What does the dragon you're negotiating ransom with care that you're the third son of the Baroness of Crumpet? Why isn't the innkeeper deferring to you because you are? Why do you still have an 18 charisma after you led that disastrous foray against said dragon?
For Epirus Nova, I'm leaving the basic Charisma score alone. It reflects your force of personality that you can get across to any intelligent creature. However I'm going to add an Influence modifier, that may be used when dealing with other members of society. It's applicability outside of your character's society is at the DMs discretion.
The components of Influence are Citizenship, Social Status, Wealth and Success.
CitizenshipA great differentiator in the Roman world, if I recall my Bible correctly, the Apostle Paul was able to avoid immediate execution in favor of being sent to Rome, because he was a Roman citizen. The Grades of citizenship in descending order are Roman - enjoying full legal protection; Latin - Full legal protection under Roman law, not allowed to marry Roman citizens; Socii - citizens of Roman allies with defined legal rights; Foederati - citizens of conquered and subsequently allied states and Provinciales - any one without defined rights, who is subject to Roman control or jurisdiction. Now, the distinction I'm drawing between Socii and Foederati wasn't as clear cut as I have made it; but this way is easier from the standpoint of game mechanics,
Social StatusIn the Republic this was a matter of birth, wealth, family history and getting elected. At the top of the heap was any one who who has Imperium, that is a legal power to command others with in the boundaries of their duties. It exists in varying degrees that are not important to this discussion. Usually it is held by an individual as a virtue of the office to which they have been elected, such as Consul. Grants of Imperium could be tailored to the task on hand. Pompey the Great received a grant of Imperium in all territories within 50 miles of the sea when he was tasked with suppressing piracy. Anyone with Imperium has the power to impose capital punishment outside of Rome itself. Usually, held by men of Senatorial rank, however Equites were occasionally elected to offices with Imperium. Non-Roman kings and tyrants are at this level.
Below holders of Imperium, comes the Senate. There are two classes with in this category, regular and Nobles. Noble Senators either had held a Consulship or had an ancestor who had been a Consul. The minimum property qualification for a Senator is 1,000,000 GP. this is anachronism, the requirement of 1,000,000 sesterces didn't come about until the Empire and the sesterce was a small silver coin. Again, game mechanics. Non-Roman oligarchs, upper and lower nobility.
Below the Senate are the Equites or 'Horsemen', they have a minimum wealth of 400,000 GP. Non-Roman knights.
Not quite at the bottom are the Plebs, or commons. With game mechanics in mind, I'm sub dividing these into Plebs who meet wealth thresholds, then Plebs who are clients of someone higher in the social order and unaligned Plebs. The Patron/Client relationship was very important in the Roman society. Having a patron meant you had a friend in court, some one who could loan you money, in return for which you provided political support and attended on them in public functions. Of course, if you had the money yourself, you could function as a patron yourself.
Below the Plebs are the Freedmen and finally the Slaves.
Throwing it into a table:
|9||Senator - Noble||Imperium|
|8||Senator||Senator - Noble||Imperium|
|6||Pleb 300K gp||Equites||Senator||Senator-Noble||Imperium|
|5||Pleb 200K gp||Pleb 300K gp||Equites||Senator||Senator-Noble|
|4||Pleb 100K gp||Pleb 200K gp||Pleb 200K gp||Equites||Senator|
|3||Pleb 40K gp||Pleb 100K gp||Pleb 100K gp||Pleb 200K gp||Equites|
|2||Pleb 20K gp||Pleb 40K gp||Pleb 40K gp||Pleb 40K gp||Pleb 200K gp|
|1||Pleb - Client||Pleb - Client||Pleb - Client||Pleb - Client||Pleb - Client|