Cover

Cover allows creature in LOR to avoid damage more easily. There are three types of cover which provide the following benefits

Against melee hit rolls, however, you reduce the penalty by half(round down).

Light Cover 

-1 to incoming hit roll

Standard Cover

-2 to hit roll against you and +2 to reflex slaves

Heavy Cover

 -4 to hit roll against you and +4 to reflex slaves

High Ground

High Ground is considered as standard cover and when on hign ground, attacks ignore cover and gain advantage on prone targets