Any scenario of urban futures outlined in this Report will face unexpected shocks and stresses. Will a given city collapse like a house of cards or withstand whatever unpredictable future comes their way? The answer to that question lies in a city's resilience, a capacity that bookends all of the discussion up to this point. A key message running through this Report is that building economic, social and environmental resilience, including appropriate governance and institutional structures must be at the heart of the future of cities. Cities that are well-planned, managed, and financed have a strong foundation to prepare for such unknown future threats. Moreover, cities that are socially inclusive and work for all their residents are also better positioned to face environmental, public health, economic, social and any other variety of shock or stress, as cities are only as strong as their weakest link.