The chief causae were rei gerundae (a general purpose, usually to lead an army in the field against a particular enemy), clavi figendi (an important religious rite involving the driving of a nail into the wall of the Temple of Jupiter Optimus Maximus), and comitiorum habendorum (the holding of the comitia to elect magistrates, when the consuls were unable to do so).
Other causae included ludorum faciendorum, holding the Ludi Romani (Roman games), an important religious festival; ferarium constituendarum (establishing a religious festival in response to serious prodigies); seditionis sedandae (quelling sedition); and in one remarkable case, senatus legendi (filling up the ranks of the Senate after the Battle of Cannae).
The causa given at the very end of the Republic for the dictatorships of Sulla and Caesar are completely novel, as the powers granted greatly exceeded those traditionally accorded a Roman dictator.
By legibus faciendis et rei publicae constituendae causa, Sulla was empowered to rewrite the laws and revise the constitution of the Roman state; by dictator perpetuo rei publicae constituendae causa, Caesar was appointed dictator in perpetuity, and given the power to revise the constitution.
The causae listed in the table are based largely on T. R. S. Broughton's The Magistrates of the Roman Republic, reporting those given in ancient sources.