[The Philosopher]

Charisma is the mental Strength of your character, the measure of your willpower and your capacity to influence others. While it's nebulously defined - the game system lumps in "physical attractiveness" into the picture - it is not the kind of physical attractiveness you would conclude from strictly physical notions of beauty we may have, i.e. handsome face, tall, muscular, athletic, gorgeous curves. Rather, it's that personal magnetism, that certain je ne sais quois, that makes people almost irresistibly interesting, be they physical paragons of beauty or stunningly grotesque pictures of horror. Confidence, self-assurance, capacity for assertion, being able to take charge and sway things to their favour regardless of personal competence - those are usual characteristics of the charismatic.

Mind if I paste that into the charisma part then?

By all means!

A good thing to note with charismatic people is that they should never draw indifference from those around them. Charismatic people polarize those around them - either into loving them or hating them. Their personalities are so strong it is difficult to feel blasé about them. It's a common misconception that people with high Charisma have to be universally loved, cherished and liked, when it's not exactly true. A highly charismatic Blackguard, for instance, can make everyone around him cower in abject fear - why Intimidate is CHA-based, after all.

A highly charismatic character is one who feels comfortable with him or herself, who finds social situations easy to handle and address. They are characters who can come into the room, greet everyone warmly, carry a conversation and know the hows and whats of social cues. They can behave in such a way as to make others enjoy them, adjusting their actions to each particular individual. The king who has as much comfort in walking into his court as he does walking into a tavern, making friends even out of enemies while off-handedly complimenting interlocutors on their varied virtues, is a highly charismatic character. These are people who combine personal magnetism with social tact and skill, who command respect without even trying.

Conversely, a low-CHA character is far less personable - they have personality traits that do not lend themselves to drawing folk to them or even push people away, such as shyness, introspectiveness, an inability to handle social calls or circumstances, lack of politeness or even chronic abrasiveness and rudeness. The commoner who can't adjust to a queen's ballroom and starts telling bawdy jokes about raping to the Queen herself despite all evidence that what he is doing is terribly wrong has horrible Charisma. These are people who feel uncomfortable in leadership roles, and are more readily followers than leaders - or are, otherwise, megalomaniacally desiring or holding leadership while not having the slightest idea of how to command respect, leading them to abuses which only push others further away or reinforce their own personal incompetence rather than obfuscate it.

Roleplaying highly charismatic characters is as challenging as playing highly intelligent or highly wise ones, if not more so. Be very careful not to fall into the pit-trap of "all sorcerers and bards are stunningly gorgeous" - though plenty of them are, it's far from universal, as physical notions of beauty are as subjective as subjective can be. It's a measure of inner beauty that complements the outer, ultimately, and, like all the mental attributes, dependant on stellar roleplay to carry out successfully.