How I Made AI Behave Differently Based on Conversation Context (Multi-Role Prompt Engineering)

I've been working on a project that requires multiple AI "characters" to behave differently in the same conversation — think of it like NPCs in a game, except each one needs to respond based on their role, personality, and the current situation. Here's what I learned about making this work reliably. The problem If you just tell an AI "you are character A" and "you are character B" in separate prompts, they all end up sounding the same. Generic. Helpful. Boring. You need them to have distinct beh