Depending on the situation, a character may gain bonuses or suffer penalties due to cover. The DM judges what bonuses and penalties apply.
Cover provides a bonus to a character's AC. The more cover a character has, the bigger the bonus.
|* Half damage if save is failed; no damage if successful.|
An attacker can't execute an attack of opportunity against a character with one-half or better cover.
If a character is using a reach weapon, another character standing between the attacker and the target provides cover to the target. Generally, if both of the other characters are the same size, the one furthest from the attacker has one-half cover (+4 AC).
Cover is assessed in subjective measurements of how much protection it offers a character. The DM determines the value of cover.
Add this bonus to Reflex saves against attacks that affect an area. For nine-tenths cover, a character also effectively has improved evasion. These bonuses, however, only apply to attacks that originate or spread out from a point on the other side of the cover.
If it ever becomes important to know whether the cover was actually struck by an incoming attack that misses the intended target, the DM should determine if the attack roll would have hit the protected target without the cover. If the attack roll falls within a range low enough to miss the target with cover but high enough to strike the target if there had been no cover, the object used for cover was struck. This can be particularly important to know in cases where a character uses another character as cover. In such a case, if the cover is struck and the attack roll exceeds the AC of the covering character, the covering character takes the damage intended for the target.
If the covering character has a Dexterity bonus to AC or a dodge bonus, and this bonus keeps the covering character from being hit, then the original target is hit instead. The covering character has dodged out of the way and didn't provide cover after all. A covering character can choose not to apply his Dexterity bonus to AC and/or his dodge bonus, if his intent is to try to take the damage in order to keep the covered character from being hit.
Concealment includes all circumstances where nothing physically blocks a blow or shot but where something interferes with an attacker's accuracy. Concealment is subjectively measured as to how well concealed the defender is. Concealment always depends on the point of view of the attacker.
Concealment gives the subject of a successful attack a chance that the attacker missed because of the concealment. If the attacker hits, the defender must make a miss chance percentile roll to avoid being struck. When multiple concealment conditions apply to a defender, use the one that would produce the highest miss chance. Do not add the miss chances together.
|One-Quarter||Light fog; moderate darkness; light foliage||10%|
|One-Half||Dense fog at 5ft.||20%|
|Nine-tenths||Near total darkness||40%|
|Total||Attacker blind; target invisible; total darkness; dense fog at 10 ft.||50%|