Within the vast landscape of the Built Environment, where challenges of uncertainty abound, this paper ventures into a detailed exploration of antifragile planning. Antifragility, a concept rooted in the capacity of systems to not only withstand but also thrive in the face of volatility, stands as a beacon of resilience amidst the uncertainties of the Anthropocene. The paper offers a systematic examination of antifragile planning, specifically by concentrating on uncertainty as one of its key theoretical tenets and by exploring the implications of these principles within the context of the Anthropocene. After offering a systematic and comprehensive review of the literature, the analysis delves into several important themes in antifragile planning, including the recognition of limited predictive reliability, critiques of conventional responses to shocks such as urban resilience and smart cities, and the strategic elimination of potential fragilizers through a unique planning methodology. Furthermore, the paper discusses three key arguments challenging the efficacy of antifragility: the systemic approach, the classification of responses to perturbations, and the validity of adaptivity and optionality theses. Specifically, the gaps identified in the antifragile planning methodology reveal its shortcomings in addressing the complexity of cities, its failure to recognize the variety of responses to shocks and perturbations, and its neglect of broader urban relationalities, especially in relation to climate-induced uncertainty. Thus, it is asserted that antifragility remains urbocentric. For these reasons, the paper contends that rectifying the gaps detected in antifragility is necessary to address the uncertainty of the Anthropocene. By aligning largely with emerging posthumanist planning strategies, the paper emphasizes the significance of adopting a proactive approach that goes beyond merely suppressing natural events. This approach involves fostering urban intelligence, contextualizing urban materialities within broader planetary dynamics, and embracing exploratory design strategies that prioritize both the ethical and aesthetic dimensions of planning.