- # Cover - Half cover: +2 to AC - Three quarters cover: +5 to AC - Total cover: cannot be targeted - To determine whether a target has cover against an attack or other effect on a grid, choose a corner of the attacker’s space or the point of origin of an area of effect. Then trace imaginary lines from that corner to every corner of any one square the target occupies. If one or two of those lines are blocked by an obstacle (including another creature), the target has half cover. If three or four of those lines are blocked but the attack can still reach the target (such as when the target is behind an arrow slit), the target has three-quarters cover. - On hexes, use the same procedure as a grid, drawing lines between the corners of the hexagons. The target has half cover if up to three lines are blocked by an obstacle, and three-quarters cover if four or more lines are blocked but the attack can still reach the target. - # Concealment - Concealment is different from cover in that concealment just means the target cannot be seen. Targets that can't be seen can still be targeted, but at a disadvantage. - Player tells DM where they're targeting and rolls for the attack at a disadvantage. - If they hit and the creature was not in that spot, they miss. - If they hit and the creature was in that spot, they hit. - If they miss... well, they miss anyway.