Check your plan before you do, not after
A pre-mortem analysis based on Gary Klein and Kahneman. The AI places you into a future where your plan has failed and reconstructs with you why. 30 percent more failure points found than with normal risk analysis.
Why pre-mortem Works
Standard risk analysis activates your optimism filter. A pre-mortem bypasses that filter by placing your thoughts in the future. You find more, you find concrete details, you intervene sooner.
30 percent more failure modes
Klein (1985) found that teams using a pre-mortem identified significantly more risks than teams using standard analyses.
Counteracting overconfidence bias
Kahneman wrote that this is the only technique that combats overconfidence and can be implemented in 30 minutes.
Concrete, not abstract
No vague “competitor might do something.” Specific failure modes with probability, impact, and early warning signs that you can monitor.
Ready in 30 minutes
Short structure, no workshop needed. Ideal for solo entrepreneurs, launches or decisions with a short turnaround time.
This is how it works pre-mortem
You share your plan, the AI takes you to a future where it has flopped and works back with you. Eight steps, each with a clear goal and output.
What you get back
Map out the plan
Decision, timeline, resources, success and failure definition, stakeholders. Vague is not enough.
Time travel
It's six months later and your plan has catastrophically failed. Concrete consequence.
15+ functioning modes
From seven categories: execution, assumption, external, communication, timing, scope, people.
Kans x impact scores
Rate each failure mode from 1 to 5 on probability and impact. Sort by risk score. Extract top 5.
Early warning signs
For critical risk, a metric, a threshold, and an intervention point.
Prevention or mitigation
What are you changing now, what's your plan if it does happen?.
Kill criteria
The points at which you stop. Decide this IN ADVANCE, before sunk cost traps you.
Go-no-go report
Brief summary with plan, risks, signals, adjustments, kill criteria, final assessment.
Example output
A pre-mortem on a fictional SaaS launch. Not all rows visible, but this is what the output looks like.
Pre-mortem: SaaS launch in 30 days
| Operating mode | Category | Thanks | Impact | Score |
|---|---|---|---|---|
| Onboarding friction reduces activation below 40 percent | Performance | 4 | 5 | 20 |
| The price is higher than the willingness to pay for early adopters | Assumption | 3 | 5 | 15 |
| Founder burns out before public launch | Men's | 3 | 4 | 12 |
| Concurrent X launches similar feature in Q3 | Extern | 2 | 5 | 10 |
| LinkedIn audience is not clicking through on launch post | Communication | 4 | 2 | 8 |
Without vs pre-mortem meeting
You're doing the same launch. Once without, once with a pre-mortem beforehand. The difference lies in what you anticipated in advance.
Without pre-mortem
- Your launch goes live, activation is 22 percent but you only discover it after two weeks.
- You didn't agree on a threshold, so you're hesitating between “waiting” or “pivoting”.
- You've already spent €3,000 on ads. Sunk cost is keeping you committed to the plan.
- Looking back, you say: I should have seen this coming. But in hindsight, every mistake in judgment is clear.
- Your kill criteria are set in panic, not from rationality.
Pre-mortem meeting
- You know in advance that activation below 40 percent is a red flag.
- On day 3, you’ll see activation is at 28 percent. You’ll intervene immediately with an onboarding fix.
- You know in advance: at 20 percent activation in week two, you stop the ads. No question.
- You don't roll into sunk costs. The kill criteria were fixed when you were still rational.
- You see three risks you would never have thought of alone. Time travel did the work.
The Prompt structure behind
The skill is built around a strict system prompt. You don't need to write a prompt yourself, but this way you'll know what's happening under the hood.
Frequently Asked questions
Frequently asked questions about the pre-mortem skill and how to use it in Claude.
Wat is een pre-mortem precies?
A pre-mortem is the reverse of a post-mortem. You do it BEFORE the launch or decision, not after. You imagine that your plan has failed and write back what happened. Gary Klein showed in his research that teams using this method found thirty percent more failure points than teams that did standard risk analyses.
What is this skill suitable for
For every decision with real consequences: a product launch, a hire that's not easily reversed, a pivot, a large expenditure, a market entry, an investment. Not for small daily choices, as the overhead would be too great.
How long does a session last
For a thoughtful pre-mortem on an important decision, allow thirty to sixty minutes. Kahneman specifically cited this as the reason the technique works in practice. You can do it faster if necessary, but then you lose nuance.
Why not just do a risk analysis
A standard risk analysis activates your optimism filter. You look for risks from a position where you still believe in the plan. The pre-mortem shifts you to a future where you no longer believe in the plan, because it has failed in that future. That small difference leads to a completely different thought process.
Does the skill provide go-no-go advice
Yes, as the final step. It is a fair judgement based on the risk profile that you have built together. Not as a rigid rule, but as a concrete signal. The final decision remains yours.
How do I install the skill in Claude
Download the zip, extract it, and upload SKILL.md into Claude via a skill or project. You can also directly use the content as a system prompt within a project. The skill works in Claude Pro, Team, and Enterprise.
Download de pre-mortem skill
A zip with SKILL.md. Upload in Claude via a skill or project. Works in Pro, Team, and Enterprise. No account needed, no payment, no fuss.
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