No Man's Land
If a target is in melee with a creature of the same size or larger, it gets 1/2 cover (+2AC) from ranged attacks by opponents. (It also gets +2 vs Area of Effects.. see magic)
If an attack would hit but for this bonus, then the attack hits one of the creatures providing cover provided it would hit th Armor Class of the cover. If it would not, the attack is just a clean miss.