Miss chance

Several effects each provide a chance (tested by a d100 roll) that a physical attack (melee/ranged) will miss. While each miss chance is actually tested separately, you can calculate a total effective miss chance to help evaluate your squishyness. The following game mechanics grant you a miss chance:
 * Concealment
 * Dodge bonus
 * Incorporeality

For other ways to increase your survivability versus physical attacks, see:
 * Armor class
 * Damage Reduction
 * Physical Resistance Rating
 * Hit points
 * Fortification

In general, trying to increase any one Damage Mitigation factor (eg extreme AC or Hit Points) at the expense of the others is unwise, try to increase all Damage Mitigation factors.

Total Effective Miss Chance
For PC's a common source of Concealment can be the Displacement spell, a Blur effect or blindness inflicted on the target. An Incorporeal effect can come from an item with the Ghostly property or from some Class Enhancements and Epic Destinies.

The formula for calculating the Total Effective Miss chance is: D = (100-Dodge)/100 C = (100-Concealment)/100 I = (100-Incorporeal)/100 ∴ Miss chance % = (1-(D*C*I))*100

This table shows the Total Effective Miss Chance for combinations of Dodge, Concealment & Incorporeal.
 * Dodge
 * in 5% increments up to 25%
 * Concealment
 * Dusk - 10%
 * Blurry, vision obscuring Cloud spells, etc - 20%
 * Lesser Displacement - 25%
 * Displacement, Shadow Walk or Blindness - 50%
 * Incorporeality
 * Ghostly - 10%
 * Shadow Veil - 25%
 * Shadow Form - 25%
 * Shroud of the Wraith - 25%
 * Ghostly Essence - 25%