Investigating the complexity of grammatical gender begins with the question: What are the dimensions of variation? This question is addressed by Canonical Typology, which provides us with a cross-linguistic road map of gender systems (Corbett & Fedden 2016). Compass and measuring rod are the principles of canonicity, which organise the theoretical space around a canonical centre and then situate real gen- der systems in this space. In this chapter I compare and contrast the principles of canonicity with those of complexity, and discuss both of them in relation to difficulty. While canonicity, complexity, and difficulty are related notions, it will be argued that they are not identical: individual phenomena can be complex but canonical, or complex but not difficult. The aim of the chapter is to tease apart issues of methodology, description, and theory in order to arrive at a clearer un- derstanding of the complexity of gender.