Multi-Agent Debate
One model gives you one answer, delivered with the same confidence whether it is right or wrong. Multi-agent debate takes another route: run several instances on the same question, show each of them what the others said, and let them argue it out before anything is returned.
How a round works
The structure is deliberately simple:
- each agent answers independently first, so none of them is anchored to another's opinion;
- each then receives the others' answers with their reasoning, and is asked to critique them and revise its own;
- the loop repeats for a fixed number of rounds and ends on convergence, a majority vote, or a separate judge model's call.
Published work on the method (Du and colleagues, 2023) reported accuracy gains on arithmetic and factual-recall tasks over a single pass.
What it buys and what it costs
Debate spends inference to catch the errors that survive one attempt but not scrutiny — a wrong intermediate step, a half-remembered fact — and the bill is agents multiplied by rounds, in tokens and in latency. Its characteristic failure is conformity: the agents converge politely on a confidently wrong answer and the agreement reads as evidence. Keeping the first round independent, asking explicitly for disagreement, and giving the final call to a judge rather than to consensus all push against that. It differs from self-consistency, which samples many answers and votes but never lets them see one another.
Multi-agent debate runs several model instances on the same question, shows each one the others' answers and reasoning, and has them critique and revise over a fixed number of rounds before a vote or a judge settles it. It spends extra inference to catch errors that survive a single pass. The risk is conformity: the agents converge politely on a wrong answer, and the agreement gets mistaken for evidence.
Ask one friend a tricky question and you get one answer. Ask five and let them argue about it, and the weak answers usually get picked apart.
Multi-agent debate does that with AI. The same question goes to several copies of the AI. Each one answers on its own first, then sees what the others said and is asked to challenge them and think again. After a round or two, a vote or a referee picks the answer that survived.
It costs several times the work for one answer, and it has a weakness worth knowing: the copies can talk each other into the same wrong answer and sound very sure about it.