As defined by 3.5 PHB
Charisma measures a character’s force of personality, persuasiveness, personal magnetism, ability to lead, and physical attractiveness. This ability represents actual strength of personality, not merely how one is perceived by others in a social setting. Charisma is most important for paladins, sorcerers, and bards. It is also important for clerics, since it affects their ability to turn undead. Every creature has a Charisma score.
On one hand, charisma is the power of your personality, how well you influence others.
But also, charisma is how attractive you are.
I know that the "attractive" bit doesn't really have any effect on the game from a numbers perspective, but it does affect how you interact with PCs and NPCs.
Some people don't believe it is fair that just because they have a low charisma, their character should be ugly, and neither do I. So the way I view charisma is that you are either influencing, inspiring, etc.. through either your personality (think William Wallace), through sheer good looks (think Zapp Brannigan), or some combination of both. Now I know that none of this actually affects the mechanics of the game, but D&D isn't just about mechanics; it's about role-playing that character for a few to 12 hours at a time.
The simple little way I like to set up charisma as both a DM and a PC (note: as a PC, just explain this to the DM; if they have an issue with it, remember: they are god. There's nothing you can do):
I spilt my charisma into two different parts: looks and personality. Since the average score of a human is 10, that would mean 5 in looks is average and 5 in personality is average.
If you're a fighter with a charisma of 7 and you don't want to be ugly, just put 5 points in looks, and 2 into personality (that means you look average, but you are bad with people).
Ideas for RP,
- A Bard with a charisma of 17 (16 in looks, 1 in personality) have Gaston like personality, you are abrasive and you think the world revolves around you.
- A Wizard with a 12 in charisma (10 in looks, 2 in personality) you are a book worm you talk way above peoples intelligence and it rubs people the wrong way, but you are good looking so people put up with it.
That's it. Like I said: simple, but it's a lot more clear for the DM and other players to know why you can influence people the way you do. If you have questions or comments leave them below or message me on my reddit.
P.S. I claim no ownership to this system or originality, I just picked it up over time.
-Thanks for reading