The Low Charisma Excuse

I just saw a post where a person was asking for advice given that they were about to be in a game with someone who treated them horribly in another game with the excuse that they had low Charisma and there for it was in character for them to be a jerk.

This is an excuse and is no reason for a person to treat anybody horribly.

I am going to use D&D as my focus here but this really applies to any game system. Ability Scores can be used to inform some of a character's personality but they are, first and foremost, a measurement of how effectively they are able to handle tasks in that category. To target Charisma specifically, that is a measure of how capable a character is at getting people to do what they want.

A person with low Charisma is unlikely to be able to convince people to go along with their ideas when it comes to a roll. There any of a number of reasons for why this could be.

A person could indeed be a jerk who insults people all the time and thus he makes people angry and it causes people not to agree with him.

However, a low Charisma individual could also be a total wallflower, incredibly shy and having difficulty making themselves heard.

They could also be very energetic and demanding but for some reason no one takes them seriously. Maybe they look too young, maybe they are assumed to be too cute, or something like that.

There are endless ways to represent the fact that your character sucks at convincing people to do what they want. 

Likewise, a high Charisma could be someone with honeyed tongue who has an easy time charming people.

Or they could be an unapologetic jerk who none-the-less makes good points and makes people listen to him even as he's insulting them and even while they're getting pissed at him, they're realizing he has a point.

Being a jerk is entirely a choice.

Likewise, a player that uses low-Charisma to explain why he steamrolls all over his team-members is circumventing their low score because by stats, he shouldn't be able to steamroll them with low Charisma. He should be a frustrated jerk whom no one listens to.

Likewise, Intelligence and Wisdom can be also be explained in multiple ways.

A person with low Intelligence might be an incredibly well educated person who refuses to deviate his understanding from the books he read in his studies even when encountering the real phenomena or creatures shows that his studies were completely erroneous. He will insist that that tiger is behaving entirely incorrectly and shouldn't be able to swim at all. 

Likewise, a high Intelligence person might be incredibly uneducated and speak in a terribly poor manner but still have a plethora of knowledge based on stuff they've actually witnessed and remember well. They might have an amazing memory and and an innate understanding of logic even if they haven't picked up good grammar.

A person with low Wisdom might be constantly contemplating lofty things to the point that they pay no attention to their surroundings and are easily psychically manipulated during their naval gazing. An outsider who encounters them at first might take them to be a deep thinker of great wisdom because they ponder existential issues even when they don't know that feeding wild animals is a bad idea. They might say many profound but useless things.

A person with high Wisdom might be someone whose philosophy doesn't seem to extend far past barstool philosophy on first brush but their advice, while very brusque and unflowery often proves to be useful in multiple circumstances. Likewise, they pay attention to the world around them and notice problems coming their way. Nor are they easily fooled. They may have an odd appreciation for fart jokes but they have all the practical traits needed for reading people and other such things.

When someone says they are being a jerk to be in character with their low Charisma they may be telling the truth, or they may be making an excuse. Someone who is just playing in character should be willing to alter the way they play so that they are not making things less fun for other people.

A jerk character should be something that all the other players find amusing or interesting. If the behavior is causing a player to have less fun then it isn't acceptable roleplaying.