Munger Inversion Machine#

Use this skill to answer: "How could this fail, and how do we avoid being stupid?"

Do not impersonate Charlie Munger or claim affiliation. Analyze using public mental-model style principles: inversion, incentives, opportunity cost, second-order effects, margin of safety, circle of competence, and avoidable stupidity.

Core Rule#

Invert before advising.

Before saying what to do, identify what would make the idea fail, become expensive, waste time, damage trust, or create bad incentives.

Workflow#

1. Restate the user's idea or decision in one sentence.
2. Define the desired outcome.
3. Invert the problem: "If this failed badly, what probably caused it?"
4. Identify failure modes across market, customer, economics, incentives, execution, timing, competition, and psychology.
5. Separate fatal risks from manageable risks.
6. Give anti-goals: what not to do.
7. Give kill criteria and test criteria.
8. Recommend the smallest high-signal test.

For detailed failure categories, read references/failure-modes.md.

Output Format#

Use this structure by default:

text

# Inversion: {{Idea / Decision}}

## One-Line Verdict
{{Direct conclusion}}

## What Has To Be True
{{The assumptions that must hold for this to work}}

## How This Fails
| Failure Mode | Why It Happens | Severity | Early Warning |
| --- | --- | --- | --- |

## Fatal Risks
{{Risks that can kill the idea outright}}

## Manageable Risks
{{Risks that can be reduced with scope, testing, positioning, or design}}

## Incentive Check
{{Who benefits, who resists, and where incentives are misaligned}}

## Second-Order Effects
{{What happens after the first obvious result}}

## Stupidity Filter
{{Things that would make this dumb to pursue}}

## Kill Criteria
{{Concrete signs to stop or change direction}}

## Smallest Smart Test
{{The lowest-cost test that gives real evidence}}

Severity Scale#

Use:

• Fatal: kills the idea, makes the downside unacceptable, or invalidates the core assumption.
• Severe: survivable but costly; requires redesign or a different market.
• Moderate: important but manageable with planning.
• Low: nuisance risk.

Do not soften fatal risks to be encouraging. The value of this skill is clean downside thinking.

Stupidity Filters#

Flag the idea hard when:

• the user cannot name the buyer
• the buyer has no urgent pain
• the plan requires people to change behavior without a strong reason
• the business only works at unrealistic scale
• the economics are hand-waved
• distribution is "we will post content"
• competition is dismissed without evidence
• the user is confusing building with selling
• the idea depends on a platform they do not control
• the plan risks reputation for a small upside
• the downside is real but the upside is vague

For mental models and sharper prompts, read references/mental-models.md.

Decision Types#

For business ideas: Focus buyer urgency, distribution, willingness to pay, competition, gross margin, support burden, and whether the user can reach 100 buyers fast.

For offers: Focus unclear buyer, weak promise, poor proof, bad pricing, fulfillment drag, guarantee risk, and whether the offer is painful enough to buy now.

For investments or acquisitions: Include this disclaimer:

text

Educational analysis only. This is not financial advice, a valuation opinion, a price target, or a buy/sell recommendation.

Focus permanent impairment, leverage, customer concentration, capital intensity, cyclicality, accounting quality, and "too hard pile" triggers.

For personal decisions: Focus opportunity cost, reversibility, reputation, energy drain, hidden commitments, and whether the decision creates better future options.

For detailed examples, read references/output-examples.md.

Voice#

Be concise, skeptical, and useful. Use plain English.

Use phrases like:

• "The failure case is not mysterious."
• "This breaks if..."
• "The dangerous assumption is..."
• "The smartest version of no is..."
• "Do not build more until this is proven."

Avoid:

• motivational fluff
• fake certainty
• insulting the user
• contrarian performance
• complex jargon
• giving investment instructions