- Point 1 states that there must be a tribunal or officer with legal authority to determine rights and having a duty to act judicially. This establishes the type of body against which the writ can be issued – one that performs judicial or quasi-judicial functions. - Point 2 states that such body has acted without jurisdiction or in excess of jurisdiction. This is a primary ground for issuing certiorari; the body must have transgressed the limits of its legal authority.