The past few years have seen an explosion of legislative activity around developments in genetics and assisted reproduction. In this chapter we examine recently passed legislation in Australia and Canada in the area of genetic modification technologies and reproductive genetics. We demonstrate that legislative control in this area has a twofold purpose. Less controversially it is aimed at providing limits to scientific innovation for the purpose of ensuring safe and ethical research and experimentation. More controversially it is concerned with what should be the proper “nature of reproduction,” namely, how it happens (sexually), between whom (a man and a woman, both human), in what kinds of relationships (heterosexual), such that progeny, the product of reproduction, inherit the blood/genes (bodily substances) of only two biological progenitors. It is to this latter purpose that we turn our attention in this chapter, analyzing the role of law in limiting, determining, and constituting reproductive possibilities in an age of genetic modification. Our focus is on new and potential technologies that enable inheritable genetic modification (IGM) of humans, but we read these, and their legislative limits, in the context in which they appear medically and legally, namely alongside other assisted reproductive technologies (ARTs) such as reproductive cloning. We ask what is at stake in the new legislative limits, who benefits, who loses, and what kinds of humans are we left with?