Technology is a complex adaptive system that is both shaped by, and shapes, institutional arrangements. This critical insight, developed in depth by W. Brian Arthur – the father of complexity economics – is relevant to researchers interested in institutions. Arthur provides a method for capturing the underlying dynamics. He offers conceptual tools centred on the concept of increasing returns to make sense of some crucial challenges. He also suggests technical tools, including agent-based modelling, to tackle ill-defined economic, legal, and institutional problems. This article explores his body of work and derives some institutional insights from it.