Anthropic published its Responsible Scaling Policy (RSP), a framework that borrows from biosafety levels to define AI Safety Levels (ASL) tied to a model's dangerous capabilities, committing in advance to the safeguards and security standards required at each step. ASL-1 covers older models posing no meaningful catastrophic risk; ASL-2 covers systems showing early signs of dangerous capability, where Anthropic placed the Claude models of the time; ASL-3 covers systems that substantially raise catastrophic misuse risk; ASL-4 and above were left undefined. At ASL-3 the company committed to withhold deployment if red-teaming revealed meaningful catastrophic misuse risk. The policy required board approval, with changes requiring consultation with the Long-Term Benefit Trust. The approach of drawing lines in advance against measured capability became a template for later frameworks including OpenAI's Preparedness Framework and Google DeepMind's Frontier Safety Framework.