3/+4 Will defense, make saves against Dazed or stunned condition