Claude "Cheat Codes" — 120 Tested Prompt Prefixes That Change How Claude Responds

You can ask Claude the same question two different ways and get two completely different answers. I don't mean rephrasing. I mean adding one tiny prefix in front of your prompt. The community has converged on about 120 of these "cheat codes" — none of them are official Anthropic features, but Claude consistently recognizes them. I spent 3 months testing which ones actually work. Here's the complete breakdown. What are Claude cheat codes? Short commands you put at the start of your message: Slash commands — /ghost , /skeptic , /punch , /noyap Uppercase keywords — L99 , ULTRATHINK , OODA , PERSONA , BEASTMODE Claude sees the prefix, recognizes the intent, and adjusts its behavior. The 5 you should learn first L99 Forces committed opinions instead of "it depends." L99 Should I use Postgres or MongoDB for a fintech startup? You get a real recommendation with specific tradeoffs, not a balanced pros-and-cons essay. PERSONA (with specificity) Generic: "Act like a database expert" → barely mov