Poor Charlie's Almanack · Charlie Munger

Inversion: solve problems backward by asking how to fail

Curated by · reviewed 2026-05-31

Most people ask how to succeed. Inversion flips it: ask what would guarantee failure, then avoid those things. Avoiding stupidity turns out to be more reliable than seeking brilliance.

Inversion means solving a problem backward: instead of asking how to succeed, ask what would guarantee failure — then simply avoid that.

The mathematician Carl Jacobi's advice was 'invert, always invert.' Charlie Munger built a career on it. Most people attack a goal head-on: 'How do I get healthy, succeed, build a great team?' Inversion flips the question to 'What would reliably make me unhealthy, fail, or destroy a team?' — and then you avoid those things.

It works because failure is often easier to see than success, and avoiding stupidity is more reliable than engineering brilliance. Ask 'how do I have a happy marriage?' and you get vague advice. Ask 'what reliably wrecks a marriage?' and you get a concrete, avoidable list: contempt, stonewalling, never apologizing. Munger's line was, 'All I want to know is where I'm going to die, so I'll never go there.' You make progress not by adding clever moves but by removing the dumb ones.

Inversion is also a cure for over-confidence. Before launching a plan, run a 'pre-mortem': imagine it's a year from now and the plan failed badly — what killed it? The reasons you list are the risks to defuse now, while you still can. Forward thinking finds what might go right; inverted thinking finds what will go wrong, which is usually the more useful list.

Why it matters

Avoiding obvious failure is easier and more reliable than engineering success — so the fastest progress often comes from subtraction, not addition.

A common misreading

Inversion isn't pessimism or only dwelling on what could go wrong. It's a tool you pair with forward thinking — you still aim at the goal, you just also map the failure modes so you can sidestep them. Used alone it would paralyze you; used alongside ambition it protects it.

Put it to work

Test yourself

What question does inversion tell you to ask?
Show answer
Instead of 'how do I succeed?', ask 'what would guarantee failure?' — then avoid those things. Removing the dumb moves beats adding clever ones.

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FAQ

What is inversion thinking?
Approaching a problem backward — asking what would cause failure and avoiding it, rather than only asking how to succeed. Carl Jacobi summed it up as 'invert, always invert.'
What is a pre-mortem?
A planning exercise where you imagine your plan has already failed and ask why. It surfaces the risks worth defusing now — inversion applied to a decision before you make it.