Mastering Turn-Taking in Group Chat: How Two Characters Share One Thread

Mastering Turn-Taking in Group Chat: How Two Characters Share One Thread Building a seamless group chat experience where two characters share a single thread can be surprisingly tricky. While one-on-one conversations with AI are relatively straightforward, introducing a second AI persona into the same chat thread raises a fundamental question: when a user speaks, who answers? We recently launched multi-character rooms on AmorLink, and this article delves into the turn-taking logic we developed. You'll discover why the majority of this logic deliberately avoids calling a language model and explore the contextual challenges that proved more complex than the routing itself. The Pitfalls of Simple Solutions The most intuitive approach is to have "everyone answer every message." However, this quickly devolves into a "press conference" scenario. Imagine asking, "How was your day?" and receiving two stacked paragraphs, each completely unaware of the other. This method also doubles inference costs and increases the time-to-first-token for every turn. Another common, yet flawed, strategy is to "pick at random." While cheaper, it's often more frustrating. If a user asks, "Iris, what do you think?" and the other character answers, the illusion of intelligent conversation shatters instantly. Randomness offers no improvement as the conversation scales. A Ladder Approach to Turn-Taking The key insight is that turn-taking isn't a single problem but a stack of them. The vast majority of these problems have unambiguous solutions. For instance, if a message explicitly names a character or is very short and follows a reply, the decision is clear. Only a minority of turns genuinely require complex judgment. Therefore, our policy is structured as a ladder, prioritizing cost-effective solutions for easy cases and reserving the more expensive AI model for the difficult ones. Our five-rung ladder works as follows, with the first matching condition determining the response: Exactly one memb