Autonomous delivery robots (ADRs) must share and negotiate for public and private space with pedestrians. Game theory shows that this requires making credible threats of inflicting at least small harms onto members of the public, which requires new legal justification. To this end, we argue that ADRs could be considered as pedestrians under existing law. We propose ‘robot self-defence’ and right to property as the legal basis for inflicting the required ‘small penalties.’ We examine the liability framework when an ADR actually causes a collision either deliberately through actualising a credible collision threat or accidentally via errors in controlling intended non-contact threats. We explore challenges around privacy and data protection where the ADR collects and uses data to model and predict interactions. Together, this provides a framework for legal operation of ADRs, including the ability to inflict small harm onto members of the public when necessary in negotiations for space.