Premortem: how to spot problems before you decide

A premortem is a way to spot problems before you decide by imagining the decision has already failed. You picture yourself a year from now, assume the choice went badly, and write down every reason why it might have gone wrong. Then you use that list to fix weak spots, add safeguards, or choose differently while it's still cheap to change course.

It's the opposite of a postmortem, which looks back at what went wrong after the fact. The premortem idea was popularized in business by research psychologist Gary Klein, but it works just as well for personal choices like taking a job, adopting a pet or starting a side project. This guide shows exactly how to run one, alone or with others.

Why imagining failure works

When we're excited about a decision, we tend to see the reasons it will go well. Doubts get waved away. Planning is optimistic by default.

A premortem gets around that in a clever way. Instead of asking "what could go wrong?", which invites a quick "nothing much," it says: it did go wrong. Explain how.

That small shift matters. Treating failure as a fact rather than a possibility makes it easier to generate specific, concrete reasons. Your brain is good at explaining events that have already happened. The premortem borrows that skill and points it at the future.

It also gives you permission to voice doubts. Saying "I'm worried this won't work" can feel disloyal to a plan you're excited about. Saying "in the failure story, here's what happened" feels like part of the exercise.

How to run a premortem on your own

You need a pen, a page and about 20 minutes.

1. State the decision clearly

Write one sentence: "I'm deciding to [do this]." Be specific. "Take the Seattle job" is better than "make a career move."

2. Set the scene in the future

Pick a time far enough out that consequences would show up. Usually six months to a year. Then write: "It's [date]. This decision turned out badly."

Take a moment to really imagine it. Where are you? How do you feel? What are you telling your friends about it?

3. Write every reason it failed

Set a timer for ten minutes and list reasons, without judging them. Aim for quantity. Include:

• Practical reasons: money ran short, the timing was wrong, it took more hours than expected.
• People reasons: someone you depended on didn't come through, a relationship got strained.
• Personal reasons: you lost motivation, it wasn't what you actually wanted, you burned out.
• Outside reasons: the market shifted, a landlord sold the building, a rule changed.

Don't stop at the obvious ones. The most useful items are often the slightly embarrassing ones you wouldn't say out loud.

4. Sort the list

Go through each reason and mark it:

• Likely? Could this realistically happen?
• Serious? Would it really hurt if it did?

Circle anything that's both. Those are your real risks.

5. Decide what to do about each circled risk

For each one, choose a response:

• Prevent it: change the plan so it's less likely.
• Prepare for it: build a cushion so it hurts less.
• Set a tripwire: pick a clear sign that would tell you to change course.
• Accept it: acknowledge it and move on, knowingly.

6. Make the call

Now look at the decision again. Sometimes the premortem leaves you more confident, because the risks turned out to be manageable. Sometimes it shows the plan needs a big adjustment. Occasionally it shows you shouldn't do it at all. All three are wins.

A worked example: Hana and the rescue dog

Here's a hypothetical. Hana, 34, lives alone in a one-bedroom apartment and has fallen for a two-year-old rescue dog at a local shelter. She's ready to sign the adoption papers this weekend. Before she does, she runs a premortem.

Decision: "I'm adopting Biscuit this Saturday."

Future scene: "It's next October. Adopting Biscuit turned out badly."

Reasons it failed (her ten-minute list):

• My new job required more office days than I expected, and Biscuit was alone ten hours a day.
• He had separation anxiety and the neighbors complained about barking.
• Vet bills for an old injury were way more than I'd budgeted.
• My building raised the pet fee.
• I couldn't travel to see my family because I had no one to watch him.
• I got tired of the 6 a.m. walks in winter.
• He didn't get along with my sister's cat, so visits got awkward.
• I felt guilty all the time and it made me anxious.

Likely and serious: Long days alone, separation anxiety and barking, vet costs, and no backup care for travel.

Her responses:

• Long days: She checks her office schedule with her manager and prices a midday dog walker three days a week. She adds it to her budget.
• Separation anxiety: She asks the shelter what they've observed and whether he's been in a foster home. She books two sessions with a trainer for the first month.
• Vet costs: She asks for his medical records and gets a quote on pet insurance. She sets aside an emergency fund.
• Travel: She asks two friends whether they'd be willing to dog-sit occasionally and looks up a boarding place nearby.
• Tripwire: If barking complaints continue after two months of training, she'll talk to the shelter about options.

The premortem doesn't stop her. It makes her better prepared. She signs the papers a week later than planned, with a walker lined up and a budget that's realistic. If you're weighing the same choice, the should I get a dog page walks through the big questions.

Running a premortem with other people

Premortems are especially good for group decisions, like a couple choosing a house or friends planning a trip, because they let quieter doubts surface without anyone feeling like the naysayer.

A simple format:

1. One person explains the plan.
2. Everyone silently writes their own failure reasons for five minutes. Silence matters, so people don't anchor on whoever speaks first.
3. Go around and share one reason at a time until all are out.
4. Group similar reasons, then pick the top few risks together.
5. Agree on who will handle each one.

The rule is that no reason gets argued with during the sharing round. You're collecting, not debating.

Premortem pitfalls to avoid

Treating it as a reason to never act

Every decision can fail. The point isn't to find a risk-free option. It's to find risks you can do something about. If you finish a premortem and feel only dread, look at what you can prevent or prepare for, rather than at the whole list.

Only listing outside forces

It's easier to blame the economy than to write "I gave up after three weeks." Include your own likely behavior. That's usually where the most fixable problems live.

Skipping the follow-through

A list of risks with no response is just worry on paper. Each serious risk needs an action, a cushion, a tripwire, or a conscious decision to accept it.

Running it too late

A premortem is cheapest before you commit. Run it while you can still change the plan, not after the deposit is paid.

How it fits with other decision tools

A premortem looks for what could go wrong. It pairs well with:

• Second-order thinking, which asks "and then what?" to trace consequences forward.
• Scenario planning, which sketches good, likely and bad versions of the future. Our guide on how to make decisions under uncertainty walks through it.
• Reversibility checks, which tell you how much a premortem is worth doing. A choice that's easy to undo might not need one.

If you'd like help generating failure reasons you haven't thought of, the Choice companion can play the skeptic for you. Describe the plan, ask it to imagine the plan failed, and see what it comes up with. You can share a photo of a lease, a listing or a budget if that gives it more to work with.

The bottom line

A premortem takes 20 minutes and can save you months of trouble. Imagine your decision already failed, list every reason why, circle the ones that are likely and serious, and decide how to handle each. You'll either go ahead with a sturdier plan or change course before it costs you. Either way, you'll decide with your eyes open.