Health innovation, Consoli and Mina argue, represents ‘complex bundles’ of new knowledge and services ‘emerging from a highly distributed competence base’ [1]. Complex systems theories have emerged from insights gained encompassing human behaviour, human values, evolutionary biological systems and statistical physics of the early complex systems theorists [2]. The recently published Handbook on Systems and Complexity in Health provides a broad overview and very detailed specific examples of the adoption and implementation of these sciences into the health professions [3]. Taking a broader view of health and care related to human systems than Consoli and Mina, these Forum papers reflect on a range of ‘complex bundles’ of innovation from a widely distributed knowledge base at population, clinical practice and biological levels. They illustrate the importance of using a complex systems lens to make sense of innovation and change in human systems. This is always a pressing challenge as health systems leaders and professionals continue to struggle to adapt to changing internal and external constraints. Inequalities, fairness and justice are important dynamic elements of human health systems, as change invariably causes shifts among intended and unexpected interdependent agencies. Buse [4] and Reynolds [5] have explored case studies of phenomena that impact on the health of individuals and populations. At a macro-population level, Buse [4] examines the contribution of intersectoral action for health equity, as it relates to climate change through the lens of critical heuristics (CSH) – viewed holistically and through multiple lenses, and rejecting reductionist analyses that predefine a system according to its parts. Systems thinking in general seeks to understand an issue as more than the sum of its parts. Accounting for the human dimension of social systems, ‘CSH provides three overarching contributions to the systems literature: a fundamental commitment to emancipation through practical action; critical awareness; and methodological pluralism’ [4]. Reynolds [5], in an entirely different area, explores the nature of fairness and conflicting value systems in hospital charity lotteries, which provide money for selective popular health services but may undermine individuals’ health potentials in the process. This raises the challenges of contradictions and tensions in dynamic health systems. Norman [6] provides a personal analysis of his role as an educator, promoting systems thinking in population health education, and reflects on the work of Buse and Reynolds. He highlights the fact that the challenges in education for systems thinking reach beyond overcoming resistance in social and professional acceptance, to encompass balancing new ideas, seeing existing ideas in new ways and ‘unlearning’ others. Techniques are needed to educate students to be open, responsive and adaptive in their thinking, and to embrace contradictions, tensions and changing dynamics of ‘bundles of knowledge’ in different competency domains. Health professionals need to demonstrate capability as much as competence. New ways of teaching and learning with curricula and learning materials need to be developed. At the level of clinical practice, Persky et al. [7] examine communication between residents and attending doctors on-call after hours in the light of existing local guidelines. Surveys were conducted with residents about their expectations and experiences of interactions with attending doctors. The study found considerable variability among reported experiences in relation to different specialities, individual resident expectations and attending doctor’s reported behaviour. The authors identify that the communication has complex social dynamics. They hypothesized about the contribution of power and deference, as well as variations in resident’s self-confidence and perceived competence to undermining adherence to local guidelines. Interestingly, they propose that the solution to the perceived complexity is the enforcement of greater regulation. This is a typical and bureaucratic response to complex situations identified in the Cynefin framework [8] See Fig. 1. However, there are potentially a range of opportunities for solutions other than regulatory, using creativity and trial and error. Finally, reflecting the need to better understand how to characterize complex systems of biometric properties in health care, bs_bs_banner