Adjacent, i.e., nearby, possibilities constantly emerge in a multitude of settings for a multitude of entities. When these possibilities are explored, yet new possibilities emerge. The concept of the “adjacent possible” was introduced by Stuart Kauffman (1996; 2000) in evolutionary biology and complex adaptive systems to explain how biological evolution can be seen as exploration and actualization of what is adjacent possible, i.e., available at hand. The concept has now disseminated into a wide range of research fields including economy, innovation studies, technological evolution, cultural evolution, learning processes, recommender systems, and design studies.

The “adjacent possible” can be defined as “the set of possibilities available to individuals, communities, institutions, organisms, productive processes, etc., at a given point in time during their evolution” (Loreto 2015, p. 9). The concept of the “adjacent possible” is useful for understanding how new possibilities emerge, and how they are constrained, discovered, explored, actualized, developed, reconfigured, designed, and so on, in an interplay between what is actual and what is possible for specific entities in specific settings.

In this entry, the history and the state of art of research on the “adjacent possible” is briefly outlined. Discussion focuses on four essential aspects of “adjacent possibles”: (1) topologies of “adjacent possibles,” (2) types of “adjacent possibles,” (3) serendipity as actualization of “adjacent possibles,” and (4) designing for “adjacent possibles.”