While generative artificial intelligence (GenAI) poses significant societal challenges, its fundamental status as a tool remains unchanged. Clarifying tort liability determinations for GenAI conduct is therefore essential to properly guide its development. Distinct infringement risks emerge across operational phases—training, content generation, and data deletion—necessitating precise liability criteria, conduct assessments, and appropriate accountability mechanisms. Given the need for developmental regulation of emerging technologies, the fault liability principle best serves GenAI’s advancement. Implementation requires establishing a dual-phase, multi-tiered safety obligation framework for service providers to ensure reasonable constraints. For liability allocation, traditional tort law principles generally determine remedies; however, due to GenAI’s persistent infringement risks, joint liability and proportionate supplementary liability apply distinctly when service providers engage in indirect infringement.