Melee Academy: Best Routes to Knockdown

What are the best ways to inflict Knockdown rolls on a foe in GURPS via injury? Information from Basic Set, p. 399-400, for GURPS, and Exploits, p. 60, for DFRPG.

If you need to render a foe stunned and knocked down, or unconscious, in a blow, here are your targets, from the best, to the good options, to the rest. All of these are negatively impacted by Injury Tolerance that affects the area - Unliving, Homogenous, and the various No (location) IT variants all make some or all less effective. Be careful. This guide assumes a human-like target with no special immunities.

Best Options

Eye - Major wounds are easier because of a x4 injury multiplier. Unmodified knockdown roll on any injury; -10 (!) on a major wound. Very hard to target (-10) and only certain weapons can injury the brain to get that multiplier.

Skull - Injury multiplier is high (x4). Unmodified knockdown roll on any injury; -10 (!) on a major wound. Hard to target (-7), comes with native DR 2 and is often armored as well.

Good Options

Face - Unmodified knockdown roll on any injury that causes shock; -5 on a major wound. Hard to target (-5) but is less often armored well.

Vitals - Unmodified knockdown roll on any injury that causes shock; -5 on a major wound. Moderate to target (-3) but limited attack options; armored with Torso armor.

Groin - Humanoid males only. Unmodified knockdown roll on any injury that causes shock; -5 on a major wound. Moderate to target (-3), usually armored with Torso armor.

Other Options

The "Other" options all require a Major Wound to inflict a Knockdown roll, but do not provide improved injury multipliers (or reduce injury) or penalties to the roll.

Neck - Major wounds are easier as most attack forms have an improved injury multiplier. Only a major wound, no penalties to Knockdown roll. Hard to target (-5), covered with Torso armor.

Torso - Only a major wound, no penalties to Knockdown roll.

Arm, Leg, Hand, Foot - These can cause knockdown if crippled - the only way to inflict a Major Wound on a limb or extremity is also to cripple it. Reduced multipliers for impaling attacks.



So your best choices? Hit the eye, skull, face, or vitals. You have an increased chance of putting a foe down, lower thresholds to cause major wounds, and penalties on said rolls.
Finally, don't forget that High Pain Threshold and Low Pain Threshold modify knockdown rolls as well. And failure by 5 is a knockout, so any penalties you can stack on - pretty much only the ones above - are critical! It's hard to knock a foe out or kill them in GURPS, so do what you need to do to stack the rolls against the target with your choice of hit locations.