We live in an era of experimentation - both if we look at the broader social world of politics, media and art and at the narrower context of academic knowledge production. This collection consists of 14 chapters by leading scholars in affect studies. They explore the affective dimensions of experimental practices related to, for example, activism, the COVID-19 pandemic, populism, sustainability, patient communities, music streaming, Jamaican dancehall, gangs, leadership, tourism and minority youth cultures. Experiments are understood as intentionally crafted milieus aimed at (re)presenting unnoticed aspects of the world, as non-linear processes with unpredictable outcomes, and as ways of giving the future a provisional form. The collection responds to a pressing need to understand the intersection between affect, experimentation and sociocultural change by offering empirical strategies to explore how, and with what consequences, experimentation is affective.