Cost: 3, 5, or 8 points per +1 ST

Arm ST is a physical, exotic advantage, described in Basic Set, p. 40.


Douglas ColeEdit

in April 2010

Last August, I suffered a three-level disc herniation at C4/5, C5/6, and C6/7. The upshot of all that was a 30% reduction in the strength of my left arm. If I'm normally ST10 or 11, my left arm was 8 or 9, respectively.


For cost, I'd probably do something like this (and I like complicated formula):

(1-Sqrt(percent of ST remaining in that arm)) percent discount off Arm ST (5/level)

So my case for 70% ST in one arm would be:

sqrt(.7)= 0.82

1-x = 0.18

Round up for the fun of it, and that's 20%. So 20% of Arm ST is 1 CP.

That's probably about right...70% ST in one arm and 100% in my dominant arm is a quirk level impediment.

further talkEdit

September 2010

sir pudding " I'd just call -1 Arm ST a Minor Handicap Quirk" .. "It should be [-1] for anything between -1 to -1/4"

Gurps_fan created this table:

[B]Arm ST Both arms One arm[/B]
100% of overall ST† 0 point 0 point
90% of overall ST -1 point 0 point
80% of overall ST -2 points -1 point
70% of overall ST -3 points -1 point
60% of overall ST -4 points -2 points
50% of overall ST† -5 points -2 points
45% of overall ST -6 points -3 points
40% of overall ST -7 points -3 points
35% of overall ST -8 points -4 points
30% of overall ST -9 points -4 points
25% of overall ST† -10 points -5 points
†: RAW value

and subsequently a writeup...

New Quirk: Weak Arm†

-1 point

You have weaker arm(s) in comparison with your overall body ST. Choose one of the following two specialties:

Weak Arm (Both): Both of your two arms have effective ST of the lower of your ST-1 or 90% of your ST.

Weak Arm (One): One of your two arms (your choice) has effective ST of the lower of your ST-2 or 80% of your ST.

Ejidoth followed:

If/when a player asks for weaker Arm ST, I use the square root of (Arm ST / Full ST), minus one, convert that to a percentage, and round toward zero to a multiple of 5%. Technically you don't need to round, but it looks more official if you do.

Ze'Manel Cunha proposed using the NFM modifier:

I use the NFM modifier for body ST which isn't used by arms.

Which isn't really correct, since NFM guys can use arms, they just lack HANDS, so they can still punch and stuff for high damage.

Pudding pointed out a balance problem:

Having ST 20 [100] and two ST 10 arms [-5] is a net [195]. ST 10 [0] and ST +10 (NFM-40%) [160] is a net [160]. Your method gives much bigger point breaks and it increases with ST.

ZMC countered:

As it should, you don't have any extra HP on those arms, and you can't use weapons with those arms.


Arm ST doesn't effect HP at all (Basic page 40).

It really should though!

Kuroshima objection:

The thing with applying NFM to part of your ST is fairier, points-wise. Having your base two arms be weak is definitively worth more than -5 points. Take a centaur, for example. Consider:

a) Weak arms: ST 20 [100] + two weak arms [-5]. Total 95

b) ST +10 (NFM, -40%) [60]. Total 60

c) Striking ST +10 (Kicks only, -60%) [20]+HP +10 [20]+Lifting ST +10 (Does not affect arm ST, -10%*) [27]. Total 67

  • Eyeballed. Most of the usefulness of lifting ST comes from increased encumbrance thresholds, but you lose grappling utility and all arm related feats.

Now tell me there's a functional difference between a and c. b is slightly worse than c, because it would reduce crippling thresholds for the upper body, so it's fair that it costs less points.

See AlsoEdit