[Basic] Advantage of the Week: Arm DX and High Manual Dexterity

[Otaku]

Last Week: Appearance Levels
Next Week: Arm ST; Lifting ST; Striking ST

This week is a bit different than I originally planned; last minute decision to group together what I believe are two similar Advantages: Arm DX and High Manual Dexterity. Initially I planned on covering Arm ST but for now, that appears to be next week's subject.

In GURPS, if it can manipulate it is an "arm" (even if it also functions as a leg, a tail, etc.) a per p. B53 under Extra Arms and p. B54 under Extra Legs. Arm DX (p. B40) represents when such a limb is functionally more coordinated than the underlying DX of the main body, and is a Physical, Exotic Advantage. This is meant for tasks that don't rely (at least to the level of system resolution) on anything but your arms; if a task requires multiple arms that don't have the same DX, the rules state that you use the lowest DX among the limbs involved.

There are two important things it does not affect

• Basic Speed
• Combat skills

Fortunately the GURPS 4th Edition FAQ actually has an entry to clarify where the bonus actually comes in handy:

Originally Posted by GURPS 4th Edition FAQ

3.2.6 What is Arm DX good for?

Escape, Filch, Knot-Tying, Leatherworking, Pickpocket, Sewing, Sleight of Hand, many Sports, Typing, etc., as well as any DX-based roll to use the arms with another skill.

Arm DX costs 12 points per +1 for a single arm, +16 for two arms, and if you want to boost three or more arms, you simply have to modify your overall DX. If you bought your base level of DX with the No Fine Manipulators Limitation, it must be applied to Arm DX as well.

High Manual Dexterity (p. B59) is a Physical Advantage that represents improved fine motor skills and costs 5 points per level, with a four level cap for mundane humans. Note: RAW doesn't state that this can be exceeded by those with access to Exotic traits; I am just assuming that like similar restrictions this can be waved with GM permission for things like amazingly coordinated Supers, aliens, etc.

Each level of High Manual Dexterity provides a +1 to DX for tasks that require a decliate touch, such as all DX based rolls against

• Artist
• Jeweler
• Knot-Tying
• Leatherworking
• Lockpicking
• Pickpocket
• Sewing
• Sleight of Hand
• Surgery

plus any DX-based rolls to do "fine" work with Machinist or Mechanic, the book's example of "fine" being clockwork. Skills that normally are based on IQ but are being used with a DX-based roll (some of which are part of that list) get the bonus unless we are dealing with large scale work, but if it isn't an IQ-based roll, there is no bonus.

Arm DX seems to be an expanded version of High Manual Dexterity: barring extenuating circumstances the manipulators on those arms will be similarly more dexterous than the main body as is the rest of the limb. I actually am a bit confused by the specifics of these two traits, but for the sake of clarity I'll hold off on asking my questions until later in the conversation.

So how have these traits served you, or those you have gamed with? Do they seem under, over or appropriately priced? For those that have used them, what traits do you often combine with them? Are there any unusual concepts you've used these to help model?

[sir_pudding]

I've used High Manual Dexerity on racial templates, as well as seen them on DF thieves. I don't think I've ever used (or seen) Arm DX in play.

[simply Nathan]

I think Arm DX is way too expensive for what it does. If it included combat skills it'd still be a questionable buy to take a level of Arm DX (two arms) over a level of overall DX and get bonuses to Acrobatics and some Basic Speed under the current pricing.

Leave its effects alone and cut the prices in half and...maybe. I still probably wouldn't put it on any characters.

[vicky_molokh]

When time comes to Arm ST, better group it together with Striking and Lifting ST, since they cover related topics.

Now, as for Arm DX: I agree that it's too expensive for what it does. I haven't seen it ever used, I think.

High Manual DX I took once, playing a doctor. The GM was nasty and demanded all surgery rolls to be against the lower of IQ- and DX-based Surgery; this was 3e with heavy house-rulings. Before anyone starts talking about how lower-of-two rolls are not recommended, suffice it to say that it was the single GM I more-or-less hate, and consider totally unsuitable for GMing or playing.

Also, a doctor PC in my campaign has one or two levels of High Manual DX. It came up maybe a couple of times, and I feel that the way medical work is made, I can't make it very useful without nerfing Surgery across the board or introducing buggy houserules to the way attributes work.

Oh, there's also a scientist with HMDX in that campaign. Her munchkin friend tried to argue for using this increased DX for Piloting and/or Gunner, since 'it is manual DX of handling a joystick'. Which is of course not allowed if you at least semi-carefully read the description of HMDX.

[Not another shrubbery]

I'm pretty sure that Arm DX isn't supposed to be a bargain. But it does suffer in comparison to a hypothetical Talent that covered the same skills.

[Flyndaran]

Originally Posted by Not another shrubbery

I'm pretty sure that Arm DX isn't supposed to be a bargain. But it does suffer in comparison to a hypothetical Talent that covered the same skills.

16 points for something that's worse in every respect than 15 points of Dexterity without movement is not just no bargain.

[Culture20]

Originally Posted by vicky_molokh

Her munchkin friend tried to argue for using this increased DX for Piloting and/or Gunner, since 'it is manual DX of handling a joystick'. Which is of course not allowed if you at least semi-carefully read the description of HMDX.

Though not RAW, Arm DX should apply. Arm DX should also apply while using a firearm while prone as the rest of the body's DX is no longer relevant (resting on the ground). To see why it should not apply to combat skills in general: imagine an archer with overall DX of 1, and Arm DX of 20. No matter how dexterous the arms, the rest of the person's body is going to be jerking around spasmodically, affecting the arms greatly. I believe that should also make any sports an unlikely use of Arm DX. Any argument convincing enough to allow use of Arm DX with archery as a sport, throwing as a sport, or swinging a bat/club as a sport should be convincing enough to allow similar combat skills.

[vicky_molokh]

Originally Posted by Culture20

Though not RAW, Arm DX should apply. Arm DX should also apply while using a firearm while prone as the rest of the body's DX is no longer relevant (resting on the ground). To see why it should not apply to combat skills in general: imagine an archer with overall DX of 1, and Arm DX of 20. No matter how dexterous the arms, the rest of the person's body is going to be jerking around spasmodically, affecting the arms greatly. I believe that should also make any sports an unlikely use of Arm DX. Any argument convincing enough to allow use of Arm DX with archery as a sport, throwing as a sport, or swinging a bat/club as a sport should be convincing enough to allow similar combat skills.

Originally Posted by B40

Combat
skills rely on bodily DX, and do not
benefit from this DX at all.

^ This, which people doing archery, airsoft and assorted mêlée fighting seem to say is true. AFAIK shooting, even prone, involves controlling not just the arms, but also the head, lungs etc. (which is why there's so much attention to breathing).

[Flyndaran]

Originally Posted by vicky_molokh

^ This, which people doing archery, airsoft and assorted mêlée fighting seem to say is true. AFAIK shooting, even prone, involves controlling not just the arms, but also the head, lungs etc. (which is why there's so much attention to breathing).

Every action involves the whole body if you want to go down the pedantic road though.
For arm dexterity to have meaning at all, it should involve actions that use the arms primarily.

[Mailanka]

I honestly have no idea what Arm DX does. I'm not really a fan of Arm DX or Arm ST outside of odd cases like cool cybernetic arms. So I've never used it outside of cyberpunk games or things inspired by them.

High Manual Dex intrigues me but I've never really found a place to make it work. It's not really a problem with finding a character who has high manual dex. It's finding a character who has high manual dex but lacks general dexterity. For example, your typical pick-pocket/lock-pick is also often paired up with general stealth, acrobatics and general infiltration skills/flexibility, as well as a few combat skills, so general DX makes more sense. Characters who are good at one thing, like the clock-maker or the surgeon, are generally better off just buying absurd levels of skill. It seems more appropriate for races, since it tends to push characters with those templates in directions that they might not take otherwise.