[PK]

Originally Posted by vicky_molokh

I noticed an inconsistency:

I see no inconsistency here. Read on to see why.

BIO48 lists a scent-based version of Charisma (-20% for Scent-Based), setting the precedent that default Charisma is not Sense-Based.

No. It set the precedent that Charisma is not scent-based. Because it isn't. Thus, making it so is a -20% limitation. By way of comparison, you could not apply either Vision-Based or Hearing-Based to Charisma, because it more-or-less already has those limitations. (I only say "more-or-less" because it's the reaction modifier part that does, not the skill bonus.)

This is consistent with the description in Basic (where no inherent Sense-Based limitation is listed).

Actually, Charisma in the Basic Set states that you must "actively interact" with beings to get the reaction bonus -- and the only examples given there are for face-to-face interactions ("converse, lecture, etc."). This is because the intent of Charisma, as written in the Basic Set, has been that it improves such face-to-face interactions.

However, SE18 says that in effect

SE18 clarifies and makes explicit the situations under which Charisma comes into play. But it does so with full awareness of how Charisma is supposed to work. If Charisma's intent was "gives you +1 reactions everywhere, in every situation, with anyone seeing you, hearing you, or even just reading something you wrote," its cost would've be somewhere in the 10-15 point/level range!

it is highly problematic to stat up people who appear very charismatic in a chat (IRC etc.).

And that's appropriate. 93% of your intent in communication is conveyed via body language, tone of voice, etc. Trying to appear "charismatic" via chat or text message is like trying to appear "charismatic" via post-it-notes. If it's anything, it's Writing skill. (Realize that "he has charisma" does not mean "he has Charisma" -- the former is how people refer to anyone for whom they react positively.)

It also means that SE-Charisma is useless for TV stars, radio hosts, call centres

No, it's useful in that it boosts their Public Speaking. Such folks would be better off with Voice, mind you, but that's a no-brainer for someone who's mainly concerned with vocal interaction.

So . . . why?

Because it's important to clear up misconceptions. As you've shown here, many GURPS fans took away an overly broad interpretation of how Charisma was supposed to work, so it was SE's place to nail it down -- in part by giving Charisma an entire half-page write-up instead of the one paragraph that we had room for in the Basic Set.

If you want to ignore this clarification and treat Charisma as "+1 to reactions from anyone who sees you, hears you, reads your words, or even thinks of you" in your games, you can, but realize that Charisma is worth far more than the listed 5 points/level if that's the case.