The understanding and skills needed to compete in today's global economy are arguably quite different to those upon which 19th and 20th century education systems have traditionally focussed. Life has become much more international, multicultural and inter-connected. Seismic advances have occurred in ICT and in access to it. These have enabled the economies of developed countries, including the UK's, to shift from a basis of material goods and services to one of information and knowledge. The aim of this article is to explore some of the benefits and risks of building pedagogies and curricula around 21st Century skills. I begin by outlining some conceptualisations of 21st Century skills. I then address the question of how their development in young people can best be supported; I describe recent examples of alternative approaches used in the UK and internationally, including extended projects for sixth-form students. I also start to consider the value placed by stakeholders on the summative assessment of 21st Century skills, and finally, the feasibility of such assessment for test developers.