Summary: One Redditor built a prompt that makes ChatGPT assume your plan already failed, then work backward to tell you why. It’s blunter than asking for risks, and it’s already saved them from two bad spends.
Here’s the thing about asking AI “is this a good idea”: it wants to make you happy, so it tells you what you want to hear. Ask for risks instead and you get a polite bullet list you skim in ten seconds and forget. Neither one actually stops you from wiring money to a bad plan. Both questions leave the model free to hedge, and hedging is exactly what you don’t need when real money is about to leave your account.
u/Professional-Rest138 found a way around that. Instead of asking for an opinion, you hand the model a corpse and make it do the autopsy. The framing does the heavy lifting: there’s no “maybe” left once the outcome is fixed, only the mechanics of how it happened.
⚰️ The setup
Drop this once at the start of a chat:
For the rest of this conversation, when I use AUTOPSY, assume the thing I’ve described has already failed completely. Work backward and tell me exactly why it died, every weak point, in the order that killed it first. Be specific about what went wrong and when.
Then whenever you’re about to commit real money to something:
AUTOPSY: [describe the plan, the spend, the timeline, what you’re expecting to get out of it]
That’s the whole trick. You’re not asking the model to predict the future. You’re asking it to explain a death that’s already happened, and models are a lot more honest when the ending is fixed and all that’s left is the how. Give it specifics too, the exact dollar amount, the deadline, the metric you’re hoping to hit. Vague plans get vague autopsies. A plan with real numbers attached forces the model to point at the actual weak link instead of generic startup platitudes.
Two more in the same family
FIRST = tell me the one assumption this whole thing depends on. If that’s wrong, nothing else matters.
ODDS = give me an honest probability this works and what specifically would change your estimate. No encouragement.
Run FIRST before AUTOPSY. Most plans stand on exactly one load-bearing assumption, usually demand or your own available time, and everything else is decoration bolted on top. Naming that assumption takes ten seconds and sometimes ends the whole conversation right there, which is the cheapest way any of this can go. ODDS is the follow-up once you’ve survived AUTOPSY, because a plan can have zero obvious failure points and still be a coin flip. Ask what would move the number, and you usually get a short list of one or two things you can actually go check before spending anything.
Use cases
- 🔪 Before you sign a contractor, buy ad spend, or commit to a launch date
- 📋 Vetting a new offer or product line before you build it
- ⏱ Checking whether you actually have the capacity to run something, not just the budget
One detail from the original post is worth sitting with: one of the plans that died in autopsy wasn’t a bad idea at all. It would’ve worked. The poster just didn’t have the bandwidth to service it. AUTOPSY caught that a risk list never would have, because “not enough time” doesn’t show up on a standard pros and cons list. It only shows up when you’re forced to trace the actual sequence of events week by week, which is what the backward framing does automatically.
A fair pushback
The model could just as easily invent failure reasons that don’t apply, since it’s still trying to be “helpful” in whatever direction you point it. True. Treat the output as a prompt for your own judgment, not a verdict. It’s a better mirror, not an oracle. If a reason it gives doesn’t ring true for your situation, throw it out. The value isn’t in any single line item, it’s in the exercise of sitting with the failure before it happens instead of after.
Prompt of the day
For the rest of this conversation, when I use AUTOPSY, assume the thing I’ve described has already failed completely. Work backward and tell me exactly why it died, every weak point, in the order that killed it first. Be specific about what went wrong and when.
AUTOPSY: [your plan, the spend, the timeline, what you expect to get]
Next time you’re about to click “pay” on something bigger than a coffee, run it through this before your card does. Ten minutes now beats an autopsy on your bank account later.
Frequently Asked Questions
Q: Won’t the AI just make up failure scenarios to be helpful, same as it would say ‘yes, your idea is good’?
Fair point. The difference is in how you frame the request. By asking it to “work backward and tell me exactly why it died” with specificity , “Be specific about what went wrong and when” , you’re asking for diagnosis, not affirmation. Generic hand-waving gets exposed. This works best when you push back on vague answers and ask for concrete problems grounded in the actual plan, not imagined ones.
Q: When should I use FIRST, AUTOPSY, and ODDS? Should they run in sequence?
Yes. Start with FIRST to identify the one load-bearing assumption your entire plan hinges on (usually demand or capacity). If that’s shaky, you might stop there. Then run AUTOPSY to force a post-mortem on the full plan. Finally, use ODDS as a gut-check: honest probability plus what would actually change that estimate. The progression is: “What’s the core bet?” → “If this fails, why?” → “Realistically, what are the odds?”
Q: How detailed does my plan description need to be?
As specific as possible. Include actual spend amounts, timeline, expected outputs, and what success looks like. “We’ll spend $10k over 3 months expecting 100 signups” produces a much better autopsy than “we’ll try marketing.” Concrete constraints help the AI reason about real failure points instead of generic ones.
Q: What if the AUTOPSY rejects an idea that would’ve actually worked?
That’s the trade-off. The prompt surfaces weak points and hidden assumptions, not perfect decisions. The author’s example: one plan “would have worked fine, but they didn’t have capacity to service it.” The autopsy caught a capacity problem, not a fundamental flaw. The goal is avoiding catastrophic mistakes by exposing assumptions early, not catching every viable idea.
i run every business decision through one prompt before i commit money to it. it assumes the thing already failed and works backwards
by u/Professional-Rest138 in ChatGPTPromptGenius