Following the trend of providing a look into how I handle hit points, attacks, and general bodily-harm, we now turn to the tactics of 'called shots', or as I prefer, 'disruptive force'.
In systems, where they are utilized, the 'called shot', "aimed shot" or other, is the focused effort of a character to maximize and severely hamper his opponent through a high-risk, high-reward method of taking a full-round action, or simply a -4 to hit in combat, or other similar variation. If successful, results can be anywhere from boosted, doubled or tripled damage that is basically an alternative to rolling a critical hit. The benefit of a called shot however, is that the caller can specify which area of his opponent's body he chooses to strike. Which can have dire consequences to encephalized beings when head-shots are landed, or chins are smashed on ball-chineans.
Now what does that mean for my system with its version of hit points? Dirty fighting: elbows, groin shots, eye-jabs, and sprained or bruised limbs. Similar to Third Edition and newer's -4 in combat for unarmed strikes, the character between his many thrusts per each six-second round takes the effort to land an unpleasant blow against his foe. Damage is often doubled of normal attack/weapon damage for the attacker, as it is assumed s/he would use their preferred method of reducing his foe's abilities, hastening the opportunity for a killing blow. It may be smashing the haft of a pole-arm, decking with a sword pommel, head-butts, knees to the kidneys, and other injuries that are more painful than truly harmful.
As mentioned before, criticals are rolled for on critical charts that I keep stuck to the DM screen. One of the table results is full normal attack/weapon damage directly to a character's CON score. When this result affects monsters, the attack instead outright kills anything with a HD equal to half or less of the attack's damage. Everything else is generally larger monsters under the jurisdiction of hit points as physical damage threshold, and will instead suffer a number of six-sided dice in damage equal to the maximized attack (with strength modifiers). So a weapon that deals 1-8 damage in the hands of a barbarian that also deals 3 additional damage based on his strength, will outright kill anything with 5 HD or less, or will deal 11-66 damage to 6 HD+ beasts. This is one of (usually) 12 results on the criticals table.