Template:CalledShot

Just before making an attack roll with a weapon or an unarmed strike, you can make a called shot either by expending 2 stamina points, or by taking disadvantage on the attack roll. You cannot make a called shot if the attack roll would have disadvantage anyway.
     A called shot generally aims for wherever the target is most vulnerable, such as gaps in a warrior's armor, or the exposed eye of a large monster. This kind of called shot maximizes the damage dice rolled on a hit (e.g., treat 1d8 as simply 8), including any extra dice rolled as part of a critical hit or from other sources. Your DM may enable alternate or additional effects for a called shot.