Decision-making about and for climate change adaptation has fascinated the field of adaptation science for decades. We now have a solid set of decision-support tools, frameworks and approaches available to support decision-makers. Yet, in this piece, I argue that the black box of decision-making requires unravelling for us to better understand what heuristics (rule of thumb) are used about climate adaptation and how these impact the very decisions made. I also point out areas in need of more research including a new focus on decision quality, artificial intelligence and data, and the role of imagination in driving climate adaptation decision-making.