POLITICS, LAW, ADMINISTRATION
I'm leaving the mechanics of this pretty open to interpretation, but here's some background.
POLITICS
President
The President is mostly a figurehead. The only regulation is that he or she must have been born within fifty miles of the city in order to stand for election. This is supposed to ensure that the High Council is managed by someone with local, rather than international, interests. There has very rarely been a President who did more than ribbon-cutting, and those who have tried have usually not lasted very long (Third President Alexander Yannatos exited his role particularly spectacularly, being drowned in a punch bowl; officially he died from the effects of drinking excessively. Well, yes...). But who's to say that can't change... The President can veto decisions of the High Council, or provide a tiebreak when the High Council cannot come to a decision. The President is elected (by the citizens of the city) for a five year term. A President can serve up to two terms.
High Council
The highest political body is made up of three ambassadors, one from each of the major Powers. They have little involvement in day-to-day running of the city, but of course they try to exert their influence over its governance in all sorts of ways. They are under a lot of pressure from their home governments too. They have the final say on legislation passed by the Common Council. They are also required to sign death warrants, though they don't (officially) have the power to overturn a death sentence; if they want to overturn a sentence, they must pass it to the President for his or her veto. The Council is appointed (by the respective governments of their empires) for a three year term. Each ambassador can serve up to two terms, but not consecutively - i.e., there must be a gap between their terms.
Common Council
The Common Council is made up of a body of 25 citizens of the city, elected by citizens of the city. Officially any citizen (see below for what this status means) can stand for election. Typically, the Common Council is made up of members of the craft and mercantile guilds and are usually from the wealthier and more powerful parts of the community. There are no political parties per se though factions tend to form within the Council and there's lots of manoeuvering before major votes. Members of the Council are entitled to support services in the form of administrators, secretaries etc. There are specific members elected (by the Council body) to the positions of Ministers for Trade, Education, Health and Public Works, Justice.
LAW
There are two types of courts: religious courts and the City Court. The City Court has a Low Court for more minor misdemeanours and a High Court for grievous crimes. The religious courts tend to deal with much day to day business and run in a systematic and organised way. Usually it's considered appropriate to be sentenced and punished by one's local community, which usually means one's religious court. The Low Court will deal with cases that cross religious communities and are also preferred for property disputes as they have expert property lawyers. All cases involving: murder, grievous bodily harm, rape, treason and grand larceny (and probably some other things I haven't thought of) are sent to the High Court.
Penalties for crimes from religious courts vary. Religious courts cannot sentence anyone to death - only the High Court has that power. They can, however, demand physical penance. Public penance, corporal punishment, fines and indentured service for fixed periods are the usual routes for punishment rather than prison time. Indentured service is the typical punishment of the City Court for crimes that don't deserve the death penalty (murder, treason), and the city makes extensive use of such servants for road repairs, street cleaning etc.
CITIZENS AND SUBJECTS
To be a citizen of the city you must either earn £500 per year or hold over £2000 (if for instance you were an heir, or you have a dowry). You must also have reached the age of 18. Being a citizen gives you the freedom of the city, which means you have the right to vote in elections and own property in the city.
Subjects of the city must be able to prove they earn over £150 per year or hold over £500, and also must be over the age of 18. Subjects are allowed to vote, but they are not allowed to own property within the city, which means subjects tend to either rent property or own homes outside the city limits.
People who are neither subjects nor citizens are known as aliens, even if they were born here. Aliens are not allowed to live within the city walls or to vote in elections. Some people of marginal status - i.e. just about able to afford subject status - opt not to because they will pay more taxes (see here), though usually it's seen as preferable to leave alien status behind if possible.
POLITICS
President
The President is mostly a figurehead. The only regulation is that he or she must have been born within fifty miles of the city in order to stand for election. This is supposed to ensure that the High Council is managed by someone with local, rather than international, interests. There has very rarely been a President who did more than ribbon-cutting, and those who have tried have usually not lasted very long (Third President Alexander Yannatos exited his role particularly spectacularly, being drowned in a punch bowl; officially he died from the effects of drinking excessively. Well, yes...). But who's to say that can't change... The President can veto decisions of the High Council, or provide a tiebreak when the High Council cannot come to a decision. The President is elected (by the citizens of the city) for a five year term. A President can serve up to two terms.
High Council
The highest political body is made up of three ambassadors, one from each of the major Powers. They have little involvement in day-to-day running of the city, but of course they try to exert their influence over its governance in all sorts of ways. They are under a lot of pressure from their home governments too. They have the final say on legislation passed by the Common Council. They are also required to sign death warrants, though they don't (officially) have the power to overturn a death sentence; if they want to overturn a sentence, they must pass it to the President for his or her veto. The Council is appointed (by the respective governments of their empires) for a three year term. Each ambassador can serve up to two terms, but not consecutively - i.e., there must be a gap between their terms.
Common Council
The Common Council is made up of a body of 25 citizens of the city, elected by citizens of the city. Officially any citizen (see below for what this status means) can stand for election. Typically, the Common Council is made up of members of the craft and mercantile guilds and are usually from the wealthier and more powerful parts of the community. There are no political parties per se though factions tend to form within the Council and there's lots of manoeuvering before major votes. Members of the Council are entitled to support services in the form of administrators, secretaries etc. There are specific members elected (by the Council body) to the positions of Ministers for Trade, Education, Health and Public Works, Justice.
LAW
There are two types of courts: religious courts and the City Court. The City Court has a Low Court for more minor misdemeanours and a High Court for grievous crimes. The religious courts tend to deal with much day to day business and run in a systematic and organised way. Usually it's considered appropriate to be sentenced and punished by one's local community, which usually means one's religious court. The Low Court will deal with cases that cross religious communities and are also preferred for property disputes as they have expert property lawyers. All cases involving: murder, grievous bodily harm, rape, treason and grand larceny (and probably some other things I haven't thought of) are sent to the High Court.
Penalties for crimes from religious courts vary. Religious courts cannot sentence anyone to death - only the High Court has that power. They can, however, demand physical penance. Public penance, corporal punishment, fines and indentured service for fixed periods are the usual routes for punishment rather than prison time. Indentured service is the typical punishment of the City Court for crimes that don't deserve the death penalty (murder, treason), and the city makes extensive use of such servants for road repairs, street cleaning etc.
CITIZENS AND SUBJECTS
To be a citizen of the city you must either earn £500 per year or hold over £2000 (if for instance you were an heir, or you have a dowry). You must also have reached the age of 18. Being a citizen gives you the freedom of the city, which means you have the right to vote in elections and own property in the city.
Subjects of the city must be able to prove they earn over £150 per year or hold over £500, and also must be over the age of 18. Subjects are allowed to vote, but they are not allowed to own property within the city, which means subjects tend to either rent property or own homes outside the city limits.
People who are neither subjects nor citizens are known as aliens, even if they were born here. Aliens are not allowed to live within the city walls or to vote in elections. Some people of marginal status - i.e. just about able to afford subject status - opt not to because they will pay more taxes (see here), though usually it's seen as preferable to leave alien status behind if possible.