One of the better ways to avoid taking damage is to hide behind something or avoid being spotted. Each source of cover or concealment is assigned a rating from 1 to 5, with 1 representing light obstruction and 5 representing nearly complete protection.

When an attack is made against a target with cover or concealment, the attacker rolls 2d10 as normal. If either die shows a value equal to or less than the cover rating, the attack automatically misses, regardless of the total roll. This reflects the chance that a strike or projectile is blocked or obscured by the environment, and it is integrated directly into the attack roll.

The same chance to miss also applies to any skill requiring direct observation of the target. For example, attempting a Perception check against a creature in mist, or using Knowledge to Translate Writing through a peephole, may incur a concealment chance.

The following table gives some sample levels of cover and concealment.