In many games that I have played, there is always a circumstance where a player would like to take a shot at an enemy. Within the Pathfinder RPG, and even DnD, there are no substantial rules or graphics for making a called shot against an enemy and what the results are. So my playgroup and I have come up with a simple system that is for both the player and the DM. (Note that this rule can have devastating effects on your monsters, so use it with caution.)
So to begin with, you need to establish what the player is trying to hit that way you can decide the difficulty of the attack. The called shot should be increased based on the size of the location being attacked, but before doing so, you need to understand the difference between what is or is not a called shot. To take a called shot first, the player must specify the location of the enemy they wish to attack. (Declaring that you want to attack the left flank of a large creature like a dragon is not a called shot, that’s called an attack.) The area should be a very specific location, such as between the ribs directly under the enemy’s armpit. / creature, or the eye would be an acceptable statement.
Now you, as a DM, must decide how difficult it is to get to that specific location based on a few simple questions. How big is the attacked area. To help, here is a simple table based on size location.
Good: (this is 6 inches or less) +8 added to the base Armor class to hit the area.
Diminutive: (7 inches to 1 foot) +4 added to base armor class to hit area
Tiny: (1 ft 1 inch at 2-1 / 2 ft) +2 added to base armor class to hit area
Small **: (3ft to 5ft) +1 added to base armor class to hit the area
** (These areas should only be incorporated or approved by the DM if the creature is huge or larger)
Now that you have determined the difficulty of hitting the area, you need to decide if there are any additional factors to add to the difficulty before making the attack, such as is the target area armored? if so, the armor-tearing penalties should apply as normal. (An alternative option is to add an additional AC bonus to the target area based on the material the armor is made of.)
Padding: + 1 / Leather / Leather / Studs: + 2 / Metal: + 3 **
** (Special metals like adamantine should apply their damage reduction rating if the area is hit).
Now the attack is made against the target location. As a DM, you must determine if the called shot will be a fatal blow if the attack is made. If the attack has the potential to kill the target, if successful, I have devised a rule to determine if the target survives the hit whether or not it withers. If the attack is successful, the target must make a DC 10 fortitude save + damage dealt or die. (As I said above, this can be used to take down monsters in single hits and forces the DM to execute his villains carefully, but remember that DM monsters can take aim too, and not all shots are fatal.)
Alright, let me give you an example so this muddy water can clear up a bit.
“Crow the barbarian has engaged Thwak, the orc warlord, in single combat! At the start of the fight, Thwak landed some devastating blows at Crow and the outcome for our hero looks grim. Crow decides that has to win this fight in one fell swoop or be killed by the monstrous Orc. So Raven declares that he wants to take a shot with his great sword and drive it into the mighty Orc’s throat. Thwak has a starting armor class of 20, but Hitting him in the throat is much more difficult than just hitting him directly and the throat is a fine target that increases Thwaks’ armor class by an additional +8, making his adjusted AC 28. Fortunately for Crow, the area does not is armored, so no additional adjustments are necessary to hit the area. His attack. Raven has +14 to hit with his enchanted Great Sword and rolls a 16. (14 + 16 = 30) Raven lands a powerful indentation on the gargant a from Thwak. (Now obviously a great sword at the throat has the potential to be fatal, so this attack will force a save fortress.) Raven’s damage when wielding his great sword is 2d6 + 8, so he deals damage normally as you would with any attack. Raven deals 14 damage to Thwak’s throat and forces a fortress save difficulty 10 + damage dealt, so Thwak needs to roll his fortress save and reach a total of 24 or more to survive the attack. Thwak has a +10 to his fortitude save, but he only rolls a 4 to his save, failing the test and his head is taken off when Raven takes his head off his shoulders. “
This rule may take some time to become familiar with, but it has the potential to increase the flavor of your combat scenes by forcing your playgroup to do more than just roll the dice and tell you the damage. This rule can be used by any attack that requires an attack roll, even touch / ranged touch spells!
Enjoy.