Indonesia has a geothermal energy potential of 24 GW; however, two decades of development in the Dieng Geothermal Working Area (WKP) have been marred by H₂S gas leaks, aquifer contamination, and ecological conflicts, highlighting a legal gap between energy transition policies and the protection of community rights. This gap is reflected in the suboptimal regulations regarding legal protection, public participation, and state accountability for the extractive impacts of geothermal development. This study aims to analyze guarantees of legal protection and ecological justice for the people of Dieng, evaluate the effectiveness of the state accountability model, and formulate an ideal legal framework. The study employs a normative legal method with a legislative and conceptual approach, accompanied by descriptive-prescriptive analysis through content analysis of primary and secondary legal materials. The results indicate that legal protection guarantees remain ineffective because the centralization of permitting under Law No. 6 of 2023 limits public participation and weakens the preventive function of the Environmental Impact Assessment (EIA). The state accountability model is also ineffective as it continues to rely on proving fault following the erosion of the strict liability principle, thereby failing to provide optimal protection for affected communities. These research findings can serve as a basis for government policy to strengthen legal protection by reinstating the principle of strict liability, enhancing public participation based on Free, Prior, and Informed Consent (FPIC), and integrating a human rights perspective to achieve ecological justice.