The praetorship was created in around 367–366 BC to take over part of the duties of the consuls. Praetors acted as deputies and colleagues to the consuls who led the republic. In the year 246 BC the Senate created another Praetura. There were two reasons for this: to relieve the weight of judicial business and to give the Republic a magistrate with imperium who could field an army in an emergency when both consuls were fighting a far-off war. By the end of the First Punic War the designation Praetor peregrinus and Praetor urbanus was created.
The Praetor peregrinus had jurisdiction in legal disputes between citizens and noncitizens. This praetor was also available to command legions when the consuls were away or unable to do so. Conversly, the Praetor urbanus presided in civil cases between citizens and was charged wth the defence of the city when the consuls were abscent and the organization of some annual festivals (ludi).
Praetors had the ability to screen legal cases before allowing them to proceed the courts. If a case went to court they appointed a judge (Iudex) to oversee the case. Praetors also issues edicts which assisted in interpreting and defining the law.Within the Modern Res publica:
The praetors act as deputies to the consuls assisting with the administration of the res publica on a daily basis. One Praetor Urbanus and one Praetor Peregrinus is elected.
The Praetor Peregrinus is responsible for civil judicial cases between a citizen and non-citizen, or any case where at least one party is a non-elected appointed magistrate or a provincial administration. They are also responsible for cases referred by the Plebeian Aedile for appeal and the legal activities of the societas. This praetor also is responsible for public judicial cases dealing with: threatening the wellbeing of a citizen, forgery or false information, destruction of state property, and purposeful harm to the cultus deorum romanum.
The Praetor Urbanus is responsible for civil judicial cases between two citizens or any case where at least one party is a senator or an elected magistrate. They also manage cases referred by the Curule Aedile for appeal and organize the festival the Ludi Apollinares. This office also manages the legal activities of any registered collegium. This praetor is also responsible for public judicial cases dealing with: treason, physical injury to a citizen, extortion by state magistrates and staff, embezzlement or misuse of state funds or offices, and electoral corruption.
Both praetors are have the duty of insuring all laws, edicts and legally binding announcements are up to date on the main web site and to also moderate the activity of the main forum. They also both have the ability to summon the senate, propose new legislation and to call the Centuriate and Tribal assemblies. The specific duties of the praetors are exchangeable if both praetors agree or if one praetor is unavailable.
In the res publica two praetors are elected for a term of one year by the Centuriate Assembly.