Being confronted to slow and dangerous mutations and to sudden and brutal shocks, and to have to cope with that has always been part of the reality of cities. They demonstrate a tremendous ability to resist, adapt and reborn. And yet, urban resilience is particularly topical today: the ever-increasing movement of urbanization, by concentrating population and economic and political centers, accentuates the character of the urban area at stake and contributes to increased risk; Cities are more than ever major players in risk management by providing a relevant and effective level of action and governance. The ambition to achieve zero risk is abandoned, as is the objective of perpetuating a territorial or social system in the same way: they are preferred to develop rebound and adaptation capacities. Beyond words and labels, how to achieve this goal of a state of dynamic equilibrium?