AD&D game combat does not use a hit location system to determine where every blow in a battle has landed. Sometimes, however, characters and creatures will find it necessary to aim their blows at an exact point. A fighter may want to smash a vial held in the evil wizard's hand; a thief might attempt to shoot the jeweled eye out of an idol with his crossbow. These are cases where the character is attempting a "called shot."
Called Shots[]
To make a called shot, a player must announce his intention before any initiative dice are rolled. Upon doing so, he suffers a +1 penalty to his initiative (representing the time spent carefully aiming his attack).
When the character does get a chance to act, his attack roll suffers a -4 penalty. If the roll succeeds, the called shot accomplishes what the player wanted; if the roll missed, no damage occurs.
Because the AD&D game uses a generalized system for damage, called shots cannot be used to accomplish certain things. Against a creature, a called shot will only cause the normal amount of damage allowed the weapon. Attempts to blind, cripple, or maim will not succeed. So what can it do?
A called shot can cause a target to drop items or react in some other, more subtle, way. It can penetrate weak points in armor. It also can be used in attempts to knock an object out of a hand, shatter a flask, or otherwise damage items. Called shots can be very useful in activating the trigger of a known trap (if this can be done with a weapon) or in impressing the locals in an archery contest.