  From a moral point of view, the rules of recognition, by themselves, cannot be regarded as sources of obligation to follow the law. Whether judges, or anybody else, should or should not respect the rules of recognition of a legal system, is ultimately a moral issue, that can only be resolved by moral arguments (concerning the age old issue of political obligation). And this is more generally so: the existence of a social practice, in itself, does not provide anyone with an obligation to engage in the practice. The rules of recognition only define what the practice is, and they can say nothing on the question of whether one should or should not engage in it. But of course, once one does engage in the practice, playing the role of judge or some other legal official, as it were, there are legal obligations defined by the rules of the game. In other words, there is nothing special in the idea of a legal obligation to follow the rules of recognition. The referee in a soccer game is equally obliged to follow the rules of his game, and the fact that the game is conventional poses no difficulty from this, let us say, “internal-player’s” perspective. But again, the constitutive rules of soccer cannot settle for anyone the question of whether they should play soccer or not. Similarly, the rules of recognition cannot settle for the judge, or anyone else for that matter, whether they should play by the rules of law, or not. They only tell us what the law is. Unlike chess or soccer, however, the law may well be a kind of game that people have an obligation to play, as it were. But if there is such an obligation, it must emerge from external, moral, considerations, that is, from a general moral obligation to obey the law. The complex question of whether there is such a general obligation to obey the law, and whether it depends on certain features of the relevant legal system, is extensively discussed in the literature on political obligation. A complete theory about the normativity of law must encompass these moral issues as well. (See the  entries on  political obligation  and  legal obligation.) 