Please explain to me Martial Arts styles' optional traits
 

Hello,
I am enjoying Martial Arts but I have a doubt about styles and the optional traits. I understand that skills are depending on "setting" if they are requested or not, but about advantages and disadvantages, how do they work?
Do characters taking the styles automatically and for free taking those advantages and disadvantages, or are something to eventually add as of the skills, increasing the cost of the overall style?
In case the advantages are something that come for free learning the style, isn't it a huge advantage in term of points spending?

Re: Please explain to me Martial Arts styles' optional traits
 

Nothing is ever, ever 'for free'.

Those are just suggested traits a practitioner of the style might have. That's all. Maybe if you need a justification for someone adding those traits, practicing a style for which they are mentioned could be such a justification.

Re: Please explain to me Martial Arts styles' optional traits
 

If your GM insists on an in-universe justification for specific training before you spend your points, the optional traits can help provide guidance as to what's available.

Re: Please explain to me Martial Arts styles' optional traits
 

Thanks.
I was just overcomplicating myself xD
So one pays for the familiarity and needed skills, the optional traits for the campaign and gains the techniques?

Re: Please explain to me Martial Arts styles' optional traits
 

You don't need to buy the optional traits, that's why they're optional (though yes, some campaigns do make some optional traits Required or Recommended). You buy the required skills and get the techniques that default from them at default level (and should probably buy up one or more of the techniques that you're going to use a lot, especially if it has a high penalty). You decide for yourself whether to get the optional ones, as long as they haven't been switched to required.

Re: Please explain to me Martial Arts styles' optional traits
 

Note that most techniques are Hard, and it costs 2 points to buy the first +1. So raising two of them costs 4 points. But for 4 points you could get +1 to the underlying skill and thus to ALL the techniques that default from it.

You can efficiently buy one Hard technique, or one Hard and one Average, or three Average. Raising one Hard technique gives you a distinctive specialization as a character, which seems about right.

Re: Please explain to me Martial Arts styles' optional traits
 

Anyone can use any technique. Techniques in a martial art style are the ones that style teaches and so can be legitimately bought up. You still have to pay the points. The only things you get from the points you pay for the martial art style are: a) one point in each of the skills taught by the martial art style (I'm too lazy to look up if the 3E version's idea that you could take points out of one skill and apply them to other skills or techniques carried over, but I don't think it did), and b) the style perk for that martial art style. You can then pay more points for more skill, to increase technique defaults, to get optional traits, or whatever.

Re: Please explain to me Martial Arts styles' optional traits
 

See "Buying a style", on p. 146 of Martial Arts.

The "cost" of a style is just a shorthand for a point for Style Familiarity, plus a point in each of the style's skills. When you have bought all of those things, you have the style. Of course, you'll probably want to spend more points on some of the skills, maybe buy up a technique or two and consider buying some of the optional traits.

Just as it's perfectly possible in GURPS to be a magician with no combat magic, it's equally possible to be a martial artist who isn't much good at serious fighting. It's part of being generic and universal.

Re: Please explain to me Martial Arts styles' optional traits
 

On a role-playing/world-building front, Optional Traits are also a nice way to make different "schools" (use appropriate term for given style) within a style.

Both Master John and Master Jane might teach the same style at their respective schools, but the students of the two schools will learn slightly different techniques or put more emphasis on certain things over the other. For example, Master Jane's school might not care much about the ancient traditions of her style and focus much more about self-defense and full-contact sparing giving most of her students the "Optional" advantages of Combat Reflexes and High Pain Threshold, while Master John may be much more traditional and insist that all of his students learn the "Optional" Language, Meditation skill and Philosophy skill. The GM can accentuate the differences between schools of the same style by sliding different optional traits from the style's list of optional traits into their curriculum (effectively making them required for that school, but not necessarily for the style writ-large)

Re: Please explain to me Martial Arts styles' optional traits
 

It's a little more complex than that. (a) It's never worth buying up any techniques before you have at least 2 points in the underlying skill, and usually 4. (b) It may be worth buying two or even three Hard techniques if you want to raise them by more than +1 and the underlying skill already has four or more points invested in it.

Say you are a Jujutsu stylist with DX 12 and Judo at 12, which cost you 4 points. That gives you Disarming (Judo)-12, Low Fighting-10. You want to add +2 to both techniques. You could get that by raising Judo to 14, but that would cost you 8 points; alternatively, you could buy up the techniques individually, for 3 points each, total 6 points. It gets even better if you want to raise the techniques further above default...

Optimising this stuff gets fiddly (to the point of being the sort of thing that gets GURPS a bad name for number-crunching), and the best rule of thumb remains "only buy up one technique per skill", but you can't assume that someone who's bought up several techniques has made a mistake.

Re: Please explain to me Martial Arts styles' optional traits
 

Techniques that buy off potentially stacking penalties also alter the math. If you want to specialize in close combat counterattacks while sitting...

Re: Please explain to me Martial Arts styles' optional traits
 

You can efficiently raise two or three Hard techniques as long as you raise them both by at least +2 and you use them almost every time you use the skill. Also, if one of the techniques is harder than the other(s) raising it until it matches the penalties of the rest and then switching to raising the overall skill can be efficient even though you have 'too many' techniques.

To me techniques are clearly intended to be for that one (or maybe two) thing(s) that a character does with a skill that stands out from their overall level of skill. Thus they shouldn't be cheap enough that a character can (and should) have many of them for each skill. Aside from anything else, that encourages enormously fiddly character builds.