Chatbots like ChatGPT are powerful because of their simplicity: Ask just about anything and you’ll get an answer. But the answer you get depends on a lot more than what you type.

Behind the scenes, artificial intelligence companies invisibly add thousands of words of instructions to every conversation you have with a chatbot to steer its behavior. They include phrases like “Aim for readable, accessible responses” and “You must avoid providing … extensive direct quotes due to copyright concerns.” Some can appear bizarre. The system prompt in OpenAI’s Codex coding assistant includes the command: “Never talk about goblins, gremlins, raccoons, trolls, ogres, pigeons, or other animals or creatures unless it is absolutely and unambiguously relevant to the user’s query.”

Those secret commands guide chatbots to behave as their makers intended, even if it conflicts with your own preferences. Understanding how these hidden instructions work — and how to add your own instructions into the system — can help you get more out of your chatbot.