The aims of this article are twofold: (i) to propose an explanatory framework, focusing on law-making acts, for accounting for whether the formal requirements of the rule of law are fulfilled; and (ii) to propose two further models within this framework. One model, which I call 'rulebook formalism', pertains to Parliament's law-making acts; another model, which I call 'rights formalism', concerns the courts' law-making acts. This distinction results from the different modality of law, ie the different natures of law-making acts. Drawing on speech act theory, I give a general account of the formal requirements as the success conditions of law-making acts. Then, applying this framework, I discuss the formal requirements for Parliament's law-making acts and the courts' law-making acts respectively.