Charisma/Persuade/Intimidate checks in HU

[Boother]

Probably a very basic question, but it's got me scratching my head. I'm probably just missing something obvious, but here we are:

How to charisma/persuasion/intimidation-type roles work in HU?

I've got HU, the 1993 printing of I guess 1st edition? Anyways I'm not sure how to handle any sort of persuasion/charisma rolls. The table showing bonuses for stats that are exceptional, 17 or higher, has like 50% to persuade/intimidate for a MA or PB for 20 (or something around that, don't have the books with me at the moment).

but..is that like *plus*50%, but if so, plus 50% to WHAT? There's no 'persuasion' type skills listed in the skills section. If it's not intended to be +50%, but rather a flat 50%, that seems kind of low that a highly charismatic person would be 50/50 at best to succeed to persuade someone, but also how does it work for somebody who's not exceptionally charismatic? The table doesn't go below 17, so if a 9 or 10 is an 'average' person's stat, does that mean an average person can't try to even persuade someone? That doesn't seem right.

What am I missing here?

Thanks in advance.

[drewkitty ~..~]

The only text that even hints about how to use the MA and PB bonuses in any of the games that use the PB game system, is in the Ninja and Superspies game, in the Warrior's Spirit Kata. In this Kata, anyone perceiving the user has to roll % die over the kata user's accumulative intimidation % (nat. & kata bonus) or be intimidated.
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Note that some posters argue that that the mechanic in the warrior's spirit kata is only for that kata. But they don't cite text for any other 'normal use' or 'general use' mechanic for those attribute bonuses.
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There is a rifter article that sort of shows how a high charisma score can effect the story as a whole. (the macro scale)
However, it fails to have a explanation (game mechanic) about how the charisma score bonus is used on the individual level. (the individual/PvP scale)

[SpiritInterface]

I add it to skills like seduction, interrogation, public speaking, and other skills where the character is trying to influence a person or people through their looks (PB) or personality (MA). I use either as a offset of penalties or sometimes as a direct add, depending on the situation. The add is a representation of the raw influence an attractive or charismatic person has on others.

[Grazzik]

Since there is no HU canon on the issue... time for a house rule.

My house rule is that I consider it as a bonus similar to how SpiritInterface explained, but instead of applying to skills which can have pretty hefty numbers as it is, I add them to attribute checks for their respective attributes. That way, someone with a very high PB but no relevant skill can still charm even with serious context penalties - it is simply an innate aspect of their character. The thought is that why would someone who knows that they are innately intimidating/seductive spend the energy and time to learn what they are naturally good at already? The case could be made for those on the lower end of attribute bonuses, as they become more experienced, it may be more advantageous to rely on advanced techniques they learn through formal skills training in the arts of interrogation or seduction (basically leveling up their skill % higher than their att check threshold).