Inversion is a thinking tool credited to mathematician Carl Jacobi and popularized by Charlie Munger. Instead of asking how to succeed, you ask the opposite: what would guarantee failure? Then you make sure you avoid every item on that list. The same problem, flipped, often becomes far easier to reason about - because failure modes are concrete and visible in ways that "the path to success" rarely is.
It works because your brain is better at spotting obvious dangers than at imagining a perfect plan. Listing what would sink you surfaces the avoidable mistakes hiding in plain sight, and clearing those off the board frequently leaves the winning move standing on its own.
Founders use it when stuck. Can't crack your go-to-market? Instead of optimizing a launch plan, list what would guarantee nobody buys: confusing pricing, no social proof, slow onboarding. Now you have three specific things to fix. Inversion turns a vague "how do I grow?" into a short, actionable checklist of failures to eliminate.
Common mistake
People treat inversion as pure pessimism and stop after listing what could go wrong, never converting those failure modes into the concrete fixes that are the whole point. Avoiding guaranteed failure is a starting move, not a substitute for a strategy that still has to win.
How to use it
Three ways to put it to work.
Everyday life
Trying to finally stick to a new exercise habit
Stop listing motivation tricks and instead ask what would guarantee you quit by week two. The answers: a 6am gym across town, no clothes laid out, and tracking nothing so progress feels invisible. Confirm you are doing none of these by inverting each into avoidance. So pick a 10-minute home workout, lay your shoes by the bed tonight, and put a single X on the calendar each day you move.
Tech
Onboarding flow for the new SaaS app keeps stalling
Instead of brainstorming features to boost activation, ask what would guarantee a new user never reaches the aha moment. The failure list: a 9-field signup form, no sample data so the dashboard is empty, and a verification email that takes 5 minutes. Check the flow and you are guilty of all three. Cut signup to email plus password, preload a demo project on first login, and ship the magic-link login this sprint.
Small business
New cafe has steady foot traffic but few regulars
Rather than chasing loyalty-program ideas, ask what would guarantee a first-timer never comes back. The list writes itself: a 12-minute wait at 8am, a barista who never learns a name, and a bathroom that is out of order. Walk the floor and you find two of the three are true today. Add a second person on the morning bar, fix the bathroom this week, and have staff repeat each customer's name back when they order.
Reckon · Thinking tool
Inversion
Carl Gustav Jacob Jacobi, popularized by Charlie Munger
What it is
Instead of asking how to succeed, ask what would guarantee failure. Avoid those things.
When to use it
When you're stuck optimizing a plan and can't see the path forward. Flip the question. List everything that would ensure you lose, then confirm you're not doing any of them.
Work through it.
Print this (use the Save as PDF button up top) and fill it in on paper. List everything that would guarantee failure on your current goal, then confirm you are not doing any of it.
01
THE GOAL: State the outcome you are trying to achieve as clearly as possible.
02
THE FAILURE LIST: Flip the question: what actions, decisions, or conditions would guarantee you fail at this? List at least eight.
Include things that are obvious and things that feel embarrassing to admit.
03
THE AUDIT: Go through each failure item and check: are you currently doing any of these, even partially? Mark them honestly.
04
THE REMOVALS: For each item you marked, write one action to stop, reduce, or reverse it.
05
THE FORWARD PLAN: With the failure paths cleared, write the three actions most likely to move you toward the goal. Inversion tells you what not to do; you still have to choose what to do.
Reckon · reckon.report · flip for the working template
Reckon · Working template
Inversion
Print double-sided. Read the how-to on the front; do the work here.