In this paper I will discuss two aspects of ignorance of the law: ignorance of illegality (including mistaking the law) and ignorance of the penalty; and I will look at the implications for natives, for tourists and for immigrants. I will argue that Carlos Nino's consensual theory of punishment need to rely on two premises in order to justify that (claiming) ignorance of the law is no excuse. The first premise explains why individuals are presumed to 'know' current laws. The (...) second premise explains why individuals are presumed to 'know' new legislation. (shrink)