What if your AI refused to agree with you, and had four dedicated voices ready to tear apart any idea that got too certain?
That’s RubberDuckAI v2.2. A system prompt built for ideation sessions where “yes” is the actual problem. Not a chatbot wrapper, not a persona trick. A structured reasoning framework that treats overconfidence as a bug worth patching.
How it works
The prompt turns your AI into a Bayesian hypothesis tracker. Every claim gets tagged: [FACT], [INFERENCE], [SPECULATION], or [UNKNOWN]. Every hypothesis gets a probability score that updates as evidence comes in. This matters more than it sounds. Most AI responses blur the line between what is established and what is being inferred. RubberDuckAI forces the model to make that distinction explicit on every output, so you always know what ground you are actually standing on.
Default confidence starts at 50%. In chaotic or unpredictable domains, it is hard-capped at 65%. The model literally cannot pretend to know more than it does. That cap is doing real work. Anyone who has watched an AI confidently describe a market opportunity or validate a business idea knows the problem: the model sounds certain because certainty is what gets rewarded in training. This prompt breaks that pattern at the architecture level.
The Greek Chorus
This is the interesting part. Four adversarial personas fire when specific conditions are met:
- 🎯 SKEPTIC: appears when any hypothesis crosses 80% confidence
- PARANOID: fires on any claim without cited evidence, including the model’s own output
- HATER: activates when hypotheses haven’t been pruned in 10 turns
- CYNIC: triggers when you repeat an assertion without adding new information
None of them can change the analysis. They flag when something looks shaky. The main reasoning engine never adopts their framing. Think of them as auditors who can write memos but cannot touch the books. PARANOID is the one that surprises people the most. It fires on the model’s own unsupported claims, not just yours. So when the AI speculates about a competitor’s strategy without sourcing it, PARANOID calls that out too. The chorus is not there to make you feel challenged. It is there to keep the whole conversation epistemically honest.
The sycophancy firewall
This is the part that separates it from a regular prompt. The model is explicitly told to resist user framing. Probabilities only change when a structurally distinct argument introduces an unexamined variable. Not when you push back harder. Not when you repeat yourself louder. This directly addresses one of the most persistent failure modes in AI-assisted thinking: the model learns your preferred conclusion within a few exchanges and starts routing everything toward it. You think you are stress-testing an idea. You are actually rehearsing confirmation bias with a very articulate partner.
Every five turns, it runs a self-audit: checking for sycophancy drift, abandoned hypotheses, and gaps in adversarial coverage. It is logging its own behavior in real time. If it notices that it has been consistently validating your framing without pushback, that gets surfaced as part of the output. The audit is not a one-time safeguard. It is a recurring check built into the conversation loop itself.
🧠 Use Cases
- Working through a business decision where you’ve already made up your mind and need someone to pressure-test it before you spend money or time on it
- Research synthesis where you need to separate real evidence from wishful pattern-matching, especially when you are building a case for something you want to be true
- Any brainstorming session where the “yes-and” energy has been the problem, not the solution, and you need friction to actually improve the idea rather than just elaborate on it
- Preparing for a hard conversation or pitch where you want to anticipate the strongest version of the counterargument, not the weakest
Prompt of the Day
The full RubberDuckAI v2.2 prompt is the Reddit post itself, published by u/3xNEI in r/PromptEngineering. Copy the entire system prompt block and paste it into your custom instructions or system prompt field. The prompt is long by design. Every clause is doing something specific, so do not trim it down to save space. Use it whole or do not use it at all.
Then bring it a decision you have already made. See how long before the Chorus fires on you. For most people, SKEPTIC shows up within the first three or four exchanges. That is not a problem with your thinking. That is the point.
Most AI tools are optimized for making you feel heard. This one is optimized for making you right.
If breakdowns like this are useful, subscribe below to get one every week.
Rubber DuckAI: Custom instructions to help with ideation. Includes probabilistic hypothesis emergence and adversarial chorus.
by u/3xNEI in PromptEngineering