Mounting climate-related floods, fires, droughts and storms across the globe raise crucial questions about the role of law in adjudicating rights and obligations. While climate litigation attracts scholarly attention, vulnerable populations often lack the means to use formal laws and courts. We draw on ethnographic interviews conducted in 2022 in the city of Cartagena, Colombia, to study how residents of informal settlements exposed to flooding resist exclusionary climate adaptation laws. The findings show how formal law has exacerbated differential climate vulnerability, and resulted in “seawalls for the rich, relocation (and stalled adaptation) for the poor.” In this context, residents claim land in risk-zones through a local rule system known as “the law of the four poles.” We argue that by challenging the legality of the state, and creating a rival legal order that better represents locally identified interests and entitlements, they are claiming a political voice in climate adaptation. We advance theory in both climate adaptation and sociology of law and discuss how the law can better reflect not only the science behind climate change but also the interest and needs of marginalized communities.