Attachment is the inborn bias of human children to seek the availability of familiar caregivers in times of stress. It has been observed from ancient times and in many cultures, and scaffolds further physical, cognitive, and socioemotional development. The security of these relationships is shaped by the continuity and quality of the child-rearing environment, and is independent of biological ties to the caregiver. In this chapter, the child’s right to a “good-enough”—that is, at least minimally adequate but not necessarily ‘best’--family life and the importance of a stable network of attachment relationships is highlighted. Legal issues raised by multi-parent care, including questions around the use of attachment-based assessments for custody decisions, are addressed. Attachment theory is well equipped to inform what caregiving arrangements children need, and legislators, judges, and lawyers may consult it as a source of insight into “good-enough” care arrangements in the interest of the child.