Rules Bit (GURPS): Duck!

Intro: “Not the face!”

Ducking your head beneath a blow, or pulling a hand out of harm’s way, is much easier than shifting your whole body in a split-second. It’s simple to game this in GURPS.

The rule

Allow a +1 bonus on Dodge when the target is a mobile extremity: head, arm, hand, wing, tail, antenna, and so on.

That’s it.

Definition of mobile extremity

The target part should be able to move reasonably freely and should have a -2 or greater TH mod for location. The body or vitals don’t receive the bonus, nor do legs or feet supporting the body. (A flying bird’s dangling legs would be a different matter; they’re mobile extremities in the same way an arm or wing is.) A human head gets the bonus; a crab’s head (no neck!) would not.

The defense bonus helps safeguard mobile targets, which are particularly vulnerable to attack by virtue of lower HP, lighter armor, or (in the case of the head) vital importance. It’s realistic, too; watch how much more quickly a boxer can pull his head back from a punch than he can move his whole body.

Variants and options


Allow the mobile extremity bonus for legs or feet supporting the body, on a successful Jumping roll. (Or, for another take on this, use the Acrobatic Dodge rule, but let Jumping replace Acrobatics if the target is the legs. Make that Jumping +2 if the target is the feet.) That’s the classic “jump over the sword” move for swashbucklers atop tables!

No-encumbrance clause

If the defender takes a Dodge penalty for encumbrance or any other loss of overall mobility, halve the penalty (round down) for body parts that receive the mobile extremity bonus.

Example: Extra-Heavy encumbrance leaves you with -4 on Dodge when an attack targets your body. But a Dodge to move your head or arm out of the way of danger suffers only a -2, and gains the +1 for a mobile extremity (for a net -1).

Vary modifiers as appropriate. An adventurer with feet stuck in quicksand might take a -2 penalty on overall (i.e., torso) Dodge and half that for the arms and head (which also enjoy the mobile extremity bonus), but an overall -4 for his (fairly immobilized) legs. (His feet, meanwhile, shouldn’t be able to dodge at all, though they may be safe from attack by virtue of being submerged in muck. But whatever the target, don’t forget that retreat isn’t an option for this fellow!)

Extreme mobile extremities

Optionally add another +1 Dodge bonus for extreme mobile extremities: hands (not arms), feet (not legs), moveable antennae (not head), and so on. As a rule of thumb, if it’s on the end of a mobile extremity and has a -4 or worse TH modifier for location, it gets the extra bonus. (A human head doesn’t count, but a small head on a long neck might.)


Add another +1 Dodge bonus for the face (not entire head) or parts of the face. This is not a mobile extremity bonus; it’s a bonus for the natural flinch reflex.

More specifically, the target location must have eyes and the attack must come from within those eyes’ field of vision. For weird non-humans, you may need to replace “face” with body, tentacles, or whatever parts are studded with eyes!

If your game wrestles with high-skill characters who are too fond of combat-ending eye shots, this option can help rein them in.

Designer’s notes

This rule expands a bit upon “Dodge basics” from GULLIVER LITE.

Wrapping up

There’s not much to this one. Go forth and duck, bob, and slip your way to safety.


  • Stupid Jedi

    Hey T-Bone, would this work better as a Technique rather than an optional rule?

    Bobbing & Weaving (A)

    Defaults: Dodge

    Prerequisite: Boxing, Brawling, or Karate; cannot exceed Dodge+1

    Use Bobbing and Weaving for attacks that target the head, arm, or hand.

    • tbone

      Hi there. The article’s AD bonus for appendages is intentionally generic, applying regardless of skill or lack thereof. It’s a simple recognition that an appendage can move more quickly than an entire creature, and would always apply.

      But how about a separate bonus to Dodge for some appendages to represent trained defensive moves? If it makes sense and plays well, then sure! Your suggestion works, though I’d change it to Hard, as Dodge is such a valuable ability.

      If the cost still seems too cheap, I would change the mechanics so the technique doesn’t add directly to Dodge, but instead adds to DX for the purpose of computing Dodge (again, only for head and arms/hands). The max would be DX +4, which computes to +1 Dodge. (Fighters with rounded-down fractional Dodge can achieve +1 Dodge with fewer levels of the Technique.)

      How does that sound?

  • Stupid Jedi

    I’m personally against Hard techniques (the extra point is like having to buy a perk just to learn the technique), but that’s my own bias. I guess from my personal experience (5 years of Karate and I’m a HUGE martials arts fan), people naturally don’t duck, bob, or weave well unless they’ve had some training or experience. Hence, the technique. You’re example of the boxer is perfect, but boxers train extensively on bobbing and weaving. If the training didn’t matter, why do it? Or, are they just learning Enhanced Dodge?

    • tbone

      I agree, boxers train extensively in dodging those head blows, and that should be reflected in the skill. And it was… until 4e. The special Dodge bonus that Boxing used to confer vs punches and other thrusts in 3e is now the same improved Retreat bonus against any attack that Karate, Judo, and fencing skills all enjoy.

      So that arguably makes your suggested Technique, in whatever form works best, a necessity if boxers are to have a special bobbing and ducking ability!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.