This chapter advocates strategic conceptual engineering, that is, the employment of a (possibly novel) concept for specific epistemic or social aims, concomitant with the openness to use a different concept for other contexts. We illustrate this approach by sketching three distinct concepts of gender and arguing that all of them are needed, as they answer to different social aims. The first concept serves the aim of identifying and explaining gender-based discrimination. It is similar to Haslanger’s account, except that rather than offering a definition of ‘woman’ we focus on ‘gender’ as one among several axes of discrimination. The second concept of gender is to assign legal rights and social recognitions, and is to be trans-inclusive. We argue that this cannot be achieved by previously suggested concepts (including Jenkins’s) that include substantial gender-related psychological features or awareness of social expectations. The third concept of gender serves the aim of personal empowerment through gender identity. This chapter points to contexts where a concept’s role in explanation and moral reasoning can be more important than determining the extensions of concepts.