Despite climate catastrophes, increasing inequality and growing geopolitical instability, architecture remains stubbornly optimistic about the future. More than this: it usually sees itself as the discipline best capable of showing society a way out of disaster. Optimism seems to be a genuine ‘strategy’ that strongly shapes architectural and urban design practice. We can hardly imagine a different – and hopefully better – built future if we are not optimistic about it and believe in it ourselves. This issue of OASE focuses on the specific position of optimism in architecture and urban design. Where in the design and construction process is it hiding? In what circumstances does it rear its head? What causes it to be sidelined? How do design practices change under the yoke of optimism? How do boldly optimistic choices manifest in projects? And how persistent is this ever-good-natured optimism in the face of a fickle reality?