Abstract. The immense technological advancements in the past decade have enabled robots to enjoy high levels of autonomy, paving their way into our society. The recent catastrophic accidents involving autonomous systems (e.g., Tesla fatal car accident), however, show that sole engineering progress in the technology is not enough to guarantee a safe and productive partnership between a human and a robot. In this paper we argue that we also need to advance our understanding of the role of social trust within human-robot relationships, and formulate a theory for expressing and reasoning about trust in the context of decisions affecting collaboration or competition between humans and robots. Therefore, we call for cross-disciplinary collaborations to study the formalization of social trust in the context of human-robot relationship. We lay the groundwork for such a study in this paper.